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an important notice at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. production data. BQ25872 sluscq6 ? october 2016 BQ25872 14-v, 7-a, battery switch charger with integrated 10-bit adc 1 1 features 1 ? adapter input voltage range: 3 v to 14 v ? allow up to 14-v adaptor voltage ? highly integrated 7-a battery switch ? integrated mosfets and current sensing ? low r ds(on) (13-m ) mosfets for high current operation ? integrated high accuracy adc for system monitor ? vbus, vbat, vout, vdrop voltage ? input and battery current ? battery and vbus connector temperature ? linear regulation (ldo) mode operation ? four linear regulation loops: ibus, ibat, vbat and vout ? programmable linear regulation thresholds ? programmable safety protections ? vbus, vout, and vbat over voltage protections (ovp) ? ibus and ibat over current protection (ocp) ? ibus reverse current protection (rcp) ? vdrop (vbus-vout) ovp ? vbus connector and battery thermal protection ? thermal shutdown ? integrated input ovp fet control with fast ovp response (2 s) ? interrupt status output for host processor alert ? up to 1-mhz i 2 c read and write speed ? low battery leakage current in battery only mode ? wcsp package for small footprint 2 applications ? smart phone ? tablet pc 3 description the device is a 7-a battery switch charger with an integrated 10-bit adc. the high-current battery switch charger is a 13-m mosfet with reverse current blocking designed for high efficiency and minimal voltage drop. the high-charge current capability of the device makes it ideal for smartphones, tablets, and other portable devices with large battery capacity. the integrated 10-bit adc can measure input voltage and current, battery voltage and current, as well as battery temperature and input connector temperature. this allows the user application to continuously monitor the power input and battery charging parameters to ensure the safety of the battery charging. the flexible ovp and ocp thresholds for vbus, vout, and battery can be modified via i 2 c registers as the battery goes through constant current (cc) and constant voltage (cv) mode. the i 2 c serial interface of the device can operate at speeds up to 1 mhz and allows access to the adc ? s measurements of the different charging parameters and also allows for flexible software control of the device. the int pin provides instantaneous feedback to the host in case of a fault condition. i 2 c status registers allow the host to read the current status of all faults and events. the device comes in a dsbga package. device information (1) part number package body size (nom) BQ25872 yff (42) 2.5 mm x 3.1 mm (1) for all available packages, see the orderable addendum at the end of the data sheet. simplified schematic copyright ? 2016, texas instruments incorporated power supply vout sda/ scl vbus ovp gate vusb batp batn srp srn sw sys bat sda/ scl vbus switch-mode charger BQ25872 host system battery pack productfolder sample &buy technical documents tools & software support &community
2 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated table of contents 1 features .................................................................. 1 2 applications ........................................................... 1 3 description ............................................................. 1 4 revision history ..................................................... 2 5 pin configuration and functions ......................... 3 6 specifications ......................................................... 5 6.1 absolute maximum ratings ...................................... 5 6.2 esd ratings ............................................................ 5 6.3 recommended operating conditions ....................... 6 6.4 thermal information .................................................. 6 6.5 electrical characteristics ........................................... 7 6.6 timing requirements ............................................. 12 7 typical characteristics ........................................ 13 8 detailed description ............................................ 15 8.1 overview ................................................................. 15 8.2 functional block diagram ....................................... 16 8.3 feature description ................................................. 16 8.4 device functional modes ........................................ 28 8.5 i 2 c register maps .................................................. 29 9 application and implementation ........................ 58 9.1 application information ............................................ 58 9.2 typical application ................................................. 58 10 power supply recommendations ..................... 62 11 layout ................................................................... 62 11.1 layout guidelines ................................................. 62 11.2 layout example .................................................... 62 12 device and documentation support ................. 64 12.1 receiving notification of documentation updates 64 12.2 community resources .......................................... 64 12.3 trademarks ........................................................... 64 12.4 electrostatic discharge caution ............................ 64 12.5 glossary ................................................................ 64 13 mechanical, packaging, and orderable information ........................................................... 65 4 revision history date revision notes october 2016 * initial release.
3 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 5 pin configuration and functions dsbga package 42 pin yyf top view vout vout pmid vout vout pmid vout vout pmid vout vout pmid /int en batp batn ts_bus sda ts_bat gnd srp vusb scl vout vout chgstat srn ovpgate pmid xx xx vout vout pmid vout vout pmid 5 4 3 2 1 f e d c b g top view vbus vbus vbus vbus vbus vbus vbus 6 xx xx 5 4 3 2 1 b cd e f g a bottom view 6 vout vout pmid vout vout pmid vout vout pmid vout vout pmid /int en batp batn ts_bus sda ts_bat gnd srp vusb scl vout vout chgstat srn ovpgate pmid vout vout pmid vout vout pmid vbus vbus vbus vbus vbus vbus vbus a
4 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated pin functions pin i/o description name no. vout a3-g3, a4- g4 p device power output. connected to the drain of q2. pmid a5-g5 p tie pins to each other and leave floating. do not connect to any other pins. connected to the drain of q1 and source of q2. ts_bus b2 ai vbus connector temperature qualification voltage input. requires external resistor divider and voltage reference. gnd f2 p device ground. ts_bat d1 ai battery temperature qualification voltage input. requires external resistor divider and voltage reference. batn g1 ai negative input for battery voltage sensing. connect to negative terminal of battery pack. place 100- /1-k series resistance between pin and negative terminal. batp g2 ai positive input for battery voltage sensing. connect to positive terminal of battery pack. place 100- /1-k series resistance between pin and positive terminal. srn e1 ai negative input for battery current sensing. place r sense between srn and srp for battery current sensing. srp f1 ai positive input for battery current sensing. place r sense between srn and srp for battery current sensing. vbus a6, b6, c6, d6, e6, f6, g6 p device power input. en d2 di active high device enable. pull low to disable device. adc not available when device is disabled. chgstat e2 di open drain, active low battery switch indicator. connect to pull-up voltage via 10-k pull-up resistor. this pin will assert low if battery switch is enabled and will go high when battery switch is disabled (due to fault or charge disabled or por event). int c2 do open drain, active low interrupt output. connect to pull-up voltage via 10-k pull-up resistor. normally low, the int pin asserts low to report status and faults. keep constant low until the host reads this register 0x03, 0x04. sda c1 dio i 2 c interface data. connect to pull-up voltage via 1-k pull-up resistor. scl b1 di i 2 c interface clock. connect to pull-up voltage via 1-k pull-up resistor. ovpgate a2 ao external ovp fet n-channel gate drive pin. vusb a1 ai device power input. place a 500- series resistor between this pin and usb supply voltage.
5 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated (1) stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions . exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 6 specifications 6.1 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) (1) min max unit voltage range (with respect to gnd) vusb (en = low, or chg_en = ' 0 ' ) ? 2 40 v vbus (en = low, or chg_en = ' 0 ' ) ? 2 22 v vout (en = low, or chg_en = ' 0 ' ) ? 0.3 7 v srp, srn, batp, batn ? 0.3 7 v int, sda, scl, en, chgstat ? 0.3 7 v ts_bus, ts_bat ? 0.3 5 v maximum voltage difference srp ? srn ? 0.5 0.5 v vout ? vbus ? 22 7 v output sink current int 6 ma operating free-air temperature range ? 40 85 c junction temperature, t j ? 40 150 c storage temperature, t stg ? 65 150 c (1) jedec document jep155 states that 500-v hbm allows safe manufacturing with a standard esd control process. (2) jedec document jep157 states that 250-v cdm allows safe manufacturing with a standard esd control process. 6.2 esd ratings value unit v (esd) electrostatic discharge human-body model (hbm), per ansi/esda/jedec js-001 (1) 2000 v charged-device model (cdm), per jedec specification jesd22- c101 (2) 500 v
6 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 6.3 recommended operating conditions over operating free-air temperature range (unless otherwise noted) min nom max unit vusb en = low, or chg_en = ' 0 ' 2.8 14 v vbus en = high, or chg_en = ' 1 ' 2.8 6 v vout en = high, or chg_en = ' 1 ' 2.8 6 v batp, batn 0 6 v srp ? srn differential voltage between srp and srn ? 0.2 0.2 v ts_bus, ts_bat ts pin voltage range 0 3 v sda, scl, addr, int, en ts pin voltage range 0 5 v iout maximum current from vbus to vout ? 3 7 a t j operating junction temperature range ? 40 85 c (1) for more information about traditional and new thermal metrics, see the semiconductor and ic package thermal metrics application report, spra953 . 6.4 thermal information thermal metric (1) BQ25872 unit yff (dsbga) 42 pins r ja junction-to-ambient thermal resistance 50.0 c/w r jc(top) junction-to-case (top) thermal resistance 0.2 c/w r jb junction-to-board thermal resistance 8.9 c/w jt junction-to-top characterization parameter 0.1 c/w jb junction-to-board characterization parameter 8.9 c/w r jc(bot) junction-to-case (bottom) thermal resistance n/a c/w
7 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 6.5 electrical characteristics unless otherwise noted, the specification in the following table applies over operating ambient temperature range ? 40 c t a 85 c. typical values are for t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit quiescent currents i q_op adaptor operation quiescent current adc disabled (adc_en = 0), charge disabled (chg_en = 0), en = low, v vusb = 3.6 v, vout floating, current into vbus and vusb 115 145 a adc enabled (adc_en = 1), charge disabled (chg_en = 0), en = high, v vusb = 3.6 v, vout floating, current into vbus and vusb 1.75 2.0 ma i q_bat battery quiescent current adc disabled (adc_en = 0), charge disabled (chg_en = 0), en = low, v vout = 3.6 v, current into vout 20 30 a adc disabled (adc_en = 0), charge disabled (chg_en = 0), en = high, v vout = 3.6 v, current into vout 80 120 a adc enable (adc_en = 1), charge disabled (chg_en = 0), en = high, v vout = 3.6 v, current into vout 1.35 1.75 ma resistance and leakage r on vbus to vout resistance v vbus = 3.6 v, t a = 25 c 13 16 m v vbus = 3.6 v, ? 40 c t a 85 c 13 22 m v vbus_pd vbus pull-down resistance vbus_pd_en = ' 1 ' 0.5 1.0 1.35 k internal thresholds v usb_present rising 3.2 v falling hysteresis 375 mv v bus_present rising 2.8 v falling hysteresis 120 mv v bat_insert rising 2.8 v falling hysteresis 120 mv t shut internal thermal shutdown- rising 150 c t shut_hys tshut falling hysteresis 30 c i rcp current from vout to vbus rcp_set = ' 0 ' 0.10 0.25 0.40 a rcp_set = ' 1 ' 2.75 3.00 3.25 a i scp short circuit current from vbus to vout 10 a v ovpset vusbovp_setting = 6.5 v leave pin floating, resistance to ground 100 k vusbovp_setting = 10.5 v tie to gnd with a 22-k series resistor, resistance to ground 17.6 26.4 k vusbovp_setting = 14.0 v short to ground, resistance to ground 2.0 k
8 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated electrical characteristics (continued) unless otherwise noted, the specification in the following table applies over operating ambient temperature range ? 40 c t a 85 c. typical values are for t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit v usb_ovp rising vusbovp_i2c = ' 00 ' 5.6 6.0 v falling hystersis vusbovp_i2c = ' 00 ' 100 mv rising vusbovp_i2c = ' 01 ' or ovpset pin = floating (vusbovp_12c = ' 01 ' , ' 10 ' or ' 11 ' ) 6.5 7.0 v falling hystersis vusbovp_i2c = ' 01 ' or ovpset pin = floating (vusbovp_12c = ' 01 ' , ' 10 ' or ' 11 ' ) 120 mv rising vusbovp_i2c = ' 10 ' (ovpset pin = mid or ground) or ovpset pin = low (vusbovp_12c = ( ' 10 ' or ' 11 ' ) 10.8 11.3 v falling hystersis vusbovp_i2c = ' 10 ' (ovpset pin = mid or low ) or ovpset pin = low (vusbovp_12c = ( ' 10 ' or ' 11 ' ) 200 mv rising vusbovp_i2c = ' 11 ' and ovpset pin = low 14.5 15.0 v falling hystersis vusbovp_i2c = ' 11 ' and ovpset pin = low 300 mv protection threshold and accuracy v drop_ovp vdrop ovp range vbus ? vout. programmable range 0 1000 mv vdrop ovp step size 0 mv vdrop_ovp 640 mv 10 mv 700 mv < vdrop_ovp 1000 mv 100 mv vdrop ovp comparator accuracy vdrop_ovp = 80 mv ? 8.0% 8.0% vdrop_ovp = 160 mv ? 5.0% 5.0% v drop_alm vdrop alm range vbus ? vout. programmable range 0 1000 mv vdrop alm step size 0 mv vdrop_ovp 640 mv 10 mv 700 mv < vdroop_ovp 1000 mv 100 mv vdrop alm comparator accuracy vdrop_alm = 80 mv ? 8.0% 8.0% vdrop_alm = 160 mv ? 5.0% 5.0% vdrop alm falling hysteresis 10 mv v bus_ovp vbus ovp range programmable range 4.20 6.51 v vbus ovp step size 30 mv vbus ovp comparator accuracy vbus_ovp = 4.20 v ? 1.25% 1.25% vbus_ovp = 4.50 v ? 1.25% 1.25% vbus_ovp = 5.49 v ? 1.25% 1.25% vbus ovp falling hysteresis vbus_ovp = 4.20 v 50 mv i bus_reg ibus reg range programmable range 0 6.3 a ibus reg step size 100 ma ibus reg accuracy ibus_reg = 1.5 a, ? 40 c t a 85 c ? 20% 20% ibus_reg = 1.5 a, t a = 25 c ? 10% 10% i bus_ocp ibus ocp range programmable range 0 7.5 a ibus ocp step size 500 ma ibus ocp comparator accuracy ibus_ocp = 1.5 a ? 20% 20%
9 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated electrical characteristics (continued) unless otherwise noted, the specification in the following table applies over operating ambient temperature range ? 40 c t a 85 c. typical values are for t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit i bat_reg ibat reg range programmable range 0 6.35 a ibat reg step r sense = 10 m 50 ma ibat reg accuracy ibat_reg = 2 a, r sense = 10 m ? 6.5% 6.5% ibat_reg = 5 a, r sense = 10 m ? 4% 2% i bat_ocp ibat ocp rising threshold percentage of ibat_reg threshold, ibat_reg = 6 a 105% ibat ocp falling threshold percentage of ibat_reg threshold, ibat_reg = 6 a 102.5% v bat_reg vbat reg range programmable range 4.2 4.975 v vbat reg step size 12.5 mv vbat reg accuracy vbat_reg = 4.35 v ? 1.5% 1.0% vbat_reg = 4.40 v ? 1.5% 1.0% v bat_ovp vbat ovp rising threshold percentage of vbat_reg threshold, vbat_reg = 4.40 v 104% vbat ovp falling threshold percentage of vbat_reg threshold, vbat_reg = 4.40 v 102% v out_reg vout reg range programmable range 4.2 4.975 v vout reg step size 25 mv vout reg accuracy vout_reg = 4.35 v ? 0.5% 0.5% vout_reg = 4.40 v ? 0.5% 0.5% v out_ovp vout ovp rising threshold percentage of vout_reg threshold, vout_reg = 4.40 v 104% vout ovp falling threshold percentage of vout_reg threshold, vout_reg = 4.40 v 102% ts bus_flt ts_bus pin voltage range programmable range 0.2 1.4 v ts_bus step size 25 mv ts_bus comparator accuracy ts_bus = 0.4 v ? 4.0% 4.0% ts_bus = 0.7 v ? 4.0% 4.0% ts_bus hysteresis 1% ts bat_flt ts_bat pin voltage range programmable range 0.2 1.4 v ts_bat step size 25 mv ts_bat comparator accuracy ts_bat = 0.4 v ? 2.5% 2.5% ts_bat = 0.6 v ? 2.5% 2.5% ts_bat hysteresis 1%
10 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated electrical characteristics (continued) unless otherwise noted, the specification in the following table applies over operating ambient temperature range ? 40 c t a 85 c. typical values are for t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit integrated adc: temperature range: 0 c t a 85 c adc res resolution 10 bits t adc_conv adc individual measurement and conversion time 30 s t adc_int adc samples interval in averaging mode 300 s range ibat ibat current measurement range 0 7.504 a res ibat ibat current lsb 8 ma acc ibat ibat accuracy ibat = 6 a ? 2% 2% range ibus ibus current measurement range 0 7.504 a res ibus ibus current lsb 8 ma acc ibus ibus accuracy ibus = 1.6 a ? 5% 5% acc ibus ibus accuracy ibus = 5 a ? 4.5% 4.5% range vbus vbus voltage measurement range 2.048 6.140 v res vbus vbus voltage lsb 4 mv acc vbus vbus accuracy vbus = 4.5 v ? 20 20 mv range vusb vusb voltage measurement range 2.048 6.140 v res vusb vusb voltage lsb 4 mv acc vusb vusb accuracy vusb = 4.5 v ? 20 20 mv range vbat vbat voltage measurement range 2.048 6.140 v res vbat vbat voltage lsb 4 mv acc vbat vbat accuracy vbat = 4.4 v -12 12 mv range vout vout voltage measurement range 2.048 6.140 v res vout vout voltage lsb 4 mv acc vout vout accuracy vout = 4.4 v -12 12 mv range vdrop vdrop voltage measurement range 0 1000 mv res vdrop vdrop voltage lsb 1 mv acc vdrop vdrop accuracy vdrop = 200 mv -10 10 mv range ts_bus ts_bus voltage measurement range 0 2.420 v res ts_bus ts_bus voltage lsb 4 mv acc ts_bus ts_bus accuracy ts_bus = 400 mv -13.4 13.4 mv range ts_bat ts_bat voltage measurement range 0 2.420 v res ts_bat ts_bat voltage lsb 4 mv acc ts_bat ts_bat accuracy ts_bat = 400 mv -13.4 13.4 mv
11 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated electrical characteristics (continued) unless otherwise noted, the specification in the following table applies over operating ambient temperature range ? 40 c t a 85 c. typical values are for t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit logic i/o threshold (en, int, addr) v il input low threshold level i sink = 5 ma 0.4 v v ih input high threshold level i sink = 5 ma 1.3 v i leak ( int) high level leakage current v pull-up = 3.3 v 5 a i leak ( chgstat) high level leakage current v pull-up = 3.3 v 5 a i leak (en) high level leakage current v pull-up = 3.3 v 10 a i 2 c timings v il input low threshold level v pull-up = 1.8 v, sda and scl 0.4 v v ih input high threshold level v pull-up = 1.8 v, sda and scl 1.3 v v ol output low threshold level i ol = 20 ma 0.4 v i bias high-level leakage current v pull-up = 1.8 v, sda and scl 5 a f scl scl clock frequency 1 mhz
12 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 6.6 timing requirements min nom max unit protection osc oscillator frequency 1.8 2 2.4 mhz t vbus_ovp vbus ovp deglitch time, vbus_ovp_dly = 0 8 s t vbus_ovp vbus ovp deglitch time, vbus_ovp_dly = 1 128 s t ibus_ocp_blank ibus ocp deglitch time, ocp_res = 0 8 s t ibus_ocp ibus ocp deglitch time in hiccup mode, ocp_res = 1 8 s t ibus_ocp_hp retry wait time for ibus ocp in hiccup mode, ocp_res = 1 100 ms t ibus_ocp_rst hiccup count reset timer 400 ms t ibat_ocp ibat ocp deglitch time 512 s t vdrop_ovp vdrop deglitch time 64 s t vbat_ovp vbat ovp deglitch time 64 s t vout_ovp vout ovp deglitch time 64 s t ldo_res ldo response time for ibus, ibat, vbat, vout 1 ms t ldo_active ldo active signal deglitch time 128 s t ts_otp ts_bat and ts_bus deglitch time 100 ms t irev reverse current protection (rcp) deglitch time 8 s t scp short circuit protection (rcp) deglitch time 2 s t on_vout vout soft-start rise time 0.5 ms t off_fet battery switch turn off time 1 s t off_flt battery switch turn-off time, r vbus = 100 , c vbus = 0 f, when v vusb > vusb ovp to v ovpgate falling (95 % threshold) 100 ns t wtdg watchdog timer watchdog[3:2] = 01 0.5 s watchdog[3:2] = 10 1 s watchdog[3:2] = 11 2 s
13 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 7 typical characteristics figure 1. vbat adc vs temperature at 4.4 v figure 2. ibat adc vs temperature at 2 a figure 3. ibat adc vs temperature at 6 a figure 4. vout adc vs temperature at 4.4 v figure 5. quiescent current with battery only vs temperature figure 6. r dson vs temperature temperature ( q c) v out (v) -10 15 40 65 90 4.36 4.37 4.38 4.39 4.4 4.41 4.42 4.43 4.44 d004 v out = 4.40 v temperature ( q c) v bat (v) -10 15 40 65 90 4.36 4.37 4.38 4.39 4.4 4.41 4.42 4.43 4.44 d001 v bat = 4.40 v temperature ( q c) i bat (a) -10 15 40 65 90 1.9 1.92 1.94 1.96 1.98 2 2.02 2.04 2.06 2.08 2.1 d002 i bat = 2.0 a temperature ( q c) i q_bat ( p a) -50 -25 0 25 50 75 100 0 5 10 15 20 25 30 35 40 d005 en = low, adc disabled, chg_en = 0 temperature ( q c) rds (on) (m : ) -50 -25 0 25 50 75 100 8 9 10 11 12 13 14 15 16 17 d006 v bus = 3.0 v v bus = 3.6 v temperature ( q c) i bat (a) -10 15 40 65 90 5.9 5.92 5.94 5.96 5.98 6 6.02 6.04 6.06 6.08 6.1 d003 i bat = 6.0 a
14 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated typical characteristics (continued) figure 7. vout regulation vs temperature figure 8. vbat regulation vs temperature figure 9. ibat regulation vs temperature at 2 a figure 10. ibat regulation vs temperature at 6 a temperature ( q c) i bat (a) -50 -25 0 25 50 75 100 1.9 1.92 1.94 1.96 1.98 2 2.02 2.04 2.06 2.08 2.1 d009 i bat = 2.0 a temperature ( q c) i bat (a) -50 -25 0 25 50 75 100 5.9 5.92 5.94 5.96 5.98 6 6.02 6.04 6.06 6.08 6.1 d010 i bat = 6.0 a temperature ( q c) v out (v) -50 -25 0 25 50 75 100 4.26 4.28 4.3 4.32 4.34 4.36 4.38 4.4 4.42 4.44 4.46 d007 v out = 4.35 v v out = 4.40 v temperature ( q c) v bat (v) -50 -25 0 25 50 75 100 4.3 4.32 4.34 4.36 4.38 4.4 4.42 4.44 4.46 d008 v bat = 4.35 v v bat = 4.40 v
15 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8 detailed description 8.1 overview the BQ25872 is an i 2 c controlled device and a single cell li-ion battery charger. the device allows 7-a charging current with 13-m mosfets for minimum power loss. a 10 -bit adc, four linear regulation loops and multiple ovp and ocp are integrated for host monitoring and safe operation of the device. 8.1.1 device protection overview the following table summarizes the protection features implemented in the device. table 1. protection features overview protection name description respond vusb ovp monitors vusb voltage and compares to the voltage defined by ovpset and vusbovp_i2c (reg29[3:2]) turn off external ovpfet via ovpgate vbus_ovp monitors vbus voltage and compares to the threshold programmed in reg 0a turn off load switch after a deglitch time of t vbus_ovp vout_reg monitors vout voltage and compares to the threshold programmed in reg 0b enable linear regulation of battery switch within a response time of t ldo_res vout_ovp monitors vout voltage and compares to 1.04 times of the threshold programmed in reg 0b turn off load switch after a deglitch time of t vout_ovp vdrop_ovp monitors voltage difference between vbus and vout (vbus ? vout) and compares to the threshold programmed in reg 0c turn off load switch after a deglitch time of t vdrop_ovp vdrop_alm monitors voltage difference between vbus and vout (vbus ? vout) and compares to the threshold programmed in reg 0d int is asserted low to alert host vbat_reg monitors vbat voltage and compares to the threshold programmed in reg 0e enable linear regulation of battery switch within a response time of t ldo_res vbat_ovp monitors vbat voltage and compares to 1.04 times of the threshold programmed in reg 0e turn off load switch after a deglitch time of t vbat_ovp ibat_reg monitors battery current measured by sensing resistor and compares to the threshold programmed in reg 0f enable linear regulation of battery switch within a response time of t ldo_res ibat_ocp monitors vbat voltage and compares to 1.05 times of the threshold programmed in reg 0e turn off load switch after a deglitch time of t vbat_ovp ibus_ocp monitors input current and compares to the threshold programmed in reg 09 turn off load switch after a deglitch time of t ibus_ocp ibus_reg monitors input current and compares to the threshold programmed in reg 10 enable linear regulation of battery switch within a response time of t ldo_res ibus_rcp monitors current flowing from battery to adaptor and compares to the threshold selected in reg 06 turn off load switch after a deglitch time of t ibus_rcp ts_bus_otp monitors temperature based on voltage measured by a negative temperature coefficient (ntc) resistor at vbus and compares to the threshold programmed in reg 11 turn off load switch after a deglitch time of t ts_otp ts_bat_otp monitors temperature based on voltage measured by a negative temperature coefficient (ntc) resistor at battery and compares to the threshold programmed in reg 12 turn off load switch after a deglitch time of t ts_otp
16 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.2 functional block diagram 8.3 feature description 8.3.1 device power up the internal bias circuits of the device are powered from higher of the two voltages among vusb, vbus and vout as long as one of the pins is above its respective present threshold (vusb present , vbus present , or vout present ). once either v vusb > vusb present, v vbus > vbus present , or v vout > vout present is qualified, the device is considered to have a valid power supply. however, the device will begin to draw current from vbus or vout (depending upon which supply is present) once either supply is above its respective uvlo threshold. vbus scl sda en int ts_bus ts_bat internal charge pump q1 q2 vout batp batn srp srn gnd + protection digital core vbat_adc ibat_adc tbus_adc tbat_adc vdrop_adc 10-bit adc + + + + + + + + + + + + rcp vout-vbus ibus_ocp ibus rcp rcp ts_bat_flt ts_bus_flt vbus_ovp vbus vdrop_ovp vdrop_alm vbus-vout vout_reg vout ibat_reg vbat_reg vbus-vout vbus_pd_en vusb_adc vout_adc die_temp_adc vbus_adc ibus_adc copyright ? 2016, texas instruments incorporated chgstat internal power supply vusb + ovpset external fet charge pump ovpgate vusb_ovp
17 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.2 battery switch (q1 + q2) the device contains an integrated 13m battery switch that is capable of handling up to 7 a of current. this battery switch can be controlled by the host via chg_en i 2 c bit. the device can be disabled, including the battery switch and the i 2 c core, by pulling the en pin low. to turn on the battery switch charger for conduction, the en pin must be pulled high, chg_en bit must be set to ? 1 ? , and no fault conditions must be present (unless they have been disabled in event_1_en register). see event_1 and event_2 registers for a list of faults/events. in the event of a fault/event, the battery switch will be automatically disabled, and the host will be notified via the int for error reporting if the corresponding event bit is unmasked in the event_x_mask registers. in order to ensure that the ibus ocp threshold is not falsely tripped during turn-on of the battery switch, the device employs a soft-start scheme where the battery switch is slowly turned to minimize the inrush current. the rise time of vout is t on_vout . 8.3.3 integrated 10-bit adc for monitoring with the integrated 10-bit adc of the device, the user application can monitor the voltage of vusb, the voltage and current of vbus, voltage of vout and vusb, and the voltage and current of the battery. the adc is also used for temperature reporting of the internal junction temperature, battery temperature (via external resistor divider and ntc thermistor), and vbus connector temperature (via external resistor divider and ntc thermistor). the integrated adc has a conversion time of t adc_conv for each parameter (except ibat_adc which has conversion time of 2 x t adc_conv ). the total conversion time of all parameters (in 1-shot mode) is between 80 s and 140 s. the rate at which the adc output registers are updated depends on the settings of adc_avg_en, adc_samples, and the parameter conversions that have been enabled in the adc_mask register. to enable the adc, the adc_en bit must be set to ? 1 ? . the adc is allowed to operate if either v vusb > vusb present , v vbus > vbus present or v vout > vout present is valid. if adc_en is set to ? 1 ? before vusb or vbus or vout reach their respective present threshold, then adc conversion will be postponed until one of the power supplies reaches their respective present threshold. if en pin is asserted low, then adc conversion is not allowed. the integrated adc has two conversion rate options ? 1-shot conversion (only one conversion) and continuous conversion (back-to-back conversions). to select the appropriate conversion rate, the adc_rate bit must be set accordingly ( ? 0 ? for 1-shot, ? 1 ? for continuous). if adc_avg_en is set to ? 0 ? , the adc will convert instantaneous measurements. if adc_avg_en is set to ? 1 ? , the average measurement of a parameter (in both continuous and 1-shot mode) will be determined by the setting of adc_samples. if the user reads the output registers before the adc averaging is complete, then the read-back value would be unchanged from the previous converted measurement. however, the value in the register will not change during the read-back of the register(s). if the measured signal is outside of the range of the adc output register in question, the reported value in the adc will be clamped to the min/max of the range specified. when adc_en is changed from 1 to 0, the adc registers will maintain their values from the previous converted measurement.
18 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) the user application has the option of selecting which parameters (voltage, current, temperature) the adc needs to convert when the adc is set to continuous conversion mode (adc_rate is set to ? 1 ? ) or in 1-shot mode (adc_rate is set to ? 0 ? ). by default, all parameters ( vusb_adc, ibus_adc, vbus_adc, ibat_adc, vbat_adc, vout_adc, vdrop_adc, tbus_adc, tbat_adc, tdie_adc) will be converted in 1-shot and continuous conversion mode unless disabled in the adc_mask register. if an adc parameter is masked (by setting the corresponding bit in the adc_mask_x register), then the value in that register will be from the last valid adc conversion or the default por value (which is all zeros if no conversions have taken place). if an adc parameter is masked in the middle of an adc measurement cycle, the device will finish the conversion of that parameter in the current conversion cycle and will not convert that parameter starting the next conversion cycle. even though no conversion takes place when all adc measurement parameters are masked off, the adc circuitry is active and ready to begin conversion as soon as one of the bits in the adc_mask register is set to ? 0 ? . the adc_done bit signals when a 1-shot mode conversion is completed. during continuous conversion mode, this bit is always set to ? 0 ? . the adc_en bit controls when the adc is enabled for a conversion. upon enabling the adc, the adc conversion will follow the settings in adc_avg_en, adc_sample, and adc_rate. adc conversion operates independently of the faults present in the device. adc conversion will continue even after a fault has occurred (that causes the battery switch to be disabled), and the host must set adc_en = ? 0 ? to disable adc. adc readings are only valid for dc states of the signals, not for transients. 8.3.4 linear regulation mode (ldo) the device employs ldo mode that helps regulate vout voltage, battery voltage, input current and battery current. in an event that the vout_reg, vbat_reg, ibus_reg or ibat_reg threshold is exceeded, the battery switch will act as an ldo and will regulate vout, vbat, ibus and ibat (depending upon which threshold is exceeded). the purpose of ldo mode is to provide temporary protection until the host is able to read the event_x registers (upon int trigger), adc output registers, and then update the adapter voltage accordingly. when vout_reg, vbat_reg, or ibat_reg threshold is exceeded, the response time of the ldo will be 1ms. depending upon which ldo mode event occurs, the corresponding bit (vbat_reg_ldo, ibat_reg_ldo, vout_reg_ldo) will be set in event_1 register and int will be asserted low to alert the host (if the corresponding bit is not masked in event_1_mask register).
19 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.5 protection features the device contains various protection features that are active depending upon the states of various inputs: ? if v vusb > vusb present , v vbus > vbus present , v vout > vout present , en asserted high, and chg_en = ? 1 ? ? active protection: vbus_ovp, ibus_ocp, vout_ovp, vbat_ovp, ibat_ocp, scp, rcp, vdrop_ovp ? if v vusb > vusb present , v vbus > vbus present , v vout > vout present , en asserted high, and chg_en = ? 0 ? ? active protection: vbus_ovp, ibus_ocp, vout_ovp, ibat_ocp, scp, rcp, vdrop_ovp ? vbat_ovp active until vbat ovp condition is over (protection becomes inactive on falling threshold of vbat_ovp, which is 102% of vbat_reg setting) ? if v vusb > vusb present , en asserted low, and chg_en = ? 0 ? ? active protection: vusb_ovp ? if v vusb < vusb present , v vbus > vbus present , v vout > vout present , and chg_en = ? 0 ? ? active protection: vusb_ovp ? vout present , vbus present , and vusb present comparators active tripping any of these protection faults will cause the battery switch to be disabled (unless the protection is disabled in event_1_en and event_2_en registers) and an interrupt to be issued on the int pin (see int pin, event_x registers, event_x_mask registers section for details of when int is toggled). 8.3.5.1 reverse current protection (rcp) the device monitors the current flow from vbus to vout to ensure there is no reverse current (current flow from vout to vbus). in an event that a reverse current flow is detected, the battery switch is disabled within t off_fet after a deglitch time of t irev and chg_en is set to ? 0 ? . host intervention is required to set chg_en to ? 1 ? to enable the power switch again. the rcp threshold is set by the rcp_set bit. reverse current protection is always active when the device has valid power. the rcp threshold is based on the rcp_set bit setting in the control register. it has a response delay of t irev . when rcp is tripped, ibus_irev_flt bit in the event_1 register is set to ? 1 ? , and int is asserted low to alert the host (unless masked by ibus_irev_mask). 8.3.5.2 internal thermal shutdown the device monitors the die junction temperature and the battery switch is disabled when device junction temperature reaches tshut within t off_fet and chg_en is set to ? 0 ? . when the internal thermal shutdown is triggered, int is asserted low to alert the host, and the device temperature must drop by tshut_hys before the battery switch can be enabled again (host must enable battery switch). while the tshut condition persists (and before the junction temperature dropped by tshut_hys), all other functions are unaffected. if the die_temp_flt threshold has been crossed, tshut_flt bit in event_2 register is set to ? 1 ? , and int will assert low to alert the host (no mask bit for tshut_flt). after the tshut_flt is cleared by the host with a register read, it is possible the tshut_flt bit is set again if the die junction temperature has not reduced by tshut_hys. die_temp_flt allows the user to select tshut thresholds between different junction temperatures as the thermal shutdown point. die_temp_adc is the die (junction) temperature of the device that is measured via the 10-bit adc. the adc measurement (die_temp_adc) is independent of the tshut fault that triggers tshut_flt in the event_x register. therefore, it is possible to have the adc output value be a higher value that the die_temp_flt threshold, while the tshut fault has not yet been triggered. 8.3.5.3 input overvoltage protection the device integrates the functionality of an overvoltage protector. the device can be paired with an external n- channel fet to block input voltages higher than the setting programmed by ovpset pin. the device senses the input (via vusb) and turns the external n-channel fet on or off (via ovpgate pin) to protect the downstream system. this eliminates the need for a separate ovp chip to protect the overall system. the integrated ovp feature has a reaction time of t off_flt (the actual time to turn off ovp fet will be longer and depends upon the
20 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) fet gate capacitance) and does not depend on the en pin status (i.e., feature is always active as long as v vusb > vusb present ). if the en pin is pulled high, then i 2 c communication to the device is available, and the ovp threshold can then be changed via the vusbovp_i2c bits. the final vusb ovp threshold is set by the lower setting of the ovpset pin and the vusbovp_i2c bits. vusbovp_i2c bits are not reset when en is asserted low and are only reset by reg_rst or a por event. 8.3.5.3.1 ovpset pin the data on the sda line must be stable during the high period of the clock. the high or low state of the data line can only change when the clock signal on the scl line is low. one clock pulse is generated for each data bit transferred. the default power up ovp threshold can be set via the ovpset pin with a single external resistor to one of three preset thresholds ? 6.5 v, 10.5 v, and 14 v. the ovpset pin will source a current to determine the resistance on the pin, and then set the ovp threshold accordingly. the ovpset pin will follow these threshold assignments: ? highest pin threshold (floating) = 6.5-v ovp threshold ? lowest pin threshold (tied to gnd) = 14.5-v ovp threshold ? mid-point pin threshold (22 k to gnd) = 10.5 v
21 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.5.4 ibus and vbus protection over-current protection on vbus (ibus_ocp) monitors the current flow from vbus to vout pins. ibus_ocp protection is always active when the battery switch is enabled, and the protection has a deglitch time that depends on the ocp_res setting as described below. if ocp_res = ? 0 ? (blanking mode), the device will wait t ibus_ocp_blank before disabling the battery switch within t off_fet and setting chg_en to ? 0 ? . when the battery switch is disabled, ibus_ocp_flt is set to ? 1 ? . if during the t ibus_ocp_blank duration a short circuit protection scenario occurs, then the device will follow the behavior as listed in short circuit protection (scp). once the battery switch is disabled, chg_en is set to ? 0 ? and host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. figure 11. ibus ocp and scp vout ibus t ibus_ocp_blank t off_fet ibus_ocp i scp vout ibus t off_fet ibus_ocp i scp t ibus_ocp_blank time starts here t scp
22 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) if ocp_res = ? 1 ? (hiccup mode), the device will turn off the battery switch within t ibus_ocp and will attempt to turn on the battery switch every t ibus_ocp_hp , up to seven times before latching off the battery switch. upon latching off after the seventh try, ibus_ocp_flt is set to ? 1 ? . once the battery switch is latched off, chg_en is set to ? 0 ? and host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. figure 12. ibus ocp in hiccup mode vbus over-voltage protection (vbus_ovp) monitors the voltage on vbus. vbus_ovp protection is always active when the device voltage is above at least one present level (vbus or vout), and the protection has a selectable deglitch time set by vbus_ovp_dly. when vbus_ovp threshold is reached, the battery switch is turned off in t vbus_ovp and latched off. if the vbus_ovp or ibus_ocp value written to the register is greater than the max defined value for the register, then the corresponding register will be set to the highest defined value. if a threshold has been crossed (ibus_ocp or vbus_ovp), the appropriate bit in the event_1 register is updated (set to ? 1 ? if threshold is crossed, ? 0 ? if threshold is not crossed). if the event_1_mask bit is not set to ? 1 ? for the corresponding bit in the event_1 register, then int will assert low to alert the host of a fault. vout ibus t off_fet i scp ibus_ocp t ibus_ocp t ibus_ocp_hp t off_fet t ibus_hp_rst hiccup count = 1 hiccup count = 2 hiccup count = 1 hiccup count resets t ibus_ocp t ibus_ocp t off_fet
23 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.5.5 ibat and vbat protection the device monitors current through the battery by monitoring the voltage across the external, series battery sense resistor. the differential voltage of this sense resistor is measured on srp and srn. a 10-m series resistor is recommended for battery current monitoring. a lower resistor value can be used, but it will result in lower measurement accuracy. a higher resistor value can be used, but it will result in decreased charging efficiency. when the ibat_reg threshold is reached, the device will go into ldo mode to regulate the battery current at the ibat_reg threshold. see ldo mode section for more details about the device operation during ldo mode. if the ibat_ocp threshold is reached and ibat_ocp protection has been enabled, the battery switch will be disabled within t off_fet after a deglitch time of t ibat_ocp and chg_en is set to ? 0 ? . host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. the device monitors battery voltage by measuring the differential voltage on batp and batn pins. when the vbat_reg threshold is reached, the device will go into ldo mode to regulate the battery voltage at the vbat_reg threshold. see ldo mode section for more details about the device operation during ldo mode. if the vbat_ovp threshold is reached and vbat_ovp protection is enabled, the battery switch will be disabled within t off_fet after a deglitch time of t vbat_ovp and chg_en is set to ? 0 ? . host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. if the vbat_reg or ibat_reg value written to the register is greater than the max defined value for the register, then the corresponding register will be set to the highest defined value. if a threshold has been reached (ibat_reg, vbat_reg, ibat_ocp or vbat_ovp), the appropriate bit in the event_x register is updated (set to ? 1 ? if threshold is crossed, ? 0 ? if threshold is not crossed). if the event_x_mask bit is not set to ? 1 ? for the corresponding bit in the event_x register, then int will assert low to alert the host of a fault. 8.3.5.6 vout protection the device monitors voltage on vout when the device has a valid power supply. when the vout_reg threshold is reached, the device will go into ldo mode to regulate the vout voltage at the vout_reg threshold. see ldo mode section for more details about the device operation during ldo mode. if the vout_ovp threshold is reached and vout_ovp protection is enabled, the battery switch will be disabled within t off_fet after a deglitch time of t vout_ovp and chg_en is set to ? 0 ? . host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. if the vout_reg value written to the register is greater than the max defined value for the register, then vout_reg will be set to the highest defined value for the register. if a threshold has been reached (vout_reg or vout_ovp), the appropriate bit in the event_1 register is updated (set to ? 1 ? if threshold is crossed, ? 0 ? if threshold is not crossed). if the event_x_mask bit is not set to ? 1 ? for the corresponding bit in the event_x register, then int will assert low to alert the host of a fault.
24 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.5.7 vdrop protection vdrop is the voltage difference from vbus to vout and can be used to monitor the health of mosfet and power loss of the device. there are two vdrop thresholds, vdrop alarm (vdrop_alm) and vdrop fault (vdrop_flt). vdrop_alm is an indicator (via i 2 c register bit and int) to alert the host that the voltage differential between vbus and vout is higher than normal, and that the host to should take action to reduce this drop. vdrop_ovp is a fault threshold that results in the battery switch being disabled within t off_fet after a deglitch time of t vdrop_ovp and chg_en set to ? 0 ? when vdrop_ovp protection is enabled. host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. if the vdrop_ovp or vdrop_alm value written to the register is greater than the max defined value for the register, then the corresponding register will be set to the highest defined value. if a threshold has been reached (vdrop_alm or vdrop_ovp), the appropriate bit in the event_1 register is updated (set to ? 1 ? if threshold is crossed, ? 0 ? if threshold is not crossed). if the event_x_mask bit is not set to ? 1 ? for the corresponding bit in the event_x register, then int will assert low to alert the host of a fault. vdrop_alm does not affect the state of the battery switch and only causes int to assert low when the threshold is crossed. vdrop_ovp does turn off the battery switch and causes int to assert low if this threshold is crossed. therefore, if vdrop_alm threshold is set higher than the vdrop_ovp threshold accidentally (user error), then vdrop_alm functionality is never triggered since vdrop_ovp threshold will turn off the battery switch and assert int low. note the threshold of vdrop_ovp and vdrop_alm is around 13 mv lower than the actual setting when vdrop adc is enabled. 8.3.5.8 vbus temperature (ts_bus_flt) and battery temperature (ts_bat_flt) tbus_otp and tbat_otp protection is active whenever the device has a valid power supply. the purpose of vbus temperature is to have connector temperature monitor to improve user experience. ts_bus and ts_bat both rely on a resistor divider that has an external pull-up voltage. internally, the ts_bus and ts_bat pins are clamped to 2.42 v. place a negative coefficient thermistor in parallel to the low-side resistor. a fault on the ts_bus and ts_bat pin is triggered on the falling edge of the voltage threshold (signifying a ? hot ? temperature). if the tbus_otp or tbat_otp threshold is reached, the battery switch will be disabled within t off_fet after a deglitch time of t ts_otp and chg_en is set to ? 0 ? . host intervention is required to set chg_en to ? 1 ? to enable the battery switch again. if the ts_bus_flt or ts_bat_flt value written to the register is greater than the max defined value for the register, then the corresponding register will be set to the highest defined value. for ts_bus_flt and ts_bat_flt, if a threshold has been crossed, the appropriate bit in the event_x register is updated (set to ? 1 ? if threshold is crossed, ? 0 ? if threshold is not crossed). if the event_x_mask bit is not set to ? 1 ? for the corresponding bit in the event_1 register, then int will toggle to alert the host of a fault. note ts_bus_flt will not trip when ts_bus adc is enabled.
25 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.6 i 2 c serial interface the device uses i 2 c compatible interface for flexible charging parameter programming and instantaneous device status reporting. i 2 c communication to the device is available as long as v vusb > vusb uvlo or v vbus > vbus uvlo or v vout > vout uvlo . i 2 c ? is a bi-directional 2-wire serial interface developed by philips semiconductor (now nxp semiconductors). only two bus lines are required, a serial data line (sda) and a serial clock line (scl). devices can be considered as masters or slaves when performing data transfers. a master is the device which initiates a data transfer on the bus and generates the clock signals to permit that transfer. at that time, any device addressed is considered a slave. the device operates as a slave device with address set by the addr pin. the device receives control inputs from the master device like micro controller or a digital signal processor through reg00-reg29 and reg40. register read between reg29 and reg39 beyond reg40 returns 0xff. the i 2 c interface supports standard mode (up to 100 kbit/s), fast mode (up to 400 kbit/s), and fast mode plus (up to 1 mbit/s). connect the sda and scl pins to the positive supply voltage via a current source or pull-up resistor. when the bus is free, both lines are high. the sda and scl pins are open drain. the device supports 7-bit addressing. the 8th bit will change depending upon the command (read or write) that is issued. the device ? s 7-bit address is defined as shown in the image below. figure 13. slave address 8.3.6.1 data validity the data on the sda line must be stable during the high period of the clock. the high or low state of the data line can only change when the clock signal on the scl line is low. one clock pulse is generated for each data bit transferred. figure 14. bit transfer on the i 2 c bus 1 1 0 0 1 0 1 r/w slave address sda scl data line stable; data valid change of data allowed
26 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.6.2 start and stop conditions all transactions begin with a start (s) and can be terminated by a stop (p). a high to low transition on the sda line while scl is high defines a start condition. a low to high transition on the sda line when the scl is high defines a stop condition. start and stop conditions are always generated by the master. the bus is considered busy after the start condition, and free after the stop condition. figure 15. start and stop conditions 8.3.6.3 byte format every byte on the sda line must be 8 bits long. the number of bytes to be transmitted per transfer is unrestricted. each byte has to be followed by an acknowledge bit. data is transferred with the most significant bit (msb) first. if a slave cannot receive or transmit another complete byte of data until it has performed some other function, it can hold the clock line scl low to force the master into a wait state (clock stretching). data transfer then continues when the slave is ready for another byte of data and release the clock line scl. figure 16. data transfer on the i 2 c bus 8.3.6.4 acknowledge (ack) and not acknowledge (nack) the acknowledge takes place after every byte. the acknowledge bit allows the receiver to signal the transmitter that the byte was successfully received and another byte may be sent. all clock pulses, including the acknowledge 9th clock pulse, are generated by the master. the transmitter releases the sda line during the acknowledge clock pulse so the receiver can pull the sda line low and it remains stable low during the high period of this clock pulse. when sda remains high during the ninth clock pulse, this is the not acknowledge signal. the master can then generate either a stop to abort the transfer or a repeated start to start a new transfer. scl sda start or repeated start s or sr 1 2 7 8 9 msb ack acknowledgement signal from slave 1 2 8 9 ack acknowledgement signal from receiver stop or repeated start p or sr sda scl start (s) stop (p) sda scl
27 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated feature description (continued) 8.3.6.5 slave address and data direction bit after the start, a slave address is sent. this address is 7 bits long followed by the eighth bit as a data direction bit (bit r/w). a zero indicates a transmission (write) and a one indicates a request for data (read). figure 17. complete data transfer figure 18. single read if the register address is not defined, the charger device send back nack and go back to the idle state. 8.3.6.6 multi-read and multi-write the charger device supports multi-read and multi-write on reg00 through reg08. figure 19. multi-read event_1, event_2, and event_3 keep all the information from last read until the host issues a new read. for example, if vbus_ovp fault occurs but recovers later, the fault register event_1 reports the fault when it is read the first time, but returns to normal when it is read the second time. in order to get the fault information at present, the host has to read event_1, event_2, and event_3 for the second time. 1 7 1 1 1 8 8 1 slave address s ack 0 reg address ack data at address ack 8 1 1 p data at addr+n nck 8 data at address +1 1 ack 1 7 1 1 slave address s ack 1 1 7 1 1 1 8 7 1 11 slave address s ack 0 reg address ack slave address ack s 1 8 1 1 p data nck scl sda start s 1-7 8 9 ack 1-7 8 9 ack 1-7 8 9 stop p address r/w data ack data
28 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.4 device functional modes the device is a host controlled device. after power-on-reset, all the registers are in the default settings. all the device parameters can be programmed by the host. writing 1 to reg 06 [0] will reset all registers to default setting. when watchdog timer expires, charge enable bit (reg06 [4]) and adc enable bit (reg07 [3]) will be reset to default settings. to prevent watchdog timer expiring, the host has to read or write any register before the watchdog timer expires, or disable watchdog timer by setting reg06 [3:2] = 00. figure 20. operation mode por watchdog timer expired reset registers i2c interface enabled i2c write? start watchdog timer host programs registers reset reg 06 bit[0] watchdog timer expired? reset watchdog timer reset reg 06 bit [4] reg 07 bit [3] y y n y
29 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5 i 2 c register maps 8.5.1 i 2 c register summary table table 2. i 2 c register summary table i 2 c address r/w register name description por state 0x00 r device_info device rev and device id 0x03 0x01 r/w event_1_mask masks int toggle of events in event_1 0x00 0x02 r/w event_2_mask masks int toggle of events in event_2 0x00 0x03 r event_1 first event register 0x00 0x04 r event_2 second event register 0x00 0x05 r/w event_1_en enables/disables protection in event_1 register 0xfe 0x06 r/w control settings for battery switch, watchdog, reset, and rcp threshold 0x2c 0x07 r/w adc_ctrl contains adc control bits such as enable/disable, rate, and number of samples to take 0x87 0x08 r/w adc_mask controls which parameters the adc converts ? first set 0xff 0x09 r/w protection deglitch setting and vbus ocp threshold 0xa0 0x0a r/w vbus_ovp sets vbus ovp threshold 5.49 v 0x0b r/w vout_reg sets vout voltage regulation threshold 4.4 v 0x0c r/w vdrop_ovp sets the vdrop ovp threshold 300 mv 0x0d r/w vdrop_alm sets the vdrop alarm threshold 100 mv 0x0e r/w vbat_reg battery (batp ? batn) regulation threshold 4.3 v 0x0f r/w ibat_reg sets battery current regulation threshold 2 a 0x10 r/w ibus_reg sets vbus reg threshold 5 a 0x11 r/w ts_bus_flt sets vbus temperature threshold 0.6 v 0x12 r/w ts_bat_flt sets battery temperature threshold 0.7 v 0x13 r vbus_adc adc output of vbus voltage measurement 0x00 0x14 r 0x00 0x15 r ibus_adc adc output of vbus current measurement 0x00 0x16 r 0x00 0x17 r vout_adc adc output of vout voltage measurement 0x00 0x18 r 0x00 0x19 r vdrop_adc adc output of (vbus ? vout) voltage measurement 0x00 0x1a r 0x00 0x1b r vbat_adc adc output of battery voltage measurement 0x00 0x1c r 0x00 0x1d r ibat_adc adc output of battery current measurement 0x00 0x1e r 0x00 0x1f r tbus_adc adc output of ts_bus voltage 0x00 0x20 r 0x00 0x21 r tbat_adc adc output of ts_bat voltage 0x00 0x22 r 0x00 0x23 r die_temp_adc adc output of the die temperature 0x00 0x24 r/w event_3_en enables/disables protection in event_3 register 0x04 0x25 r/w event_3_mask masks int toggle of events in event_3 0x00 0x26 r/w evnet_3 third event register 0x00 0x27 r vusb_adc adc output of vusb voltage 0x00 0x28 r 0x00 0x29 r/w control_2 vusb settings 0x6e 0x40 r/w tdie_temp_flt setting die over temperature fault threshold 0x03
30 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.2 reg00 (device_info) figure 21. reg00 (device_info) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 1 r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 3. reg00 (device_info) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 6 reserved r n/a n/a n/a reserved bit. always reads 0. 5 device_rev[2] r n/a n/a n/a device revision. 4 device_rev[1] r n/a n/a n/a device revision. 3 device_rev[0] r n/a n/a n/a device revision. 2 device_id[2] r n/a n/a n/a device id 011 1 device_id[1] r n/a n/a n/a 0 device_id[0] r n/a n/a n/a
31 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.3 reg01 (event_1_mask) figure 22. reg01 (event_1_mask) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r/w r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 4. reg01 (event_1_mask) bit field type reset description reg_rst watchdog en 7 vbus_ovp_mask r/w y n y vbus over voltage fault mask 0 ? no mask. int will assert low when vbus_ovp_flt bit is set (default) 1 ? vbus_ovp_flt is mask. int will not assert low when vbus_ovp_flt is set. 6 ldo_active_mask r/w y n y ldo active bit mask 0 ? no mask. int will assert low when ldo_active bit is set (default) 1 ? ldo_active is mask. int will not assert low when ldo_active bit is set. 5 ldo_active_mask r/w y n y ldo active bit mask 0 ? no mask. int will assert low when ldo_active bit is set (default) 1 ? ldo_active is mask. int will not assert low when ldo_active is set. 4 ldo_active_mask r/w y n y ldo active bit mask 0 ? no mask. int will assert low when ldo_active bit is set (default) 1 ? ldo_active is mask. int will not assert low when ldo_active is set. 3 ldo_active_mask r/w y n y ldo active bit mask 0 ? no mask. int will assert low when ldo_active bit is set (default) 1 ? ldo_active is mask. int will not assert low when ldo_active is set. 2 ts_bus_flt_mask r/w y n y vbus over temperature fault mask 0 ? no mask. int will assert low when ts_bus_flt bit is set (default) 1 ? ts_bus_flt is mask. int will not assert low when ts_bus_flt is set. 1 ts_bat_flt_mask r/w y n y vbus over temperature fault mask 0 ? no mask. int will assert low when ts_bat_flt bit is set (default) 1 ? ts_bat_flt is mask. int will not assert low when ts_bat_flt is set. 0 ibus_rev_mask r/w y n y ibus reverse current fault mask 0 ? no mask. int will assert low when ibus_rev bit is set (default) 1 ? ibus_rev is mask. int will not assert low when ibus_rev is set.
32 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.4 reg02 (event_2_mask) figure 23. reg02 (event_2_mask) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r/w r/w r/w r/w r/w r r/w legend: r/w = read/write; r = read only; -n = value after reset table 5. reg02 (event_2_mask) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 6 adc_done_mask r/w y n y adc_done bit mask 0 ? no mask. int will assert low when adc_done bit is set (default) 1 ? adc_done is mask. int will not assert low when adc_done bit is set. 5 vdrop_alm_mask r/w y n y vdrop_alm event mask 0 ? no mask. int will assert low when vdrop_alm bit is set (default) 1 ? vdrop_alm is mask. int will not assert low when vdrop_alm bit is set. 4 vdrop_ovp_mask r/w y n y vdrop_ovp event mask 0 ? no mask. int will assert low when vdrop_ovp bit is set (default) 1 ? vdrop_ovp is mask. int will not assert low when vdrop_ovp is set. 3 vbus_insert_mas k r/w y n y vbus_insert mask 0 ? no mask. int will assert low when vbus_insert bit is set (default) 1 ? vbus_insert is mask. int will not assert low when vbus_insert is set. 2 bat_insert_mask r/w y n y bat_insert mask 0 ? no mask. int will assert low when bat_insert bit is set (default) 1 ? bat_insert is mask. int will not assert low when bat_insert is set. 1 reserved r n/a n/a n/a reserved bit. always reads 0. 0 ibus_ocp_mask r/w y n y ibus over current fault mask 0 ? no mask. int will assert low when ibus_ocp bit is set (default) 1 ? ibus_ocp is mask. int will not assert low when ibus_ocp is set.
33 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.5 reg03 (event_1) figure 24. reg03 (event_1) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 6. 6.4.5 reg03 (event_1) bit field type reset description reg_rst watchdog en 7 vbus_ovp_flt r y n y vbus over voltage fault. this bit is set when vbus voltage exceeds the limit set in vbus_ovp register 0 ? no fault (default) 1 ? vbus ovp fault 6 ldo_active r y n y indicates if the device is in ldo mode 0 ? not in ldo mode (default) 1 ? in ldo mode 5 ldo_active r y n y indicates if the device is in ldo mode 0 ? not in ldo mode (default) 1 ? in ldo mode 4 ldo_active r y n y indicates if the device is in ldo mode 0 ? not in ldo mode (default) 1 ? in ldo mode 3 ldo_active r y n y indicates if the device is in ldo mode 0 ? not in ldo mode (default) 1 ? in ldo mode 2 ts_bus_flt r y n y vbus over temperature fault. this bit is set when ts_bus voltage falls below the limit set in ts_bus_register. battery switch is disabled. 0 ? no fault (default) 1 ? vbus over temperature fault 1 ts_bat_flt r y n y battery over temperature fault. this bit is set when ts_bat voltage falls below the limit set in ts_bat_register. battery switch is disabled. 0 ? no fault (default) 1 ? vbat over temperature fault 0 ibus_irev_flt r y n y ibus reverse current fault. this bit is set when current from vout to vbus is detected. battery switch is disabled. 0 ? no fault (default) 1 ? ibus reverse current fault
34 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.6 reg04 (event_2) figure 25. reg04 (event_2) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 7. reg04 (event_2) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 6 adc_done. r y n y indicates if adc conversion is complete for the required parameters in 1-shot mode only. this bit will change to '0' when an adc conversion is is requested in 1-shot mode, and it will change back to '1' when the conversion is complete. during continuous conversion mode, this bit will be '0'. 0 ? conversion not complete (default) 1 ? conversion complete 5 vdrop_alm r y n y indicates if vdrop_alm threshold is reached 0 ? no fault (default) 1 ? vdrop_alm fault 4 vdrop_ovp_flt r y n y indicates if vdrop_ovp threshold is reached. battery switch is disabled. 0 ? no fault (default) 1 ? vdrop_ovp fault 3 vbus_insert r y n y indicates if vbus is detected. \int toggles when vbus is inserted but does not toggle when vbus is removed. 0 ? vbus not inserted (default) 1 ? vbus inserted 2 bat_insert r y n y indicates if battery is detected. \int toggles when battery is inserted but does not toggle when battery is removed. 0 ? battery not inserted (default) 1 ? battery inserted 1 tshut_flt r/w y n y ic thermal shutdown indictator. battery switch is disabled. 0 ? no fault (default) 1 ? ic thermal shutdown fault 0 ibus_ocp_flt r/w y n y ibus over current fault. this bit is set when ibus exceeds ibus_ocp register. battery switch is disabled. 0 ? no fault (default) 1 ? ibus over current fault
35 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.7 reg05 (event_1_en) figure 26. reg05 (event_1_en) 7 6 5 4 3 2 1 0 1 1 1 1 1 1 1 0 r/w r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 8. reg05 (event_1_en) bit field type reset description reg_rst watchdog en 7 vbus_ovp_en r/w y n y enables vbus_ovp protection 0 ? disable vbus_ovp protection 1 ? enable vbus_ovp protection (default) 6 ibus_reg_en r/w y n y enable ibus regulation 0 ? disable ibus regulation 1 ? enable ibus regulation (default) 5 vbat_reg_en r/w y n y enable vbat regulation 0 ? disable vbat regulation 1 ? enable vbat regulation (default) 4 ibat_reg_en r/w y n y enable ibat regulation 0 ? disable ibat regulation 1 ? enable ibat regulation (default) 3 vout_reg_en r/w y n y enable vout regulation 0 ? disable vout regulation 1 ? enable vout regulation (default) 2 ts_bus_flt_en r/w y n y enable ts_bus protection 0 ? disable ts_bus protection 1 ? enable ts_bus protection (default) 1 ts_bat_flt_en r/w y n y enable ts_bat protection 0 ? disable ts_bat protection 1 ? enable ts_bat protection (default) 0 vbus_pd_en r/w y n y enable the vbus pull-down resistor (rvbus_pd) 0 ? disable rvbus_pd (default) 1 ? enable rvbus_pd
36 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.8 reg06 (control) figure 27. reg06 (control) 7 6 5 4 3 2 1 0 0 0 1 0 0 1 0 0 r/w r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 9. reg06 (control) bit field type reset description reg_rst watchdog en 7 vdrop_ovp_en r/w y n y enables vdrop_ovp protection 0 ? disable vdrop_ovp protection (default) 1 ? enable vdrop_ovp protection 6 vdrop_alm_en r/w y n y enables vdrop_alm protection 0 ? disable vdrop_alm protection (default) 1 ? enable vdrop_alm protection 5 sense_r r/w y n y select the sense resistor value between srp and srn 0 ? 5 m 1 ? 10 m (default) 4 chg_en r/w y y y software bit for charge enable. this enables the battery switch. this bit will set to '0' if any fault causes the battery switch to be disabled. 0 ? charge disabled (default) 1 ? charge enabled 3 watchdog[1] r/w y n y watchdog timer setting 00 ? disable watchdog timer 01 ? 0.5 s 10 ? 1.0 s (default) 11 ? 2 s 2 watchdog[0] r/w y n y 1 rcp_set r/w y n y reverse current protection (rcp) threshold setting 0 ? rcp set to 0 a (default) 1 ? rcp set to -3 a 0 reg_rst r/w y n y register reset 0 ? no reset (default) 1 ? reset all registers to default values
37 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.9 reg07 (adc_control) figure 28. reg07 (adc_control) 7 6 5 4 3 2 1 0 1 0 0 0 0 1 1 1 r/w r r r r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 10. reg07 (adc_control) bit field type reset description reg_rst watchdog en 7 tdie_adc_en r/w y n y enable/ disable conversion of die junction temperature 0 ? disable conversion 1 ? enabled conversion (default) 6 reserved r y n y reserved bit. always read 0. 5 reserved r y n y reserved bit. always read 0. 4 reserved r y n y reserved bit. always read 0. 3 adc_en r/w y y y enable/ disable adc 0 ? disable adc (default) 1 ? enable adc 2 adc_rate r/w y n y set adc conversion rate 0 ? 1-shot conversion 1 ? continuous conversion (default) 1 adc_avg_en r/w y n y enable/disable adc measurement averaging 0 ? disable averaging, instantaneous measurement 1 ? enable averaging (default) 0 adc_samples r/w y n y set the number of samples to be taken for an adc conversion 0 ? 8 samples taken for averaging 1 ? 16 samples taken for averaging (default)
38 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.10 reg08 (adc_en) figure 29. reg08 (adc_en) 7 6 5 4 3 2 1 0 1 1 1 1 1 1 1 1 r/w r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 11. reg08 (adc_en) bit field type reset description reg_rst watchdog en 7 vbus_adc_en r/w y n y enable/ disable conversion of vbus voltage 0 ? disable conversion 1 ? enabled conversion (default) 6 ibus_adc_en r/w y n y enable/ disable conversion of ibus current 0 ? disable conversion 1 ? enabled conversion (default) 5 vout_adc_en r/w y n y enable/ disable conversion of vout voltage 0 ? disable conversion 1 ? enabled conversion (default) 4 vdrop_adc_en r/w y n y enable/ disable conversion of vdrop voltage 0 ? disable conversion 1 ? enabled conversion (default) 3 vbat_adc_en r/w y n y enable/ disable conversion of vbat voltage 0 ? disable conversion 1 ? enabled conversion (default) 2 ibat_adc_en r/w y n y enable/ disable conversion of ibat current 0 ? disable conversion 1 ? enabled conversion (default) 1 ts_bus_adc_en r/w y n y enable/ disable conversion of ts_bus voltage 0 ? disable conversion 1 ? enabled conversion (default) 0 ts_bat_adc_en r/w y n y enable/ disable conversion of ts_bat voltage 0 ? disable conversion 1 ? enabled conversion (default)
39 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.11 reg09 (protection) figure 30. reg09 (protection) 7 6 5 4 3 2 1 0 1 0 1 0 0 0 0 0 r/w r/w r/w r/w r r r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 12. reg09 bit field type reset description reg_rst watchdog en 7 ibus_ocp[3] r/w y n y 4 a vbus input overcurrent threshold offset: none range: 0 a to 7.5 a default: 5 a (1010) 6 ibus_ocp[2] r/w y n y 2 a 5 ibus_ocp[1] r/w y n y 1 a 4 ibus_ocp[0] r/w y n y 0.5 a 3 reserved r y n y reserved bit. always read 0. 2 reserved r y n y reserved bit. always read 0. 1 ocp_res r/w y n y controls the response of the ocp event or ibus 0 ? blanking mode; the device will wait 128 s before the battery switch is disabled and latched off (default) 1 ? hiccup mode; battery switch is disabled instantaneously, and the device will attampt to turn on the battery switch every 100 ms, up to 7 times before latching off. 0 vbus_ovp_dly r/w y n y set vbus fault deglitch time 0 ? 8 s deglitch time (default) 1 ? 128 s deglitch time 8.5.12 reg0a (vbus_ovp) figure 31. reg0a (vbus_ovp) 7 6 5 4 3 2 1 0 0 0 1 0 1 0 1 1 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 13. reg0a (vbus_ovp) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 vbus_ovp[6] r/w y n y 1920 mv vbus over voltage threshold offset: 4.2 v range: 4.2 v to 6.51 v default: 5.49 v (00101011) 5 vbus_ovp[5] r/w y n y 960 mv 4 vbus_ovp[4] r/w y n y 480 mv 3 vbus_ovp[3] r/w y n y 240 mv 2 vbus_ovp[2] r/w y n y 120 mv 1 vbus_ovp[1] r/w y n y 60 mv 0 vbus_ovp[0] r/w y n y 30 mv
40 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.13 reg0b (vout_reg) figure 32. reg0b (vout_reg) 7 6 5 4 3 2 1 0 0 0 0 1 0 0 0 0 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 14. reg0b (vout_reg) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 vout_ovp[5] r/w y n y 800 mv vout regulation threshold offset: 4.2 v range: 4.2 v to 4.975 v default: 4.4 v (00010000) 5 vout_ovp[4] r/w y n y 400 mv 4 vbus_ovp[3] r/w y n y 200 mv 3 vbus_ovp[2] r/w y n y 100 mv 2 vbus_ovp[1] r/w y n y 50 mv 1 vbus_ovp[0] r/w y n y 25 mv 0 reserved r/w y n y reserved bit. always read 0.
41 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.14 reg0c (vdrop_ovp) figure 33. reg0c (vdrop_ovp) 7 6 5 4 3 2 1 0 0 0 1 1 1 1 0 0 r/w r/w r/w r/w r/w r/w r/w r legend: r/w = read/write; r = read only; -n = value after reset table 15. reg0c (vdrop_ovp) bit field type reset description reg_rst watchdog en 7 vdrop_ovp[6] r/w y n y 640 mv vdrop ovp threshold offset: none range: 0 mv to 1000 mv default: 300 mv (00111100) 6 vdrop_ovp[5] r/w y n y 320 mv 5 vdrop_ovp[4] r/w y n y 160 mv 4 vdrop_ovp[3] r/w y n y 80 mv 3 vdrop_ovp[2] r/w y n y 40 mv 2 vdrop_ovp[1] r/w y n y 20 mv 1 vdrop_ovp[1] r/w y n y 10 mv 0 reserved r y n y reserved bit. always read 0. 8.5.15 reg0d (vdrop_alm) figure 34. reg0d (vdrop_alm) 7 6 5 4 3 2 1 0 0 0 0 1 0 1 0 0 r/w r/w r/w r/w r/w r/w r/w r legend: r/w = read/write; r = read only; -n = value after reset table 16. reg0d (vdrop_alm) bit field type reset description reg_rst watchdog en 7 vdrop_alm[6] r/w y n y 640 mv vdrop alm threshold offset: none range: 0 mv to 1000 mv default: 100 mv (00010100) 6 vdrop_alm[5] r/w y n y 320 mv 5 vdrop_alm[4] r/w y n y 160 mv 4 vdrop_alm[3] r/w y n y 80 mv 3 vdrop_alm[2] r/w y n y 40 mv 2 vdrop_alm[1] r/w y n y 20 mv 1 vdrop_alm[1] r/w y n y 10 mv 0 reserved r y n y reserved bit. always read 0.
42 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.16 reg0e (vbat_reg) figure 35. reg0e (vbat_reg) 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 0 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 17. reg0e (vbat_reg) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 vbat_reg[6] r/w y n y 800 mv battery voltage regulation threshold offset: 4.2 v range: 4.2 v to 4.975 v default: 4.3 v (00001000) 5 vbat_reg[5] r/w y n y 400 mv 4 vbat_reg[4] r/w y n y 200 mv 3 vbat_reg[3] r/w y n y 100 mv 2 vbat_reg[2] r/w y n y 50 mv 1 vbat_reg[1] r/w y n y 25 mv 0 vbat_reg[0] r/w y n y 12.5 mv 8.5.17 reg0f (ibat_reg) figure 36. reg0f (ibat_reg) 7 6 5 4 3 2 1 0 0 0 1 0 1 0 0 0 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 18. reg0f (ibat_reg) bit field type reset description reg_r st watchd og en 7 reserved r y n y reserved bit. always read 0. 6 ibat_reg[6] r/w y n y 3200 ma battery current regulation threshold offset: 0 a range: 0 a to 6.35 a default: 2 a (00101000) 5 ibat_reg[5] r/w y n y 1600 ma 4 ibat_reg[4] r/w y n y 800 ma 3 ibat_reg[3] r/w y n y 400 ma 2 ibat_reg[2] r/w y n y 200 ma 1 ibat_reg[1] r/w y n y 100 ma 0 ibat_reg[0] r/w y n y 50 ma
43 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.18 reg10 (ibus_reg) figure 37. reg10 (ibus_reg) 7 6 5 4 3 2 1 0 1 1 1 0 0 1 0 0 r r/w r/w r/w r/w r/w r/w r legend: r/w = read/write; r = read only; -n = value after reset table 19. reg10 (ibus_reg) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 ibus_reg[5] r/w y n y 3200 ma battery current regulation threshold offset: 0 a range: 0 a to 6.3 a default: 5 a (01100100) 5 ibus_reg[4] r/w y n y 1600 ma 4 ibus_reg[3] r/w y n y 800 ma 3 ibus_reg[2] r/w y n y 400 ma 2 ibus_reg[1] r/w y n y 200 ma 1 ibus_reg[0] r/w y n y 100 ma 0 reserved r y n y reserved bit. always read 0. 8.5.19 reg11 (ts_bus_flt) figure 38. reg11 (ts_bus_flt) 7 6 5 4 3 2 1 0 0 0 0 1 1 0 0 0 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 20. reg11 (ts_bus_flt) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 ts_bus_flt[6] r/w y n y 1600 ma ts_bus voltage threshold offset: 0 v range: 0 v to 1.4 v default: 0.6 v (00011000) 5 ts_bus_flt[5] r/w y n y 800 ma 4 ts_bus_flt[4] r/w y n y 400 ma 3 ts_bus_flt[3] r/w y n y 200 ma 2 ts_bus_flt[2] r/w y n y 100 ma 1 ts_bus_flt[1] r/w y n y 50 ma 0 ts_bus_flt[0] r/w y n y 25 ma
44 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.20 reg12 (ts_bat_flt) figure 39. reg12 (ts_bat_flt) 7 6 5 4 3 2 1 0 0 0 0 1 1 1 0 0 r r/w r/w r/w r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 21. reg12 (ts_bat_flt) bit field type reset description reg_rst watchdog en 7 reserved r y n y reserved bit. always read 0. 6 ts_bat_flt[6] r/w y n y 1600 ma ts_bat voltage threshold offset: 0 v range: 0 v to 1.4 v default: 0.7 v (00011100) 5 ts_bat_flt[5] r/w y n y 800 ma 4 ts_bat_flt[4] r/w y n y 400 ma 3 ts_bat_flt[3] r/w y n y 200 ma 2 ts_bat_flt[2] r/w y n y 100 ma 1 ts_bat_flt[1] r/w y n y 50 ma 0 ts_bat_flt[0] r/w y n y 25 ma 8.5.21 reg 13 and reg 14 (vbus_adc) figure 40. reg 13 and reg 14 (vbus_adc) reg13 reg14 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 22. reg 13 and reg 14 (vbus_adc) register bit field type reset description reg_rst watchdog en reg13 7 vbus_pol r y n y indicates polarity of vbus voltage. always positive. 0 - positive voltage 1 - negative voltage 6 vbus_adc[14] r y n y 16384 mv voltage representation of adc conversion of vbus voltage. range: 0 v, and 2.048 v to 6.140 v default: 0 v (0000000000000000) if vbus < 0.3 v, vbus_adc = 0.3 v 5 vbus_adc[13] r y n y 8192 mv 4 vbus_adc[12] r y n y 4096 mv 3 vbus_adc[11] r y n y 2048 mv 2 vbus_adc[10] r y n y 1024 mv 1 vbus_adc[9] r y n y 512 mv 0 vbus_adc[8] r y n y 256 mv reg14 7 vbus_adc[7] r y n y 128 mv 6 vbus_adc[6] r y n y 64 mv 5 vbus_adc[5] r y n y 32 mv 4 vbus_adc[4] r y n y 16 mv 3 vbus_adc[3] r y n y 8 mv 2 vbus_adc[2] r y n y 4 mv 1 vbus_adc[1] r y n y 2 mv 0 vbus_adc[0] r y n y 1 mv
45 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.22 reg15 and reg16 (ibus_adc) figure 41. reg15 and reg16 (ibus_adc) reg15 reg16 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 23. reg15 and reg16 (ibus_adc) register bit field type reset description reg_rst watchdog en reg15 7 ibus_pol r y n y indicates polarity of ibus current. always positive. 0 - positive current 1 - negative current 6 ibus_adc[14] r y n y 16384 ma current representation of adc conversion of vbus current. range: 0 a to 7.5 a default: 0 a (0000000000000000) 5 ibus_adc[13] r y n y 8192 ma 4 ibus_adc[12] r y n y 4096 ma 3 ibus_adc[11] r y n y 2048 ma 2 ibus_adc[10] r y n y 1024 ma 1 ibus_adc[9] r y n y 512 ma 0 ibus_adc[8] r y n y 256 ma reg16 7 ibus_adc[7] r y n y 128 ma 6 ibus_adc[6] r y n y 64 ma 5 ibus_adc[5] r y n y 32 ma 4 ibus_adc[4] r y n y 16 ma 3 ibus_adc[3] r y n y 8 ma 2 ibus_adc[2] r y n y 4 ma 1 ibus_adc[1] r y n y 2 ma 0 ibus_adc[0] r y n y 1 ma
46 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.23 reg17 and reg18 (vout_adc) figure 42. reg17 and reg18 (vout_adc) reg17 reg18 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 24. reg17 and reg18 (vout_adc) register bit field type reset description reg_rst watchdog en reg17 7 vout_pol r y n y indicates polarity of vdrop voltage. always positive. 0 - positive voltage 1 - negative voltage 6 vout_adc[14] r y n y 16384 mv voltage representation of adc conversion of vdrop voltage. range: 2.048 v to 6.140 v default: 0 v (0000000000000000) 5 vout_adc[13] r y n y 8192 mv 4 vout_adc[12] r y n y 4096 mv 3 vout_adc[11] r y n y 2048 mv 2 vout_adc[10] r y n y 1024 mv 1 vout_adc[9] r y n y 512 mv 0 vout_adc[8] r y n y 256 mv reg18 7 vout_adc[7] r y n y 128 mv 6 vout_adc[6] r y n y 64 mv 5 vout_adc[5] r y n y 32 mv 4 vout_adc[4] r y n y 16 mv 3 vout_adc[3] r y n y 8 mv 2 vout_adc[2] r y n y 4 mv 1 vout_adc[1] r y n y 2 mv 0 vout_adc[0] r y n y 1 mv
47 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.24 reg19 and reg1a (vdrop_adc) figure 43. reg19 and reg1a (vdrop_adc) reg19 reg1a 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 25. reg19 and reg1a (vdrop_adc) register bit field type reset description reg_rst watchdog en reg19 7 vdrop_pol r y n y indicates polarity of vdrop voltage. always positive. 0 - positive voltage 1 - negative voltage 6 vdrop_adc[14] r y n y 16384 mv voltage representation of adc conversion of vbus voltage. range: 0 mv to 1000 mv default: 0 mv (0000000000000000) 5 vdrop_adc[13] r y n y 8192 mv 4 vdrop_adc[12] r y n y 4096 mv 3 vdrop_adc[11] r y n y 2048 mv 2 vdrop_adc[10] r y n y 1024 mv 1 vdrop_adc[9] r y n y 512 mv 0 vdrop_adc[8] r y n y 256 mv reg1a 7 vdrop_adc[7] r y n y 128 mv 6 vdrop_adc[6] r y n y 64 mv 5 vdrop_adc[5] r y n y 32 mv 4 vdrop_adc[4] r y n y 16 mv 3 vdrop_adc[3] r y n y 8 mv 2 vdrop_adc[2] r y n y 4 mv 1 vdrop_adc[1] r y n y 2 mv 0 vdrop_adc[0] r y n y 1 mv
48 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.25 reg1b and reg1c (vbat_adc) figure 44. reg1b and reg1c (vbat_adc) reg1b reg1c 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 26. reg1b and reg1c (vbat_adc) register bit field type reset description reg_rst watchdog en reg1b 7 vbat_pol r y n y indicates polarity of vbus voltage. always positive. 0 - positive voltage 1 - negative voltage 6 vbat_adc[14] r y n y 16384 mv voltage representation of adc conversion of vbat voltage. range: 2.048 v to 6.140 v default: 0 v (0000000000000000) 5 vbat_adc[13] r y n y 8192 mv 4 vbat_adc[12] r y n y 4096 mv 3 vbat_adc[11] r y n y 2048 mv 2 vbat_adc[10] r y n y 1024 mv 1 vbat_adc[9] r y n y 512 mv 0 vbat_adc[8] r y n y 256 mv reg1c 7 vbat_adc[7] r y n y 128 mv 6 vbat_adc[6] r y n y 64 mv 5 vbat_adc[5] r y n y 32 mv 4 vbat_adc[4] r y n y 16 mv 3 vbat_adc[3] r y n y 8 mv 2 vbat_adc[2] r y n y 4 mv 1 vbat_adc[1] r y n y 2 mv 0 vbat_adc[0] r y n y 1 mv
49 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.26 reg1d and reg1e (ibat_adc) figure 45. reg1d and reg1e (ibat_adc) reg1d reg1e 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 27. reg1d and reg1e (ibat_adc) register bit field type reset description reg_rst watchdog en reg1d 7 ibat_pol r y n y indicates polarity of battery current. 0 - positive voltage (default) 1 - negative voltage 6 ibat_adc[14] r y n y 16384 mv voltage representation of adc conversion of vbus voltage. range: 0 a to 7.104 a default: 0 a(0000000000000000) 5 ibat_adc[13] r y n y 8192 mv 4 ibat_adc[12] r y n y 4096 mv 3 ibat_adc[11] r y n y 2048 mv 2 ibat_adc[10] r y n y 1024 mv 1 ibat_adc[9] r y n y 512 mv 0 ibat_adc[8] r y n y 256 mv reg1e 7 ibat_adc[7] r y n y 128 mv 6 ibat_adc[6] r y n y 64 mv 5 ibat_adc[5] r y n y 32 mv 4 ibat_adc[4] r y n y 16 mv 3 ibat_adc[3] r y n y 8 mv 2 ibat_adc[2] r y n y 4 mv 1 ibat_adc[1] r y n y 2 mv 0 ibat_adc[0] r y n y 1 mv
50 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.27 reg1f and reg20 (ts_bus_adc) figure 46. reg1f and reg20 (ts_bus_adc) reg1f reg20 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 28. reg1f and reg20 (ts__bus_adc) register bit field type reset description reg_rst watchdog en reg1f 7 ts_bus_pol r y n y indicates polarity of ts_bus voltage. always positive. 0 - positive voltage 1 - negative voltage 6 ts_bus_adc [14] r y n y 16384 mv voltage representation of adc conversion of ts_bus voltage. range: 0 v to 2.420 v default: 0 v (0000000000000000) 5 ts_bus_adc [13] r y n y 8192 mv 4 ts_bus_adc [12] r y n y 4096 mv 3 ts_bus_adc [11] r y n y 2048 mv 2 ts_bus_adc [10] r y n y 1024 mv 1 ts_bus_adc [9] r y n y 512 mv 0 ts_bus_adc [8] r y n y 256 mv reg20 7 ts_bus_adc [7] r y n y 128 mv 6 ts_bus_adc [6] r y n y 64 mv 5 ts_bus_adc [5] r y n y 32 mv 4 ts_bus_adc [4] r y n y 16 mv 3 ts_bus_adc [3] r y n y 8 mv 2 ts_bus_adc [2] r y n y 4 mv 1 ts_bus_adc [1] r y n y 2 mv 0 ts_bus_adc [0] r y n y 1 mv
51 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.28 reg21 and reg22 (ts_bat_adc) figure 47. reg21 and reg22 (ts_bat_adc) reg21 reg22 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 29. reg21 and reg22 (ts_bat_adc) register bit field type reset description reg_rst watchdog en reg21 7 ts_bat_pol r y n y indicates polarity of ts_bat voltage. always positive. 0 - positive voltage 1 - negative voltage 6 ts_bat_adc [14] r y n y 16384 mv voltage representation of adc conversion of ts_bat voltage. range: 0 v to 2.420 v default: 0 v (0000000000000000) 5 ts_bat_adc [13] r y n y 8192 mv 4 ts_bat_adc [12] r y n y 4096 mv 3 ts_bat_adc [11] r y n y 2048 mv 2 ts_bat_adc [10] r y n y 1024 mv 1 ts_bat_adc [9] r y n y 512 mv 0 ts_bat_adc [8] r y n y 256 mv reg22 7 ts_bat_adc [7] r y n y 128 mv 6 ts_bat_adc [6] r y n y 64 mv 5 ts_bat_adc [5] r y n y 32 mv 4 ts_bat_adc [4] r y n y 16 mv 3 ts_bat_adc [3] r y n y 8 mv 2 ts_bat_adc [2] r y n y 4 mv 1 ts_bat_adc [1] r y n y 2 mv 0 ts_bat_adc [0] r y n y 1 mv 8.5.29 reg 23 (tdie_adc) figure 48. reg23 (tdie_adc) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 30. reg23 (tdie_adc) bit field type reset description reg_rst watchdog en 7 die_temp_adc [7] r y n y 128 c temperature representation of adc conversion of die junction temperature. range: 25 c to 150 c default: 0 c (0000000000000000) 6 die_temp_adc [6] r y n y 64 c 5 die_temp_adc [5] r y n y 32 c 4 die_temp_adc [4] r y n y 16 c 3 die_temp_adc [3] r y n y 8 c 2 die_temp_adc [2] r y n y 4 c 1 die_temp_adc [1] r y n y 2 c 0 die_temp_adc [0] r y n y 1 c
52 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.30 reg 24 (event_2_en) figure 49. reg24 (event_2_en) 7 6 5 4 3 2 1 0 0 0 0 0 1 0 0 0 r/w r r r r/w r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 31. reg24 (event_2_en) (0x24 register) bit field type reset description reg_rst watchdog en 7 vdrop_amp_dis r/w y n y turn on/ off vdrop amp 0 ? turn on vdrop amp (default) 1 ? turn off vdrop amp 6 reserved r n/a n/a n/a reserved bit. always reads 0. 5 reserved r n/a n/a n/a reserved bit. always reads 0. 4 reserved r n/a n/a n/a reserved bit. always reads 0. 3 ibus_ocp_en r/w y n y enable/ disable ibus over current protection 0 ? disable ibus ocp 1 ? enabled ibus ocp (default) 2 vbat_ovp_en r/w y n y enable/ disable vbat over voltage protection 0 ? disable vbat ovp (default) 1 ? enabled vbat ovp 1 ibat_ocp_en r/w y n y enable/ disable ibat over current protection 0 ? disable ibat ocp (default) 1 ? enabled ibat ocp 0 vout_ovp_en r/w y n y enable/ disable vout over voltage protection 0 ? disable vout ovp protection (default) 1 ? enabled vout_ovp
53 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.31 reg 25 (event_3_mask) figure 50. reg25 (event_3_mask) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r/w r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 32. reg26 (event_3_mask) (0x026 register) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 6 reserved r n/a n/a n/a reserved bit. always reads 0. 5 reserved r n/a n/a n/a reserved bit. always reads 0. 4 reserved r n/a n/a n/a reserved bit. always reads 0. 3 reserved r n/a n/a n/a reserved bit. always reads 0. 2 vbat_ovp_mask r/w y n y vbat over voltage fault mask. 0 ? no mask. int will assert low when vbat_ovp bit is set (default) 1 ? vbat_ovp is masked. int will not assert low when vbat_ovp bit is set. 1 ibat_ocp_mask r/w y n y ibat over current fault mask. 0 ? no mask. int will assert low when ibat_ocp bit is set (default) 1 ? ibat_ocp is masked. int will not assert low when ibat_ocp bit is set. 0 vout_ovp_mask r/w y n y vout over voltage fault mask. 0 ? no mask. int will assert low when vout_ovp bit is set (default) 1 ? vout_ovp is masked. int will not assert low when vout_ovp bit is set.
54 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.32 reg 26 (event_3) figure 51. reg26 (event_3) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset table 33. reg26 (event_3) (0x26 register) bit field type reset description reg_rst watchdog en 7 scp_flt r y n y indicates if high current from vbus to vout has hit i scp threshold. battery switch is disabled 0 ? no fault (default) 1 ? short circuit fault 6 reserved r n/a n/a n/a reserved bit. always reads 0. 5 reserved r n/a n/a n/a reserved bit. always reads 0. 4 reserved r n/a n/a n/a reserved bit. always reads 0. 3 vusb_ovp_flt r y n y indicates if vusb_ovp threshold is reached. battery switch is disabled 0 ? no fault (default) 1 ? vusb_ovp fault 2 vbat_ovp_flt r y n y indicates if vbat_ovp threshold is reached. battery switch is disabled 0 ? no fault (default) 1 ? vbat_ovp fault 1 ibat_ocp_flt r y n y indicates if ibat_ocp threshold is reached. battery switch is disabled 0 ? no fault (default) 1 ? ibat_ocp fault 0 vout_ovp_flt r y n y indicates if vout_ovp threshold is reached. battery switch is disabled 0 ? no fault (default) 1 ? vout_ovp fault 8.5.33 reg27 and reg28 (vusb_adc) figure 52. reg27 and reg28 (vusb_adc) reg27 reg28 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 r r r r r r r r r r r r r r r r legend: r/w = read/write; r = read only; -n = value after reset
55 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated table 34. reg27 and reg28 (vusb_adc) regi ster bit field type reset description reg_ rst watch dog en reg 21 7 vusb_pol r y n y indicates polarity of ts_bat voltage. always positive. 0 - positive voltage 1 - negative voltage 6 vusb_adc [14] r y n y 16384 mv voltage representation of adc conversion of vusb voltage. range: 2.048 v to 6.140 v default: 0 v (0000000000000000) 5 vusb_adc [13] r y n y 8192 mv 4 vusb_adc [12] r y n y 4096 mv 3 vusb_adc [11] r y n y 2048 mv 2 vusb_adc [10] r y n y 1024 mv 1 vusb_adc [9] r y n y 512 mv 0 vusb_adc [8] r y n y 256 mv reg 22 7 vusb_adc [7] r y n y 128 mv 6 vusb_adc [6] r y n y 64 mv 5 vusb_adc [5] r y n y 32 mv 4 vusb_adc [4] r y n y 16 mv 3 vusb_adc [3] r y n y 8 mv 2 vusb_adc [2] r y n y 4 mv 1 vusb_adc [1] r y n y 2 mv 0 vusb_adc [0] r y n y 1 mv
56 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.34 reg 29 (control_2) figure 53. reg29 (control_2) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 r r r r r r r r/w legend: r/w = read/write; r = read only; -n = value after reset table 35. reg29 (rsense) (0x29 register) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 4 reserved r n/a n/a n/a reserved bit. always reads 0. 3 reserved r n/a n/a n/a reserved bit. always reads 0. 2 reserved r n/a n/a n/a reserved bit. always reads 0. 1 reserved r n/a n/a n/a reserved bit. always reads 0. 6 vusbovp_th[ 1] r y n y indicates the vusb ovp threshold. 00 ? 5.5 v (default) 01 ? 6.5 v 10 ? 10.5 v 11 ? 14.0 v 5 vusbovp_th[ 0] r y n y 4 ovpset_dis r/w y n n disables the ovpset pin setting. when disabled, vusbovp threshold is only determined by the settings in vusbovp_i2c[2:1]. 0 ? enable ovpset pin (default) 1 ? disable ovpset pin 3 vusbovp_i2c[ 1] r/w y n y indicates the vusb ovp threshold. 00 ? 5.5 v 01 ? 6.5 v 10 ? 10.5 v 11 ? 14.0 v (default) 2 vusbovp_i2c[ 0] r/w y n y 1 reserved r n/a n/a n/a reserved bit. always reads 0. 0 r_place r/w y n y select location of srp/srn sense resistor 0 ? low-side placement (default) 1 ? high-side placement
57 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 8.5.35 reg 40 (die_temp_flt) figure 54. reg 40 (die_temp_flt) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 1 1 r r r r r r r/w r/w legend: r/w = read/write; r = read only; -n = value after reset table 36. reg 40 (die_temp_flt) (0x40 register) bit field type reset description reg_rst watchdog en 7 reserved r n/a n/a n/a reserved bit. always reads 0. 6 reserved r n/a n/a n/a reserved bit. always reads 0. 5 reserved r n/a n/a n/a reserved bit. always reads 0. 4 reserved r n/a n/a n/a reserved bit. always reads 0. 3 reserved r n/a n/a n/a reserved bit. always reads 0. 2 reserved r n/a n/a n/a reserved bit. always reads 0. 1 die_temp_flt [1] r/w y n y 30 c tshut temperature threshold offset: 105 c range: 105 c to 150 c default: 150 c (0b11) 0 die_temp_flt [0] r/w y n y 15 c
58 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 9 application and implementation note information in the following applications sections is not part of the ti component specification, and ti does not warrant its accuracy or completeness. ti ? s customers are responsible for determining suitability of components for their purposes. customers should validate and test their design implementation to confirm system functionality. 9.1 application information a typical application consists of the device configured as an i 2 c controlled device and another switch mode charger for li-ion and li-polymer batteries used in a wide range of smart phones and other portable devices. a host controls which charger is enabled during the charging process. 9.2 typical application figure 55. BQ25872 typical application copyright ? 2016, texas instruments incorporated power supply connector vout sda scl chgstat int batp batn srp srn sw sys bat sda/ scl vbus switch-mode charger host system battery pack vbus ts_vusb ts_bat gnd 1 p f vref gnd en vsys 10 p f (1) 100 : 100 : vref ovpgate 30.1 k ? 5.23 k ? vusb 103 at 103 at 5.23 k ? 30.1 k ?
59 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated typical application (continued) 9.2.1 design requirements table 37. design requirement parameter value input voltage range 3 v to 6 v input current limit 0.1 a to 7.5 a output voltage range 3 v to 4.975 v 9.2.2 detailed design procedure the BQ25872 continuously monitors battery and adaptor connector temperature by measuring the voltage between ts_bat pin and ts_bus pins and ground, typically determined by a negative temperature coefficient thermistor and an external voltage divider. the device compares this voltage against its internal thresholds to determine if charging is allowed. to initiate a charging cycle, both battery and connector temperatures must be lower than the temperature threshold, else the device suspends charging and waits until both temperatures are blow the threshold. assuming a 103 at ntc thermistor is used on the battery pack, the values rt1 (connected between ts_x pin to vref) and rt2 (connected between ts_x and ground) can be determined by using the following equations. where ? rth cold and v ltf are the resistance of ntc under the cold temperature and the corresponding ts_x pin voltage when charge is allowed, rth hot and v tco are the resistance of ntc under the hot temperature and the corresponding ts_x pin voltage when charge is allowed. (1) rt2 = v ref rth cold rth hot @ 1 v ltf f 1 v tco a rth hot @ v ref v tco f 1 a f rth cold @ v ref v ltf f 1 a rt1 = v ref v ltf f 1 1 rt2 + 1 rth cold
60 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 9.2.3 application curves figure 56. power up with ibus_reg = 1 a figure 57. ibat regulation during load step down figure 58. vbat regulation during load step down figure 59. ibus ocp during load transient figure 60. ts bus otp figure 61. vbus ovp with ibus regulation
61 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated figure 62. power up of BQ25872
62 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 10 power supply recommendations in order to provide an output voltage on sys, the device requires a power supply between 3.9-v and 14-v input with at least 100-ma current rating connected to vbus or a single-cell li-ion battery with voltage > vbatuvlo connected to bat. the source current rating needs to be at least 7.5 a to meet the current capability of the device. 11 layout 11.1 layout guidelines BQ25872 supports up to 7-a charge current. it is very critical to maximize cu trace of vbus and vout. following pcb layout guideline is recommended: ? use cu trace of at least 110 mil (2.794 mm) wide for vbus and vout respectively. this allows current flow evenly through all 7 wcsp solder balls. ? cu trace of vbus and vout should run at least 150 mil (3.81 mm) straight (perpendicular to wcsp ball array) before making turns. ? use as large as possible cu pour for vbus and vout trace elsewhere. ? use as large as possible cu pour for pgnd. ? place decoupling capacitors of vbus and vout as close as possible to the device. 11.2 layout example figure 63. BQ25872 layout diagram (top layer) figure 64. BQ25872 layout diagram (mid layer 2)
63 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated layout example (continued) figure 65. BQ25872 layout diagram (mid layer 1) figure 66. BQ25872 layout diagram (bottom 1)
64 BQ25872 sluscq6 ? october 2016 www.ti.com product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 12 device and documentation support 12.1 receiving notification of documentation updates to receive notification of documentation updates, navigate to the device product folder on ti.com. in the upper right corner, click on alert me to register and receive a weekly digest of any product information that has changed. for change details, review the revision history included in any revised document. 12.2 community resources the following links connect to ti community resources. linked contents are provided "as is" by the respective contributors. they do not constitute ti specifications and do not necessarily reflect ti's views; see ti's terms of use . ti e2e ? online community ti's engineer-to-engineer (e2e) community. created to foster collaboration among engineers. at e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. design support ti's design support quickly find helpful e2e forums along with design support tools and contact information for technical support. 12.3 trademarks e2e is a trademark of texas instruments. i 2 c is a trademark of philips semiconductor. all other trademarks are the property of their respective owners. 12.4 electrostatic discharge caution this integrated circuit can be damaged by esd. texas instruments recommends that all integrated circuits be handled with appropriate precautions. failure to observe proper handling and installation procedures can cause damage. esd damage can range from subtle performance degradation to complete device failure. precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 12.5 glossary slyz022 ? ti glossary . this glossary lists and explains terms, acronyms, and definitions.
65 BQ25872 www.ti.com sluscq6 ? october 2016 product folder links: BQ25872 submit documentation feedback copyright ? 2016, texas instruments incorporated 13 mechanical, packaging, and orderable information the following pages include mechanical, packaging, and orderable information. this information is the most current data available for the designated devices. this data is subject to change without notice and revision of this document. for browser-based versions of this data sheet, refer to the left-hand navigation.
package option addendum www.ti.com 7-oct-2016 addendum-page 1 packaging information orderable device status (1) package type package drawing pins package qty eco plan (2) lead/ball finish (6) msl peak temp (3) op temp (c) device marking (4/5) samples BQ25872yffr preview dsbga yff 42 3000 green (rohs & no sb/br) snagcu level-1-260c-unlim -40 to 85 BQ25872 BQ25872yfft preview dsbga yff 42 250 green (rohs & no sb/br) snagcu level-1-260c-unlim -40 to 85 BQ25872 (1) the marketing status values are defined as follows: active: product device recommended for new designs. lifebuy: ti has announced that the device will be discontinued, and a lifetime-buy period is in effect. nrnd: not recommended for new designs. device is in production to support existing customers, but ti does not recommend using this part in a new design. preview: device has been announced but is not in production. samples may or may not be available. obsolete: ti has discontinued the production of the device. (2) eco plan - the planned eco-friendly classification: pb-free (rohs), pb-free (rohs exempt), or green (rohs & no sb/br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. tbd: the pb-free/green conversion plan has not been defined. pb-free (rohs): ti's terms "lead-free" or "pb-free" mean semiconductor products that are compatible with the current rohs requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. where designed to be soldered at high temperatures, ti pb-free products are suitable for use in specified lead-free processes. pb-free (rohs exempt): this component has a rohs exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. the component is otherwise considered pb-free (rohs compatible) as defined above. green (rohs & no sb/br): ti defines "green" to mean pb-free (rohs compatible), and free of bromine (br) and antimony (sb) based flame retardants (br or sb do not exceed 0.1% by weight in homogeneous material) (3) msl, peak temp. - the moisture sensitivity level rating according to the jedec industry standard classifications, and peak solder temperature. (4) there may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) multiple device markings will be inside parentheses. only one device marking contained in parentheses and separated by a "~" will appear on a device. if a line is indented then it is a continuation of the previous line and the two combined represent the entire device marking for that device. (6) lead/ball finish - orderable devices may have multiple material finish options. finish options are separated by a vertical ruled line. lead/ball finish values may wrap to two lines if the finish value exceeds the maximum column width. important information and disclaimer: the information provided on this page represents ti's knowledge and belief as of the date that it is provided. ti bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. efforts are underway to better integrate information from third parties. ti has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ti and ti suppliers consider certain information to be proprietary, and thus cas numbers and other limited information may not be available for release.
package option addendum www.ti.com 7-oct-2016 addendum-page 2 in no event shall ti's liability arising out of such information exceed the total purchase price of the ti part(s) at issue in this document sold by ti to customer on an annual basis.
important notice texas instruments incorporated and its subsidiaries (ti) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per jesd46, latest issue, and to discontinue any product or service per jesd48, latest issue. buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. all semiconductor products (also referred to herein as ? components ? ) are sold subject to ti ? s terms and conditions of sale supplied at the time of order acknowledgment. ti warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in ti ? s terms and conditions of sale of semiconductor products. testing and other quality control techniques are used to the extent ti deems necessary to support this warranty. except where mandated by applicable law, testing of all parameters of each component is not necessarily performed. ti assumes no liability for applications assistance or the design of buyers ? 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