View MAX20082_8026377.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

general description the MAX20082 is a dual, full-bridge controller specifically designed for fault-tolerant automotive applications with high-power inductive loads such as brushed dc motors. the device has two fully independent motor-control channels designed for use with external n-channel power mosfets. each channel operates from a 4.75v to 5.25v input supply voltage range, and is capable of working with motor supply voltages up to 35v. a charge-pump regulator provides 9.8v gate drive with a 5v input supply voltage. a bootstrap capacitor is used to provide the voltage above the input battery voltage necessary to drive the high-side n-channel mosfets in the h-bridge. an internal top-off charge pump for the high- side drive allows dc (100% duty cycle) operation. the device also includes programmable dead time, gate- drive slew rate, and mosfet short-circuit threshold. the h-bridge can be driven in forward mode (clockwise), reverse mode (counterclockwise), braking mode, and coast mode. in braking mode, both the low-side mosfets are turned on (synchronous slow decay). in coast mode, all the mosfets in the h-bridge are off (asynchronous fast decay). the power mosfets are protected from shoot-through by a resistor-adjustable dead-time circuit. each channel also integrates a low-side current-sense amplifier. used for sensing motor (h-bridge) current, the current-sense amplifier includes an overcurrent-protec - tion circuit to limit the current in the event of motor faults. integrated diagnostics provide indication of undervolt - age, overtemperature, h-bridge, and pin faults and can be configured to protect the power mosfets under most short-circuit conditions. in addition, the device sup - ports implementation in asil systems by having two completely redundant h-bridge drivers in one package. the two channels are completely independent and fully redundant, with no shared pins or functions. the MAX20082 is specified for operation over the full -40c to +125c ambient temperature range. the maximum junction temperature is 150c, with thermal shutdown at 170c (typ). the device is available in a 56-pin, 14mm x 6.1mm, tssop package. benefts and features comprehensive ic diagnostics detect both ic and h-bridge faults, enhancing system safety both channels are fully independent without any shared pins or circuitry, providing complete redundancy resistor-programmable functionality simplifies software development all nfet operation, including 100% duty cycle, saves system cost applications automotive motor drivers industrial motor drivers ordering information appears at end of data sheet. 19-7047; rev 0; 8/14 control logic charge-pump doubler cp1c n1 cr1 sup1 in1 csp1 csn 1 cso1 fl t1 ls1 pa 1 coast1 bsta1 bstb1 dha 1 lxa1 lxb1 dla1 dlb1 pgnd1 agnd1 en1 pgnd1 dt1 diag1 slew1 v dsth1 dsth1 dhb 1 sup1 lxa1 lxb1 ls1 uv uv ic and asil diagnostics temp sensor 3.8v pb1 sup1 to p-off charge pump a to p-off charge pump b 1 of 2 channels MAX20082 cl uv/ov bootstrap monit or v ds comps bootstrap monit or block diagram evaluation kit available MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics
sup_, to agnd_ ................................................... -0.3v to +40v lxa_, lxb_, to agnd_ ........................................... -4v to +40v bsta_ to lxa_ ..................................................... -0.3v to +12v bstb_ to lxb_ ..................................................... -0.3v to +12v dha_ to lxa_ ......................................... -0.3v to v bst_ + 0.3v dhb_ to lxb_ ......................................... -0.3v to v bst_ + 0.3v cr_ to agnd_ ...................................................... -0.3v to +12v cn_ to agnd_ ......................................... -0.3v to (v in_ + 0.3v) cp_ to cn_ ............................................................ -0.3v to + 6v dla_, dlb_ to agnd_ ....................... -0.3v to + (v cr_ + 0.3v) in_ to agnd_ .......................................................... -0.3v to +6v coast_ , pa_, pb_, en_, diag_ , v dsth_ , slew_, dt_, cso_ to agnd_ ........ -0.3v to + (v in_ + 0.3v) flt_ , ls_, csp_, csn_ to agnd_ ...................... -0.3v to + 6v pgnd_ to agnd_ .................................................. -0.3v to 0.3v continuous power dissipation (t a = +70c) tssop on multilayer board (derate 10.8mw/c above +70c) ... 860mw operating ambient temperature range ........... -40c to +125c storage temperature range ............................ -55c to +150c maximum junction temperature ..................................... +150c lead temperature (soldering, 10s) ................................. +300c soldering temperature (reflow) ....................................... +260c tssop junction-to-ambient thermal resistance ( ja ) .......... 93c/w junction-to-case thermal resistance ( jc ) ............... 21c/w (electrical characteristics valid at t a = t j = -40c to 125c, v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, dh_ and dl_ open, unless otherwise noted.) (note 2) parameter symbol conditions min typ max units input supply voltage range v in 4.75 5.25 v input supply undervoltage lockout v inpuv rising 4 4.2 4.5 v v inuv hys hysteresis 200 mv start-up timer t start_up from en_ going high to v cr_ > cr uv_on , diag_ = low 13.5 20 ms from en_ going high to v cr_ > cr uv_on , diag_ = high 1.7 2 single-channel supply current i in_q flt_ and cso_ pin unconnected 1.7 3 ma v en_ = v pa_ = v pb_ = v diag_ = v coast_ = 0v 10 a cr_ output cr_ output voltage v cr_ i cr_ = 3ma. c cp_ = 330nf, cr_ = 3.3f 9.4 9.7 v i cr_ = 3ma, v in_ = 4.75v 8.9 9.2 cr_ undervoltage lockout cr uv_on rising 6.65 7 7.35 v cr uv_off hysteresis 500 mv cr_ charge timeout cr to v cr_ from 0v to cr uv_on 1.4 1.6 1.8 ms maxim integrated 2 note 1: package thermal resistances were obtained using the method described in jedec specification jesd51-7, using a four-layer board. for detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial . absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to ab solute maximum rating conditions for extended periods may affect device reliability. package thermal characteristics (note 1) electrical characteristics MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(electrical characteristics valid at t a = t j = -40c to 125c, v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, dh_ and dl_ open, unless otherwise noted.) (note 2) parameter symbol conditions min typ max units bootstrap circuit bootstrap voltage drop v bst_ v lx_ = 0v, i source = 10ma v cr_ - 0.2 v bootstrap input current i bst_ v bst_ = 24v, v lx_ = 14v 0.3 0.6 ma bst_ charge timeout bst to v bst_ from 0v to v boostuv, coast rising 0.7 0.8 0.9 ms bootstrap undervoltage threshold v boostuv rising (v bsta_ to v lxa_ or v bst_b to v lxb_ ) 6.7 7.2 7.6 v v boostuvh ys hysteresis (v bsta_ to v lxa_ or v bst_b to v lxb_ ) 1 v top-off charge-pump enable delay t to_en_dly pa_, pb_ rising 0.5 0.6 0.7 ms gate drive output-voltage high dh_ to lx_ v dh_high v bst_ = 9.5v, i source = 10ma, r slew_ = 10k? 9.1 9.3 v v bst_ = unconnected , v cr_ = 9.8v, i source = 25a 6.6 7.7 output-voltage low dh_ to lx_ v dh_low i sink = 10ma 0.2 0.5 v output-voltage high dl_ to pgnd_ v dl_high i source = 10ma, r slew_ = 10k?, v cr_ = 9.5v 9.1 9.3 v output-voltage low dl_ to pgnd_ v dl_low i sink = 10ma 0.2 0.5 v turn-off propagation delay t off see figure 4 for timing characteristics 60 100 150 ns turn-on propagation delay t on see figure 4 for timing characteristics 60 100 150 ns propagation delay matching 10 ns dead time t dead r dt_ = 10k? (see figure 4 for timing characteristics) 370 ns r dt_ = 40k? (see figure 4 for timing characteristics) 1100 r dt_ = 100k? (see figure 4 for timing characteristics) 2500 r dt_ = 200k? (see figure 4 for timing characteristics) 5000 slew current i slew r slew_ = 10k? 40 ma r slew_ = 50k?, v dl_ = v dh_ = 5v, v lx_ = 0v 8 ma r slew_ = 200k? 2 ma maxim integrated 3 electrical characteristics (continued) MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(electrical characteristics valid at t a = t j = -40c to 125c, v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, dh_ and dl_ open, unless otherwise noted.) (note 2) parameter symbol conditions min typ max units current-sense amplifier input common-mode voltage range cmvr 0 3 v input offset voltage v off -1.5 +1.5 mv input bias current i bias 200 -600 na input offset current i off 20 na differential dc voltage gain r cso_ = 2k? 90 105 db input capacitance c cs_in 5 pf output voltage range v cso_ i cso_ = 3ma 0.5 4.5 v output sink current i csosink v cso_ = 0v 10 50 ma output source current i cso source v cso_ = 5v 14 54 ma output slew rate sr gain > 10, c load = 100pf 10 v/s dc common-mode rejection cmr 81 100 db gain-bandwidth product gbw c load = 100pf 30 mhz phase margin sr c load = 100pf, gain = 10 66 overcurrent protection overcurrent threshold v oc v cso_ rising 3.5 3.75 4 v overcurrent threshold hysteresis v oc_hys 0.2 v v ds protection v dsth_ input voltage range v ds_rng 0.2 2 v v dsth_ accuracy v ds_acc v dsth_ = 0.5v -50 -60 mv v dsth_ input current v dsth_ 0.1 1 a v dsth_ disable voltage v ds_dis 2.6 v v dsth_ fault blanking time t vds_blank from dead time elapsed 12 15 18 s v dsth_ comp propagation delay t vds_del from fault time elapsed, 100mv overdrive 1 s lx_ input current i lx v en_ = 0v, v lx_ = 0 to 16v, no switching 250 a sup_ input current i sup_ 50 100 a ls_ input current i ls_ 30 a maxim integrated 4 electrical characteristics (continued) MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(electrical characteristics valid at t a = t j = -40c to 125c, v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, dh_ and dl_ open, unless otherwise noted.) (note 2) note 2: limits are 100% tested at t a = +25c. limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. note 3: minimum time en_ has to be low in order to enter reset state. note 4: minimum time en_ has to stay low after a power-up in order to enter shutdown mode. parameter symbol conditions min typ max units sup_ input protection overvoltage blanking time t blank_ov 350 400 450 ms sup_ undervoltage lockout sup uv rising 4.2 4.6 5 v sup uv_hys hysteresis 300 mv sup_ overvoltage lockout sup ov rising, more than t blank_ov 35 36.5 38 v sup ov_hys hysteresis 1.2 v thermal protection overtemperature fault threshold t jft_r rising 170 c t jft_f falling 145 fault flag fault output, low state v flt_low i sink = 1ma 0.3 v fault output leakage, high state i flt_high v flt_ = 5v -1 +1 a fault class 1 % flt_1 12.5 % diag_ low during pin-to-pin check routine 62.5 fault class 2 % flt_2 25 % fault class 3 % flt_3 50 % fault class 4 % flt_4 75 % fault class 5 % flt_5 87.5 % fault frequency f flt_ 550 625 700 khz en_, coast_ , pa_, pb_, and diag_ logic inputs input high voltage in vih 2 v input low voltage in vil 0.7 v input leakage current in lkg input voltage from 0 to 5.5v -1 +1 a en_ deglitch time t res note 3 7 10 13 s en_ pulldown resistor en _res 50 k? en_ low time to enter shutdown mode t shdw note 4 0.8 1 1.2 ms maxim integrated 5 electrical characteristics (continued) MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, unless otherwise noted.) 5v/div 5v/div toc02 2ms/div v flt1 power - up with pin to pin check (diag1 = low) v en1 v lxb1 v lxa1 5v/div 5v/div 0v 0v 0v, 0v 5v/div 5v/div toc03 4ms/div v flt1 power - up with pin -to- pin check interrupted v en1 v lxb1 v lxa1 5v/div 5v/div 0v 0v 0v, 0v v coast1 v diag1 0v 0v 5v/div 5v/div 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 4.7 4.9 5.1 5.3 5.5 v cr (v) v in (v) cr voltage vs. in voltage i cr = 0ma toc04 i cr = 1ma i cr = 3ma i cr = 5ma 9.70 9.72 9.74 9.76 9.78 9.80 9.82 9.84 9.86 -40 -25 -10 5 20 35 50 65 80 95 110 125 v cr (v) temperature ( c) cr voltage vs. temperature toc05 v in = 5v i cr = 5ma 5v/div 5v/div toc01 4ms/div v flt1 power - up without pin to pin check (diag1 = high) v en1 v lxb1 v lxa1 5v/div 5v/div 0v 0v 0v, 0v 0v 5v/div v coast1 0.0 0.5 1.0 1.5 2.0 2.5 -40 -25 -10 5 20 35 50 65 80 95 110 125 i in (ma) temperature ( c) single - channel supply current vs. temperature toc06 v in = 5v maxim integrated 6 typical operating characteristics MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, unless otherwise noted.) 0 1 2 3 4 5 6 7 8 9 10 -40 -25 -10 5 20 35 50 65 80 95 110 125 i in (a) temperature (oc) single - channel shutdown current vs. temperature v in = 5v toc07 0 1 2 3 4 5 6 7 20 70 120 170 220 dead time (s) r dt (k ? ) dead time vs. r dt toc08 1.08 1.09 1.10 1.11 1.12 1.13 -40 -25 -10 5 20 35 50 65 80 95 110 125 dead time (s) temperature (oc) dead time vs. temperature r dt = 40k toc09 high to low low to high 0 5 10 15 20 25 30 35 40 45 50 10 30 50 70 90 110 130 150 170 190 slew current (ma) r slew (k ? ) slew current vs. r slew toc10 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 slew current (ma) temperature (oc) driver slew current (sinking or sourcing) vs. temperature r slew = 51k toc11 0 20 40 60 80 100 120 0.001 0.1 10 1000 100000 cmrr (db) frequency (khz) csa common - mode rejection ratio vs. frequency toc12 -20 0 20 40 60 80 100 120 0.001 0.1 10 1000 100000 a vol (db) frequency (khz) csa open - loop gain vs. frequency toc13 3.60 3.65 3.70 3.75 3.80 3.85 3.90 3.95 4.00 -40 -25 -10 5 20 35 50 65 80 95 110 125 v cso (v) temperature (oc) overcurrent threshold vs. temperature toc14 35.0 35.1 35.2 35.3 35.4 35.5 35.6 35.7 35.8 35.9 36.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 v sup (v) temperature ( c) sup_ overvoltage threshold vs. temperature toc15 maxim integrated g 7 7slfdo2shudwlqj&kdudfwhulvwlfvfrqwlqxhg MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
(v in_ = 5v, v sup_ = 14v, v en_ = v diag_ = 3.3v, unless otherwise noted.) 5v/div 5v/div toc17 2s/div driver transient response to pa_ toggling (i motor = 3.5a source) 5v/div 0v 0v 0v 10v/div 0v v dha_ - v lxa_ v dla_ v pa_ v lxa_ 5v/div 5v/div toc18 2s/div driver transient response to pa_ toggling (i motor = 3.5a sink) 5v/div 0v 0v 0v 10v/div 0v v dha_ - v lxa_ v dla_ v pa_ v lxa_ 95.0 95.5 96.0 96.5 97.0 97.5 98.0 98.5 99.0 99.5 100.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 frequency (khz) temperature ( c) charge - pump frequency vs. temperature toc16 maxim integrated 8 typical operating characteristics (continued) MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
56 55 54 53 52 51 50 49 48 47 1 2 3 4 5 6 7 8 9 10 cp1 cn1 coast1 in1 lxa1 bsta1 sup1 cr1 top view MAX20082 pa1 pb1 diag1 en1 bstb1 ls1 dha1 cso1 flt1 dhb1 lxb1 46 45 44 43 42 41 40 39 38 37 v dsth1 dt1 slew1 agnd1 slew2 dt2 v dsth2 flt2 cso2 11 12 13 14 15 16 17 18 19 pgnd1 csn1 csp1 dlb1 dlb2 csp2 csn2 lxb2 dhb2 tssop 20 21 dha2 bstb2 24 36 33 en2 22 ls2 35 diag2 23 dla2 34 pb2 pa2 pgnd2 agnd2 + ep dla1 lxa2 25 32 bsta2 26 31 sup2 27 30 cr2 28 29 in2 coast2 cn2 cp2 maxim intatd pin confguration MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
pin name function 1 cr1 nominal 10v supply voltage for the gate drivers 2 sup1 high-side common drain connection and sense 3 bsta1 bootstrap capacitor connection for high-side drive a 4 lxa1 motor connection a 5 dha1 high-side gate drive a 6 dla1 low-side gate drive a 7 ls1 low-side common source connection 8 bstb1 bootstrap capacitor connection for high-side drive b 9 lxb1 motor connection b 10 dhb1 high-side gate drive b 11 dlb1 low-ide gate drive b 12 csp1 positive input current sense 13 csn1 negative input current sense 14 pgnd1 power ground 15 pgnd2 power ground 16 csn2 negative input current sense 17 csp2 positive input current sense 18 dlb2 low-side gate drive b 19 dhb2 high-side gate drive b 20 lxb2 motor connection b 21 bstb2 bootstrap capacitor connection for high-side drive b 22 ls2 low-side common source connection 23 dla2 low-side gate drive a 24 dha2 high-side gate drive a 25 lxa2 motor connection a 26 bsta2 bootstrap capacitor connection for high-side drive a 27 sup2 high-side common drain connection and sense 28 cr2 nominal 10v supply voltage for the gate drivers 29 cp2 charge-pump doubler capacitor connection p 30 cn2 charge-pump doubler capacitor connection n 31 coast2 active-low h-bridge disable input 32 in2 5v input supply 33 pa2 logic control input a 34 pb2 logic control input b 35 diag2 diagnostic input maxim integrated 10 pin description MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
pin name function 36 en2 enable input 37 cso2 input current-sense amplifer output 38 flt2 fault flag open-drain output 39 v dsth2 drain-to-source fault-threshold level input 40 dt2 dead-time resistor connection 41 slew2 slew-time resistor connection 42 agnd2 analog ground 43 agnd1 analog ground 44 slew1 slew-time resistor connection 45 dt1 dead-time resistor connection 46 v dsth1 drain-to-source fault-threshold level input 47 flt1 fault flag open-drain output 48 cso1 input current-sense amplifer output 49 en1 enable input 50 diag1 diagnostic input 51 pb1 logic control input b 52 pa1 logic control input a 53 in1 5v input supply 54 coast1 active-low h-bridge disable input 55 cn1 charge-pump capacitor connection n 56 cp1 charge-pump capacitor connection p maxim integrated 11 pin description (continued) MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
detailed description the MAX20082 is a dual, full-bridge controller specifically designed for use in fault-tolerant automotive applications, with high-power inductive loads such as brushed dc motors. the device has two fully independent motor- control channels designed for use with external n-channel power mosfets. each channel operates from a 4.75v to 5.25v input supply voltage range, and is capable of work - ing with motor supply voltages up to 35v. a charge-pump regulator provides 9.8v gate drive with a 5v input supply voltage. a bootstrap capacitor is used to provide the voltage above the input battery voltage necessary to drive the high-side n-channel mosfets in the h-bridge. an internal top-off charge pump for the high- side drive allows dc (100% duty cycle) operation. the device also includes programmable dead time, gate- drive slew rate, and mosfet short-circuit threshold. the h-bridge can be driven in forward mode (clockwise), reverse mode (counterclockwise), braking mode, and coast mode. in braking mode, both the low-side mosfets are turned on (synchronous slow decay). in coast mode, all the mosfets in the h-bridge are off (asynchronous fast decay). the power mosfets are protected from shoot-through by a resistor-adjustable dead time. each channel also integrates a low-side current-sense amplifier. used for sensing-motor (h-bridge) current, the current-sense amplifier includes an overcurrent- protection circuit to limit the current in the event of motor faults. integrated diagnostics provide indication of undervolt - age, overtemperature, h-bridge, and pin faults and can be configured to protect the power mosfets under most short-circuit conditions. in addition, the device supports implementation in asil systems by having two completely redundant h-bridge drivers in one package. the two channels are completely independent and fully redundant, with no shared pins or functions. the device is specified for operation over the full -40c to +125c ambient temperature range. the maximum junction temperature is +150c, with thermal shutdown at +170c (typ). the device is available in a 56-pin 14mm x 6.1mm tssop package. input supply individual 5v power-supply connections, isolated with fuses, should be provided to the device in order to guarantee fault isolation. decouple each supply with a 2.2f ceramic capacitor connected close to the in_ pins and ground pins. an rc filter, consisting of a 1? resistor in series with a 2.2f connected to agnd, is needed to prevent supply line transients from triggering undesired uvlo faults. the device operates within specified parameters with an input supply from 4.75 to 5.25 v. input supply undervoltage the device includes undervoltage-lockout circuitry (uvlo) on the in_ pins. input supply voltages of less than 4.25v inhibit operation of the device by turning off the driver outputs (motor in coast) and cr_ charge pump. charge pump a charge-pump doubler provides the voltage required to drive the switching mosfets in the h-bridge. the charge-pump boost converter doubles the input supply voltage (in_) through a pump capacitor connected between the cp_ and cn_ pins. this capacitor should typically be a 330nf ceramic type. the switching frequency of the charge pump is set at 100khz. the regulated voltage is available on the cr_ pin. connect a 3.3f ceramic capacitor between cr_ and agnd_ to provide the transient charging current to the low-side drivers and the bootstrap capacitors. the charge pump features undervoltage-lockout circuitry that turns off t he driver outputs (motor in coast) and cr charge pump when the cr_ voltage is lower than 7v (typ). see figure 1 . maxim integrated 12 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
top-off charge pump a top-off charge pump maintains the gate voltage on the external fets during 100% duty-cycle operation. it is a low-current trickle pump and operates only when the corresponding high-side fet has been on for at least 0.6ms (typ). without the top-off charge pump, this current would be drawn from the bootstrap capacitor causing it to discharge. the charge pump provides sufficient current to ensure that the bootstrap voltage is maintained close to twice the in_ voltage. the dynamic charge required to turn on the external fets is provided by the bootstrap capacitor. the top-off charge pump only provides the charge required to compensate for any leakage current that occurs on the high-side once the fet is on. low-side gate drivers the gate drivers are controlled by the logic inputs (pa_ and pb_). the low-side drivers are powered by the charge-pump output voltage on cr_. dla_ controls the low-side fet whose drain is connected to lxa_ and dlb_ controls the low-side fet whose drain is con - nected to lxb_. dla_ goes low to turn off the low-side fet whose drain is connected to lxa_ and dlb_ goes low to turn off the low-side fet whose drain is connected to lxb_. the rise and fall times can be controlled by a resistor on the slew_ pin and are designed to be symmetrical. additional increase in the slew times can be achieved by adding external resistors in series with the connection to the external fet gate. the dead time is controlled by a resistor on the dt_ pin and is also symmetrical. low-side mosfet drain connection the lxa_ and lxb_ pins are directly connected to the motor. these pins should be connected to the negative side of the bootstrap capacitors and are the negative rail connection for the high-side drivers. the discharge current from the high-side gate capacitance flows through these connections so a low-impedance connection is needed to the mosfet bridge. figure 1. charge-pump doubler cp_ cn_ in_ cr_ agnd_ 330nf 5v dc 10v dc 5v 10v 0v 5v 100khz 100khz 3.3f MAX20082 charge-pump doubler 2.2f maxim integrated g 13 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
high-side gate drivers the high-side gate drive outputs (dha_ and dhb_) are used to drive the high-side fets in the h-bridge. connect the external fet gates as close as possible to the dha_ and dhb_ pins. both the rise/fall times can be controlled by the resistor on the slew_ pin. additional gate-drive resistors can be added to increase the slew times beyond what is pro - grammed on the slew_ pin. the dead time is controlled by the resistor on the dt_ pin and is symmetrical. bootstrap capacitor connections these are the high-side connections for the bootstrap capacitors and are the positive supply for the high-side gate drives. the bootstrap capacitors are charged to approximately the cr_ voltage when the associated out - put lxa_ or lxb_ terminal is low. when the lxa_ or lxb_ output swings high, the charge on the bootstrap capacitor causes the voltage at the corresponding bsta_ or bstb_ terminal to rise with the output to provide the boosted gate voltage needed to drive the high-side mosfets. undervoltage circuitry monitors the voltage on the boot - strap capacitors and turns on the h-bridge low-side fets (see the faults description) if this voltage is lower than 60% of the cr_ voltage. a typical bootstrap capacitor value of 330nf is advised. dead-time programming dead time is defined as the time between the high/low side starting to turn off and the complementary side start - ing to turn on. dead time is required to prevent shoot- through in the mosfet bridge when the high- or low-side fet is turned off and the complementary low- or high-side fet is turned on. set the dead time for all the phases in one channel by a single resistor on the dt_ pin. the voltage on the dt_ pin is regulated to 1v 3% when a resistor greater than 10k? is connected from this pin to agnd_. the dead time is programmed by the current through the dt_ resistor, within a range between 370ns to 5s. the current flowing into the resistor on the dt_ pin is given by: i dt_ = 1/r dt_ where r dt_ is the resistor on the dt_ pin. for r dt_ values between 10k? and 200k? at 25c, the nominal value of the dead time (t dead ) is given by: t dead (r dt_ ) = 25 x r dt_ (k) + 100ns slew-time programming the gate pullup or pulldown current for all the fets is programmed by a resistor on the slew_ pin. this results in controlled lx_ rise and fall times, which are symmetri - cal and equivalent for all the fets in the h-bridge. the voltage on the slew pin is regulated to 1v 3% when a resistor greater than 10k? is connected from this pin to agnd_. the slew current is programmed within the 40ma and 2ma range. the current flowing into the resistor on the slew_ pin is given by: i slew_ = 1/r slew_ where r slew_ is the resistor on the slew_ pin. for r slew_ values between 10k? and 200k? at 25c, the nominal value of the slew current (i slew_ ) is given by: i slew_ (r slew_ ) = 400/r slew_ (k) ma slew time can be determined with the following formula, where q gd is the gate drain charge of the external nmos: t slew_ = q gd (nf)/i slew_ (ma) enable when en_ is low, the device is in shutdown mode and the maximum current drawn by each half of the device is less than 10a. to enter shutdown, hold en_ low for at least 1.2ms. maxim integrated 14 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
phase control the coast_ , pa_, and pb_ logic inputs allow motor control through a single-bit pwm digital signal. depending on the logic configuration of the pa_ and pb_ inputs, the c can select the direction of the motor and the current- decay mode during the off time (see figure 2 , figure 3 , and table 1 ). pa_ (pb_) 0 1 and coast_ = 1: 1) q2 (q4) is turned off and dead-time delay starts. 2) when dead-time delay elapses, q1 (q3) is turned on. pa_ (pb_) 1 0 and coast_ =1: 1) q1 (q3) is turned off and dead-time delay starts. 2) when dead-time delay elapses, q2 (q4) is turned on. figure 2. h-bridge logic (normal/diagnostic mode) figure 3. a_dt_elapsed signal used in dead-time generation table 1. phase control pa_ (pb_) coast_ q1 (q3) q2 (q4) 1 1 on off 0 1 off on x 0 off off pa _ pb_ q3 q1 q4 m b a q2 q1 q2 q3 q4 1 dead-time delay generator a_dt_elapsed b_dt_elapsed pa_toggle event pb_toggle event coast b_dt_elapsed 7 7 1 0 q4 0 1 q3 pb_ diag_ coast a_dt_elapsed 7 7 1 0 q2 0 1 q1 pa_ diag_ dead - time delay pa _ t oggle event a _ dt _ elapsed maxim integrated 15 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
table 2. h-bridge application table 3. truth table for external mosfet control pa_ pb_ coast_ on time off time pwm 0 1 forward (q1 and q4 on) ls brake (q2 and q4 on) 1 pwm 1 forward (q1 and q4 on) hs brake (q1 and q3 on) pwm pwm 1 forward (q1 and q4 on) reverse (q2 and q3 on) 0 pwm 1 reverse (q2 and q3 on) ls brake (q2 and q4 on) pwm 1 1 reverse (q2 and q3 on) hs brake (q1 and q3 on) pwm pwm 1 reverse (q2 and q3 on) forward (q1 and q4 on) pa_ pb_ coast_ diag_ q1 q2 q3 q4 h-bridge state 0 0 1 1 off on off on low sides on (ls brake) 0 1 1 1 off on on off reverse 1 0 1 1 on off off on forward 1 1 1 1 on off on off high sides on (hs brake) x x 0 x off off off off coast 0 0 1 0 on off off off fets diagnostic (q1 on) 0 1 1 0 off off off on fets diagnostic (q4 on) 1 1 1 0 off on off off fets diagnostic (q2 on) 1 0 1 0 off off on off fets diagnostic (q3 on) maxim integrated 16 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
figure 4. on time/forward; off time/brake (sync slow decay) q 3 q 1 q 4 q 2 m q 3 q 1 q 4 q 2 m q 3 q 1 q 4 q 2 m pa _ = pwm pb _ = 0 dha _ dla _ dhb _ dlb _ t dead t dead t prop t prop lxa _ t slew coast _ = 1 q 3 q 1 q 4 q 2 m q 3 q 1 q 4 q 2 m lx b _ t slew forward async slow decay sync slow decay async slow decay forward maxim integrated 17 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
current-sense amplifer and overcurrent detection the h-bridge current is sensed by the low-side current- sense amplifier. the open-loop gain of the current-sense amplifier is 110db and the closed-loop gain of this ampli - fier is set with external resistors (csa_g) according to: csa_g = r2/r1+1 with r3//r4 = r2 with additional external resistors, it is possible to add a bias voltage to the cso_ output to enable negative current monitoring during fast decay: bias = v ref x [r3/(r3 + r4)] the values of r1Cr4 must be chosen in accordance with table 4 in order to pass the power-up diagnostic test. an overcurrent fault is triggered when the output of the current-sense amplifier (cso_) reaches 3.8v. the motor overcurrent value can be estimated with the following formula: i motor_oc = (3.8v - bias)/(r sense x csa_g) the application circuit for a slow-decay case (i motor always positive) is shown in figure 7 . csa_g = 38, bias = 0v, csa closed-loop bandwidth = 790khz the application circuit for a fast-decay case (i motor is positive and negative) is shown in figure 8 . csa_g = 19, bias = 1.9v, csa closed-loop bandwidth = 1.6mhz figure 5. current-sense amplifier (typical configuration) figure 6. current-sense amplifier output characteristics r 4 v ref r1 r3 5v r2 csp_ r1 r sense i motor csn_ oc fault 3.8v cso_ 3 . 8 v 0 v bias cso _ v i motor 0 a r sense x csa _ g maxim integrated 18 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
figure 7. current-sense amplifier configuration (positive current only) figure 8. current-sense amplifier configuration (bidirectional current flow) bias 5v csp_ r sense i motor csn_ oc fault 3.8v cso_ 3.8v 0v cso_ v 50a i motor 0a csp_ csn_ r1 cso_ i motor r sense 3.8v oc fault vref 5v r2 r1 r4 r3 3.8v 0v 1.9v cso_ v i motor 0a 50a -50a maxim integrated 19 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
power-up diagnostic mode after power-up, every time en_ goes high with diag_ low, the diagnostic power-up routine starts. the device performs the following checks for each pin: ? is the pin shorted to ground? ? is the pin open? ? is the pin shorted to an adjacent pin? the diagnostic strategy is based on a sequential routine that starts from the v dsth_ pin and proceeds counter - clockwise to end at the coast_ pin. in the event of a diagnostic error during the sequential check, the diagnos - tic sequence is terminated and an asil fault is declared at the flt_ pin by forcing the duty of the output signal to 25%. pins lx_, dh_, dl_, bst_, sup_, and ls_ are not checked during this power-up diagnostic routine. their functionality can be verified during the fet diagnostic mode, as described in the fet diagnostic mode section. fet diagnostic mode during normal operation (after power-up is completed, en_ pin high), fet diagnostic mode can be entered by forcing diag_ = 0. the lxa_ and lxb_ pins are then connected through an internal 1k? (typ) pulldown/ pullup to pgnd_/sup_, based on the selected fet under diagnosis. v ds fault and overcurrent event can be used to check the motor and h-bridge status in fet diagnostic mode. table 4. power-up diagnostic pin setting table 5. fet control pin condition to pass power-up test cr_ 3.3f 10% ceramic capacitor connected to ground. csp_ place an equivalent resistance with a value between 500? and 2k?. csn_ place an equivalent resistance with a value between 500? and 2k?. cso_ place a feedback resistance with a value between 5k? and 100k?. pgnd_ connect to the ground plane of the system board. slew_ place a resistance with a value between 10k? and 200k?. dt_ place a resistance with a value between 10k? and 200k?. v dsth_ place an equivalent resistance with a value between 500? and 10k?. flt_ connect a resistance with a value between 1k? and 3.3k? to in_. en_ connect to in_ through external driving circuitry. diag_ connect to agnd_/pgnd_ or in_ through external driving circuitry. pa_ connect to agnd_/pgnd_ through external driving circuitry. pb_ connect to in_ through external driving circuitry. coast_ connect to agnd_/pgnd_ through external driving circuitry. coast_ pa_ pb_ fet on lxa_ status lxb_ status 1 0 0 q1 pulldown to ground hi-z 1 1 1 q2 pullup to sup_ hi-z 1 1 0 q3 hi-z pulldown to ground 1 0 1 q4 hi-z pullup to sup_ maxim integrated 20 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
power-up scenarios see figure 9 , figure 10 , and figure 11 for power-up scenarios. table 6. interpreting fault information in diagnostic mode figure 9. power-up sequencing with pin-to-pin check enabled turned on nmos v ds fault v ds and overcurrent event q1 q1 open or motor terminal a shorted to ground q2 shorted q2 q2 open or motor terminal a shorted to sup_ q1 shorted q3 q3 open or motor terminal b shorted to ground q4 shorted q4 q4 open or motor terminal b shorted to sup_ q3 shorted en pa_ coast_ diag_ flt_ fsm state cr_ hb state 0 . 1 ms coast coast ls on selected fets on cr pu select fet to turn on normal normal bst refresh pin-to-pin check 12 . 5 % 1 . 6 ms typ 12 ms typ pb_ 2 ms max 1) diag_ has to be kept low for at least 20ms after en high in order to complete the pin-to-pin check properly. power-up with p2p check interrupted 62 . 5 % 0 . 82 ms typ maxim integrated 21 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
figure 10. power-up sequencing with pin-to-pin check disabled en pa_ coast_ diag_ flt_ fsm state cr_ hb state 0 . 1 ms coast ls on selected fets on cr pu select fet to turn on normal normal bst refresh 12 . 5 % 1 . 6 ms pb_ 2ms max power-up without p 2 p check 0 . 82 ms maxim integrated 22 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
figure 11. power-up sequencing with pin-to-pin check interrupted en pa _ coast _ diag _ flt _ fsm state cr _ hb state 0 . 1 ms coast ls on selected fets on cr pu select fet to turn on normal normal bst refresh pin - to - pin check 12 . 5 % 1 . 6 ms < 12 ms pb _ 2 ms max power - up with p 2 p check interrupted 62 . 5 % 0 . 82 ms maxim integrated 23 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
state diagram see figure 12 for the fsm state diagram. figure 12. fsm state diagram shutdown / low power mode cr hb flt off hiz hiz reset cr hb flt off hiz hiz en = 1 & in ok asil d cr hb flt off hiz 62 . 5 % cr power up timeout = 1 . 64 ms cr hb flt on hiz 1 2 . 5 % bst deglitch timeout = 0 . 82 ms cr hb flt on low 1 2 . 5 % cr ok normal / diagnostic cr hb flt on user 1 2 . 5 % bst ok in uv cr uv fault cr hb flt off hiz 50 % cr uv sup ov fault cr hb flt on hiz 50 % sup ov > 400 ms sup ok thermal shutdown cr hb flt on hiz 87 . 5 % tsd = 1 tsd = 0 oc fault cr hb flt on user 7 5 % oc = 1 oc = 0 vds fault cr hb flt on hiz 25 % vds = 1 en = 0 for t > 1 ms asil fault cr hb flt off hiz 25 % asil ko sup uv fault cr hb flt on hiz 50 % sup uv sup ok fault priority 1 ) in uv -- 100 % 2 ) asil C 25 % 3 ) cr uv C 50 % 4 ) vds fault C 25 % 5 ) bst uv C 50 % 6 ) tsd C 87 . 5 % 7 ) sup ov C 50 % 8 ) oc fault C 7 5 % 9 ) sup uv C 50 % in uv asild cr uv bst uv sup ov vds sup uv tsd oc in uv asild cr uv bst uv sup ov vds sup uv tsd oc ( in ok & diag b = 0 & en = 1 ) | ( tm & tm _ asil _ edge ) in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv vds tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc bst uv fault cr hb flt on low 50 % bst ok in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc b / s ov sup uv in uv asild cr uv bst uv b / s ov vds sup uv tsd oc in uv asild cr uv bst uv sup ov vds sup uv tsd oc in uv asild cr uv bst uv b / s ov vds sup uv tsd oc vdd ok & diag b = 1 & en = 1 en=0 en =0 en = 0 ( asil _ ok | diagb = 1 ) & ~ tm tm tm & asil _ ok coastb = 1 bst uv condition is checked condition is ignored maxim integrated 24 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
bst fault a bst fault is detected (except in coast mode, when it is masked) when the voltage on any of the bst_ capacitors falls below 7v (typ). when this happens, normal opera - tion of the h-bridge is impossible until the bst_ capacitor is recharged. to avoid faults due to undervoltage on the boost (bst_) capacitors, a bst fault deglitch timer is incorporated in the device. at each low-to-high transition of the coast_ pin, the deglitch timer is activated. during the deglitch time, the internal logic of the device takes control and the dla and dlb outputs are forced high in order to turn on the external low-side mosfets and refresh the charge on the boost capacitors. when this timer elapses, the bootstrap capacitors are fully charged and ready to operate the motor. when a bst fault occurs (in the absence of faults), it is normally suffcient to perform a boost-capacitor refresh by taking coast_ low and then high again and waiting at least 0.9ms until the bst fault deglitch timer elapses. v ds fault every time an fet of the h-bridge is turned on, a dedicated drain-source comparator checks if its drain- source voltage is lower or higher than the v ds voltage threshold set through the v dsth_ pin. if the fet drain- source voltage is higher than the voltage on the v dsth_ pin, a fault is detected. to avoid false error detection, the v ds comparators are inhibited after mosfet power-on for a blanking time (t blank ). connect v dsth_ to in_ to disable the v ds fault-detection circuitry. sup_ undervoltage and overvoltage protections the device includes undervoltage and overvoltage detection circuitry on the sup_ pins. if the voltage is less than 4.5v, a sup_ undervoltage fault is signaled through the flt_ pin and all the mosfet drivers are turned off. if the sup_ voltage exceeds 35v for more than 400ms, a sup_ overvoltage fault is detected and all the drivers are turned off (h-bridge). fault behavior the flt_ pin indicates detected faults by means of a 625khz signal, with varying duty cycle according to table 7 . table 7. fault classes and the flt_ output fault class fault description duty cycle of flt_ (%) 1 none 12.5 2 v ds fault, asil fault 25 3 sup_ overvoltage (sup_, cr_ and bst_ undervoltage) 50 1 none (pin-to-pin check routine ongoing) 62.5 4 overcurrent 75 5 thermal shutdown 87.5 6 in_ undervoltage 100 maxim integrated 25 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
applications information power dissipation to evaluate the devices power consumption, it is necessary to calculate the total supply current from the supply input pin (in_) for a single channel: i in_ = i in_q + 4 x q g x f pwm where i in_q is the quiescent current, q g is the total gate charge of the external nmos, and f pwm is the pwm switching frequency. the devices total power dissipation is then (for both channels): pd = 2 x [v in_ x i in_ ] layout guidelines for best performance, it is advisable to use the following guidelines when designing the pcb for the MAX20082: ? use separate analog ground (agnd) and power ground (pgnd) planes and connect them at a single point. implement connections between the same grounds on different layers with multiple vias. ? maintain the input and output power sections (connec - tions to sup_, lxa_, lxb_, and ls_) as compact as possible. ? use wide traces to connect the components related to the high-current paths. ? use multiples vias to connect high-current paths that must pass from one layer to another. ? make the mosfet gate-drive traces (dha_, dhb_, dla_, and dlb_) as short as possible and use large track widths. ? place the boost capacitors (between cp_ and cn_), charge-pump output capacitors (on cr_), and the input capacitors (on in_) close to the ic and connect them without using vias. ? the current-sense connections should be kelvin connected. contact your maxim integrated representative for further details on choosing and placing external components. table 8. fault summary * coast = motor in hi-z. fault fault description duty cycle (%) cr_ h-bridge fets state latched fault reset none 12.5 on user control no overcurrent v cso_ > 3.8v 75 on user control no v ds fault ( diag_ = x) fet on-drain source voltage > v dsth_ 25 on off (coast*) yes en_ low pulse in_ undervoltage v in_ < v inuv 100 off off (coast*) no cr_ undervoltage cr_ < v cruv 50 off off (coast*) yes en_ low pulse bsta_/bstb_ undervoltage bst_ - lx_ < v bstuv 50 on dla_, dlb_ high no sup_ undervoltage sup_ < v supuv 50 on off (coast*) no sup_ overvoltage sup_ > 36v for t > 400ms 50 on off (coast*) no thermal shutdown t j > t jtsd 87.5 on off (coast*) no maxim integrated 26 MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
control logic c r 1 sup 1 in 1 cs p 1 cs n 1 flt 1 ls 1 pa 1 coast 1 bst a 1 bstb 1 dh a 1 lx a 1 lx b 1 dl a 1 dl b 1 pgnd 1 agnd 1 en 1 pgnd 1 dt 1 diag 1 slew 1 v ds th 1 dh b 1 sup 1 uv uv ic and asil d iagnostics temp sensor 3 . 8 v pb 1 sup 1 top - off charge pump a top - off charge pump b max 20082 cl uv / ov bootstrap monitor bootstrap monitor 2 . 2 f 1 5 v in lxa 1 lxb 1 ls 1 cs o 1 charge - pump doubler c p 1 c n 1 optional rc filter v ds comps to adc 3 . 3 f 330 nf 20 motor q 1 q 2 q 3 q 4 20 battery pmos v adcref cs 01 10 m 220 nf maxim integrated 27 7slfdossolfdwlrq&lufxlw&kdqqho6krzq MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
/v denotes an automotive qualified part. +denotes a lead(pb)-free/rohs-compliant package. t = tape and reel. part temp range pin-package MAX20082aun/v+t -40c to +125c 56 tssop package type package code outline no. land pattern no. 56 tssop u56n+2c 21-0481 90-0338 maxim integrated 28 package information for the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. chip information process: bicmos ordering information MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics www.maximintegrated.com
revision number revision date description pages changed 0 8/14 initial release ? 2014 maxim integrated products, inc. 29 revision history maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and specifcations without notice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. MAX20082 dual, redundant, h-bridge motor driver with asil diagnostics for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com.

▲Up To Search▲

Price & Availability of MAX20082

	To Download MAX20082 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .