rt9701 1 ds9701-16 april 2011 www.richtek.com pin configurations 100m power distribution switches marking information for marking information, contact our sales representative directly or through a richtek distributor located in your area. ordering information (top view) typical application circuit general description the rt9701 is an integrated 100m power switch for self-powered and bus-powered universal series bus (usb) applications. a built-in charge pump is used to drive the n-cha nnel mosfet that is free of parasitic body diode to eliminate any reversed current flow across the switch when it is powered off. its low quiescent current (23ua ) and small package (sot-23-5) is particularly suitable in battery-powered portable equipment. several protection functions include soft start to limit inrush current during plug-in, current limiting at 1.5a to meet usb power requirement, and thermal shutdown to protect damage under over current conditions. applications z battery-powered equipment z motherboard usb power switch z usb device power switch z hot-plug power supplies z battery-charger circuits features z z z z z 100m typ. high-side nmosfet ( sot-23- 5) z z z z z guaranteed 1.1a continuous current z z z z z 1.5a current limit z z z z z small sot-23-5 package minimizes board space z z z z z soft start z z z z z thermal protection z z z z z low 23ua supply current z z z z z wide input voltage range : 2.2v to 6v z z z z z ul approved - #e219878 z z z z z rohs compliant and 100% lead (pb)-free note : richtek products are : ` rohs compliant and compatible with the current require- ments of ipc/jedec j-std-020. ` suitable for use in snpb or pb-free soldering processes. sot-23-5 (l-type) sot-23-5 rt9701xbl vin vin vout vout gnd v out v in c in 1uf * c out 470uf * 470uf, low esr electrolytic vout gnd vin vout en 4 23 5 vout gnd vin vout vin 4 23 5 rt9701 package type b : sot-23-5 bl : sot-23-5 (l-type) lead plating system p : pb free g : green (halogen free and pb free)
rt9701 2 ds9701-16 april 2011 www.richtek.com function block diagram test circuits test circuit 1 test circuit 2 test circuit 3 test circuit 2 is performed by charging an external tank of bulk capacitor to the input then applying this voltage to the input of the unit. all typical operating characteristics curves showed are referred to test circuit 1, unless specified to test circuit 2 or test circuit 3. control thermal detection current limit bias charge pump oscillator nmosfet rs en vin (vin) (vout) vout gnd functional pin description pin name pin function vin power input voltage vout output voltage gnd ground en chip enable (active h igh) rt9701xbl vin vin vout vout gnd v out v in c in 1uf i out r l c l + i l + rt9701xbl vin vin vout vout gnd v out v in c in 1uf r l c l + v in-sw + switch off rt9701xb vin en vout vout gnd v out v in c in 1uf i out r l c l + i l + chip enable
rt9701 3 ds9701-16 april 2011 www.richtek.com electrical characteristics absolute maximum ratings z supply voltage --------------------------------------------------------------------------------------------------------- 7v z chip enable ------------------------------------------------------------------------------------------------------------- ? 0.3v to 7v z power dissipation, p d @ t a = 25 c sot-23-5 ---------------------------------------------------------------------------------------------------------------- 0.25w z package thermal resistance sot-23-5 , ja ----------------------------------------------------------------------------------------------------------- 250c /w z lead temperature (soldering, 10 se c.) --------------------------------------------------------------------------- 260 c z operating junction temperature range -------------------------------------------------------------------------- ? 20 c to 100 c z storage temperature range ---------------------------------------------------------------------------------------- ? 65 c to 150 c z v out esd level hbm (human body mode) ------------------------------------------------------------------------------------------ 8kv mm (ma chine mode) -------------------------------------------------------------------------------------------------- 800v parameter symbol test conditions min typ max units input voltage range v in 2.2 -- 6 v output nmosfet r ds(on) rt9701xbl r ds(on ) i l = 1a -- 85 100 m rt9701xb i l = 1a -- 87 100 quiescent current v in = 3 v -- 19 40 a v in = 5 v -- 23 45 output turn-on rising time t r r l = 10 , 90% settling -- 400 -- s current limit threshold i limit r l = 2 1.1 1.5 2 a short-circuit fold back current i os v out = 0v, measured prior to thermal shutdown -- 1.0 -- a en input high threshold rt9701xb 2.0 -- -- v en input low threshold rt9701xb -- -- 0.8 v shutdown supply current rt9701xb i off en = ?0? -- 0.1 1 a output leakage c urrent rt9701xb i leakage en = ?0?, v out = 0v -- 0.5 10 a v in under voltage lockout u vlo 1.3 1.8 -- v v in under voltage h ysteresis -- 100 -- mv thermal limit t sd -- 130 -- c thermal limit hysteresis t sd -- 20 -- c (v in = 5v, c in = c out = 1 f, t a = 25c, unless otherwise specified)
rt9701 4 ds9701-16 april 2011 www.richtek.com typical operating characteristics quiescent current vs. temperature 0 5 10 15 20 25 30 35 40 -40 -20 0 20 40 60 80 100 120 temperature quiescent current ( ua) ( c) v in = 5v quiescent current vs . input voltage 0 5 10 15 20 25 30 35 40 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 input voltage (v) quiescent current (ua) t a = 25 c on-resistance vs. temperature 0 50 100 150 200 -40-20 0 20 40 60 80100120 temperature ( ) on-resistance (m ? ) v in = 5v rt9701xb rt9701xbl ( c) current limit vs. temperature 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 -40-20 0 20406080100120 temperature current limit (a) ( c) v in = 5v current limit vs. input voltage 0.00 0.23 0.45 0.68 0.90 1.13 1.35 1.58 1.80 2.02.53.03.54.04.55.05.56.0 input voltage (v) current limit (a) t a = 25 c on-resistance vs. input voltage 80 85 90 95 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 input voltage(v) on-resistance (m ? ) t a = 25 c rt9701xb rt9701xbl
rt9701 5 ds9701-16 april 2011 www.richtek.com en threshold vs. input voltage 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 input voltage (v) en threshold (v) rising falling *test circuit 3 t a = 25 c en pin threshold voltage vs. input en pin threshold voltage (v) short circuit current vs. input voltage 200 450 700 950 1200 1450 1700 1950 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 input voltage (v) short circuit current (ma) t a = 25 c short circuit current vs. temperature 500 600 700 800 900 1000 1100 1200 1300 1400 -40-20 0 20406080100120 temperature ( c) short circuit current (ma) 1 ( c) v in = 5v en threshold vs. temperature 0.0 0.4 0.8 1.2 1.6 2.0 2.4 -40 -20 0 20 40 60 80 100 120 temperature en threshold (v) ( c) v in = 5v rising falling *test circuit 3 en pin threshold voltage (v) en pin threshold voltage vs. turn off falling time v s. temperature 0 20 40 60 80 100 120 140 -40 -20 0 20 40 60 80 100 120 temperature turn-off falling time (us) r l = 30 c l = 1uf ceramic *test circuit 3 ( c) v in = 5v turn on rising time vs. temperature 0 90 180 270 360 450 540 630 720 -40-20 0 20406080100120 temperature turn-on rising time (us) ( c) v in = 5v r l =30 c l = 1uf ceramic *test circuit 3
rt9701 6 ds9701-16 april 2011 www.richtek.com shutdown supply current vs. temperature 0.0 0.2 0.3 0.5 0.6 0.8 0.9 -40 -20 0 20 40 60 80 100 120 temperature shutdown supply current (ua) ( c) *test circuit 3 v in = 5v turn-off leakage current vs. temperature 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 -40-20 0 20406080100120 temperature turn-off leakage current (ua) a ( c) *test circuit 3 v in = 5v uvlo threshold vs. temperature 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 -40 -20 0 20 40 60 80 100 120 temperature uvlo threshold (v) ( c) v in = 5v inrush current response time (100us/div) c l = 100uf c l = 33uf i l = 1a/div, r l = 1 , v in = 5v c l = 1uf time (100us/div) turn - on response *test circuit 3 r l = 30 , c l = 1uf ch1 ch2 ch1: v en : 5v/div ch2: v out : 1v/div ch2 turn - off response time (50us/div) *test circuit 3 r l = 30 , c l = 1uf ch1 ch3 ch1: v en : 5v/div ch2: i out : 100ma/div ch3: v out : 2v/div
rt9701 7 ds9701-16 april 2011 www.richtek.com ramped load response time (1ms/div) v in = 5v, c l = 1uf v out = 5v v out = 4.6v 4.9v 1.1v current limit threshold ch2 ch2: i out : 500ma/div ch1 c in = 1uf ch1: v in : 2v/div ch1 ch2 ch2: i out : 1a/div soft - start short circuit response time (5us/div) inrush short circuit response time (25us/div) c in = 1uf, c l = 1000uf ch1 ch2 ch2: i l : 10a/div ch1: v in : 2v/div v drop =1.2v, depend on c in esr i peak : depend on esr & esl current limit response time (5us/div) loading trigger v in = 5v, c l = 0.1uf r l = 1 ch2: i out : 1a/div ch2 ch1 uvlo at falling time (100ms/div) *test circuit 2 ch1: v in : 1v/div ch2: v out : 1v/ div r l = 30 , c l = 1uf ch1 ch2 ch1 uvlo at rising time (500us/div) ch1: v in : 1v/div ch2: v out : 1v/div r l = 30 , c l = 1uf ch2
rt9701 8 ds9701-16 april 2011 www.richtek.com application information the rt9701 is a high-side single n-chann el mosfet switch with active-high enable input. input and output vin (input) is the power supply connection to the circuitry and the drain of the output mosfet. vout (output) is the source of the output mosfet. in a typical circuit, current flows through the switch from vin to vout toward the load. both vout pins must be short on the board and connected to the load and so do both vin pins but connected to the power source. thermal shutdown thermal shutdown shuts off the output mosfet if the die temperature exceeds 130 c and 20 c of hysteresis forces the switch turning off until the die temperature drops to 110 c. soft start in order to eliminate the upstream voltage droop caused by the large inrush current during hot-plug events, the ? soft-start ? feature effectively isolates power supplies from such highly capacitive loads. under-voltage lockout uvlo prevents the mosfet switch from turning on until input voltage exceeds 1.8v (typical). if input voltage drops below 1.8v (typical), uvlo shuts off the mosfet switch. filtering to limit the input voltage drop during hot-plug events, connect a 1uf ceramic capacitor from vin to gnd. however, higher capacitor values will further reduce the voltage drop at the input. connect a sufficient capacitor from vout to gnd. this capacitor helps to prevent inductive parasitics from pulling vout negative during turn-off or emi damage to other components during the hot-detachment. it is also necessary for meeting the usb specification during hot plug-in operation. if rt9701 is implanted in device end application, minimum 1uf capacitor from vout to gnd is recommended and higher capacitor values are also preferred. figure 1. high side power switch figure 2. high side power switch with chip enable control current limiting and short protection the current limit circuit is designed to protect the system supply, the mosfet switch and the load from damage caused by excessive currents. the current limit threshold is set internally to allow a minimum of 1.1a through the mosfet but limits the output current to approximately 1.5a typical. when the output is short to ground, it will limit to a constant current 1a until thermal shutdown or short condition removed. rt9701xbl vin vin vout vout gnd v out2 v in c in 1uf c out c in = 1uf, c out = 470uf (low esr) on m/b c in = 1uf, c out = 330uf (low esr) on notebook c in = 10uf, c out = 1uf on usb device v out1 c out rt9701xb vin en vout vout gnd v out2 v in c in c out v out1 c out chip enable thermal shut dowm response time (50ms/div) ch1 ch1: v en = 5v/div, ch3: i out @r l 1 : 1a/div ch2: i out @short : 1a/div, v in = 5v ch2 thermal shut down ch3
rt9701 9 ds9701-16 april 2011 www.richtek.com in choosing these capacitors, special attention must be paid to the effective series resistance, esr, of the capacitors to minimize the ir drop across the capacitor esr. a lower esr on this capacitor can get a lower ir drop during the operation. ferrite beads in series with all power and ground lines are recommended to eliminate or significantly reduce emi. in selecting a ferrite bead, the dc resistance of the wire used must be kept to a minimum to reduce the voltage drop. reverse current preventing the output mosfet and driver circuitry are also designed to allow the mosfet source to be externally forced to a higher voltage than the drain (vout > vin 0). to prevent reverse current from such condition, disable the switch (rt9701xb) or connect vin to a fixed voltage under 1.3v. layout and thermal dissipation z place the switch as close to the usb connector as possible. keep all traces as short as possible to reduce the effect of undesirable parasitic inductance. z place the ot capacitor and ferrite beads asclose to the usb connector as possible. z if ferrite beads are used, use wires with minimum resistance and large solder pads to minimize connection resistance. z if the package is with dual vout or vin pins, short both the same function pins as figure 1 or figure 2 to reduce the internal turn-on resistance. if the output power will be delivered to two individual ports, it is specially necessary to short both vout pin at the switch output side in order to protect the switch when each port are plug-in separately. z under normal operating conditions, the package can dissipate the channel heat away. wide power-bus planes connected to vin and vout and a ground plane in contact with the device will help dissipate additional heat.
rt9701 10 ds9701-16 april 2011 www.richtek.com richtek technology corporation headquarter 5f, no. 20, taiyuen street, chupei city hsinchu, taiwan, r.o.c. tel: (8863)5526789 fax: (8863)5526611 richtek technology corporation taipei office (marketing) 5f, no. 95, minchiuan road, hsintien city taipei county, taiwan, r.o.c. tel: (8862)86672399 fax: (8862)86672377 email: marketing@richtek.com information that is provided by richtek technology corporation is believed to be accurate and reliable. richtek reserves the ri ght to make any change in circuit design, specification or other related things if necessary without notice at any time. no third party intellectual property inf ringement of the applications should be guaranteed by users when integrating richtek products into any application. no legal responsibility for any said applications i s assumed by richtek. outline dimension a a1 e b b d c h l sot-23-5 surface mount package dimensions in millimeters dimensions in inches symbol min max min max a 0.889 1.295 0.035 0.051 a1 0.000 0.152 0.000 0.006 b 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 0.022 c 2.591 2.997 0.102 0.118 d 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 h 0.080 0.254 0.003 0.010 l 0.300 0.610 0.012 0.024
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