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2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 1 GR8835A features current mode pwm very low startup current under-voltage lockout (uvlo) non-audible-noise green-mode control programmable switching frequency cycle-by-cycle peak current limiting internal leading-edge blanking internal slope compensation internal 4ms soft start (fs=65khz) vcc over voltage clamp gate output voltage clamp soft driving for reducing emi over-voltage protection (ovp) on vcc pin over-load protection (olp) over-current protection (ocp) on cs pin 300ma driving capability meet the standard of green partner, sony ss-00259 applications switching ac/dc power adapter and battery charger open-frame smps description the GR8835A is a highly-integrated, low startup current, current mode pwm controller with green-mode function. this function enables the power supply to easily meet even the strictest power conservation requirements. the integrated functions also include the leading-edge blanking of the current sensing, internal slope compensation, cycle-by-cycle peak current limiting and soft start. olp, ocp and ovp provide protection performance for fault conditions. to protect the external power mosfet from being damaged by supply over voltage, the GR8835A gate voltage is clamped about 13v. the GR8835A improves the performance and reduces the cost of power supplies. it is with bot h 8-pin dip and 6-pin sot-26 package. ordering and marking information dip-8 sot-26 code 1 8 9 a b g h i j year 2008 2009 2010 2011 2016 2017 2018 2019 code 2 1 2 3 4 9 a b c month jan. feb. mar. apr. sep. oct. nov. dec. grenergy opto inc. reserves the right to make chang es to improve reliability or manufacture ability wi thout notice, and advise customers to obtain the latest v ersion of relevant information to verify before pla cing orders. green-mode pwm controller with integrated protectio ns
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 2 GR8835A pin configuration pin description pin no. name function 1 gnd ground 2 comp voltage feedback pin, by connecting a photo- coupler to control the duty cycle 3 rt connecting a resistor to ground, this resistor determine the switching frequency 4 cs current sense pin, connect to sense the mosfet current 5 vcc power supply pin 6 out the output driver for driving the external mo sfet note: pin no. is only for sot-26 package. absolute maximum ratings supply voltage vcc ------------------------------- --------------------------------------------------- ----------------------- 32v comp, rt, cs ------------------------------------- --------------------------------------------------- --------------- 0.3 ~ 7v junction temperature ----------------------------- --------------------------------------------------- --------------------- 150 operating ambient temperature --------------------- --------------------------------------------------- --------- 40 ~ 85 storage temperature range ------------------------ --------------------------------------------------- ----- 65 ~ 150 sot-26 package thermal resistance ---------------- --------------------------------------------------- ----------- 250 /w power dissipation (sot-26, at ambient temperature = 85 ) ----------------------------------------------- 250mw power dissipation (dip-8, at ambient temperature = 85 ) ------------------------------------------------ ---- 650mw lead temperature (all pb free packages, soldering, 10 sec) ------------------------------------------ -------- 260 esd voltage protection, human body model --------- --------------------------------------------------- ------------- 3kv esd voltage protection, machine model ------------ --------------------------------------------------- --------------- 250v
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 3 GR8835A recommended operating conditions item min. max. unit supply voltage vcc 11 25 v switching frequency 50 130 khz block diagram internal bias & vref vcc ok all blocks 15v/9v uvlo ovp 28v 3.6v olp protection en debounce leb s q r 60ms delay 0.95v soft start 0.9v ocp vbias osc vref ok driver stage en protection en cs open, 2ndary rectify diode short mode select rt open/short slope compensation rt_f rt_f latch rb low pass filter
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 4 GR8835A electrical characteristics (t a = +25 unless otherwise stated, v cc = 15.0v) parameter pin min. typ. max. unit supply voltage startup current 5 8 20 ua operating current (with 1nf load on out pin), vcomp = 0v 5 2.0 3.0 ma operating current (with 1nf load on out pin), vcomp = 2.5v 5 2.5 ma operating current (with 1nf load on out pin), prote ction tripped (olp, ovp) 5 0.5 ma uvlo(off) 5 8.0 9.0 10.0 v uvlo(on) 5 14.0 15.0 16.5 v ovp level on vcc pin 5 26.5 28 29.5 v voltage feedback short circuit current, vcomp = 0v 2 1.5 2.2 ma open loop voltage, comp pin open 2 5.4 v green-mode threshold voltage 2 1.65 v current sensing maximum input voltage, vcs (off) 4 0 .85 0.9 0.95 v leading edge blanking time 4 350 ns input impedance 4 1 m delay to output 4 100 ns oscillator frequency (rt = 100k ) 3 60 65 70 khz green mode frequency (rt = 100k ) 3 20 khz temp. stability ( 40c ~ 110c) 3 3 % voltage stability (vcc = 11v ~ 25v) 3 3 % gate driver output output low level, vcc = 15v, io = 20ma 6 1 v output high level, vcc = 15v, io = 20ma 6 8 v rising time, load capacitance = 1000pf 6 350 ns falling time, load capacitance = 1000pf 6 80 110 ns vgate-clamp (vcc = 25v ) 6 13 v olp olp trip level, vcomp (olp) - 3.6 v olp delay time (note), fs = 65khz - 60 ms note: pin no. is only for sot-26 package.
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 5 GR8835A typical performance characteristics fig.3
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 6 GR8835A typical performance characteristics (cont.) ocp (v) temperature ( c) fig. 9 ocp (v) vs. temperature - 40 0 40 80 120 125 0.84 0.86 0.88 0.90 0.92 0.94
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 7 GR8835A application information start-up current the typical start-up current is 8ua. very low start-up current allows the pwm controller to increase the value of start-up resistor and then reduce the power dissipation on it. under-voltage lockout (uvlo) a hysteresis uvlo comparator is implemented in GR8835A, then the turn-on and turn-off thresholds level are fixed at 15v and 9v respectively. this hysteresis shown in fig.13 ensures that the start-u p capacitor will be adequate to supply the chip durin g start-up. fig.13 soft start during initial power on, the GR8835A provides soft start function. it effectively suppresses the star t up peak current to reduce the power mosfet drain voltage especially at high line. oscillator the maximum duty-cycle of internal oscillator is limited about 75% to avoid the transformer saturation. the frequency of the oscillator is decided by an external resistor connected from rt pin to ground. fosc= 6500khz/r (kohm) where r is the resistor connected at rt pin. a 100kohm resistor results in 65khz switching frequency. the recommended range of oscillation frequency is 50 khz~130 khz . green-mode operation when the load decreases to an extent, the frequency of the controller will decrease so as to reduce the system power consumption. the minimum frequency is about 20 khz, which is outside the audio range . leading-edge blanking (leb) each time the power mosfet is switched on, a turn-on spike will inevitably occur at the sense resistor. to avoid fault trigger, a 350ns leading-e dge blanking time is built in. conventional rc filteri ng can therefore be omitted. during this blanking period, the current-limit comparator is disabled an d can not switch off the gate driver. internal slope compensation a built-in slope compensation circuit is constructe d in GR8835A. when the switch is on, a ramp voltage is added to the sensed voltage across the cs pin, which helps to stabilize the system and prevent sub-harmonic oscillations . over-load protection (olp) the controller has over load protection function. an internal circuit detects the load level, when th e load is larger than a threshold and the condition lasts more than 60ms, the gate output will keep low level. then vcc decreases below uvlo off level, the controller resets again. fig.14 shows the waveform of the olp operation.
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 8 GR8835A ovp (over voltage protection) on vcc to prevent power mosfet from being damaged, the GR8835A is implemented an ovp function on vcc. when the vcc voltage is higher than the ovp threshold voltage, the output gate driver circu it will be shut down immediately to stop the switching of power mosfet. the vcc ovp function is an auto-recovery type protection. if ovp happens, the pulses will be stopped and recover at the next uvlo on. the GR8835A is working in a hiccup mode. gate clamp/soft driving driver is clamped by an internal 13v zener diode. those damages usually come from undesired over-voltage gate signals. under the conditions listed below, the gate output will turn off immedia tely to protect the power circuit. the GR8835A also has soft driving function to minimize emi. fault protection there are several critical protection integrated in the . cs pin floating . rt pin floating green-mode operation without acoustic noise when the load decreases to an extent, the switching frequency of the controller will decrease so as to reduce the system power consumption. the minimum frequency is around 20 khz which is outside the audio noise range. fig.15 is the relati on between switching frequency and comp pin voltage. when load reduce to light load, the comp pin voltage will also down to lower level. while comp pin voltage down to 0.8v the controller will shut down the out pin to stop transfer the energy to secondary. then the comp pin will rise slowly due to no working of controller. if comp pin rises to 0 .9v, the controller will start to switch again. this is called the burst mode operation on light load for improving the light load efficiency. when comp pin between 1.1v to 1.65v, the switching frequency is operating from 20khz to 65khz. this section is called the linearly decreasing frequency mode for improving the medium load efficiency. fig.15 . rt pin short to ground
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 9 GR8835A typical application circuit
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 10 GR8835A bom list no. part.no description note 27 r2 smd1206 / 105 28 r3 smd1206 / 754 29 r4 smd1206 / 754 30 r5 smd1206 /393 31 r6 smd1206 / 683 32 r7 smd0805 / 103 33 r8 smd0805 / 10r 34 r9 smd0805 / 68r 35 r10 smd0805 / 1003 1% 36 r11 smd1206 / 2.7r 5% 37 r12 smd1206 / 2.7r 5% 38 r13 smd1206 / 3.9r 5% 39 r14 smd1206 /22r 40 r15 smd1206 /22r 41 r16 smd0805 / 102 42 r17 n.a. 43 r18 smd0805 / 393 44 r19 smd0805 / 153 1% 45 r20 smd0805 / 392 1% 46 r21 n.a. 47 t1 ee25 1.4mh 48 tvr1 07471 49 u1 gr8835/35a sot-26 50 u2 pc123 51 u3 gl431 no. part.no description note 1 c1 x-cap/0.22uf 2 c2 e-cap 400v/33uf 3 c3 102/1kv 4 c4 e-cap 50v/10uf 5 c5 y-cap cd222 6 c6 smd0805, 200v/222 7 c7 e-cap 25v/330uf 8 c8 e-cap 25v/330uf 9 c9 e-cap 25v/100uf 10 c10 smd0805,103 11 c11 n.a. 12 cr1 her108 13 cr2 her108 14 cr3 her108 15 cr4 her108 16 cr5 fr107 17 cr6 fr104 18 cr7 sb5100 19 cr8 n.a. 20 f1 250v/1.5a 21 hs1 heat sink 22 l1 grt160905f403-n 40mh 23 l2 gr0315-1r6m-n 1.6uh 24 ntc1 2.5 7 25 q1 khb4d5n60f 26 r1 smd1206 / 105
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 11 GR8835A package information symbol sot-26 millimeters inches min. max. min. max. a 1.45 0.057 a1 0.00 0.15 0.000 0.006 a2 0.90 1.30 0.035 0.051 b 0.30 0.50 0.012 0.020 c 0.08 0.22 0.003 0.009 d 2.70 3.10 0.106 0.122 e 2.60 3.00 0.102 0.118 e1 1.40 1.80 0.055 0.071 e 0.95 bsc 0.037 bsc e1 1.90 bsc 0.075 bsc l 0.30 0.60 0.012 0.024 0 o 8 o 0 o 8 o note : 1. followed from jedec to-178 ab. 2. dimension d and e1 do not include mold flash, pr otrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 10 mil per side.
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 12 GR8835A package information symbol dip-8 millimeters inches min. max. min. max. a 5.33 0.210 a1 0.38 0.015 a2 2.92 4.95 0.115 0.195 b 0.36 0.56 0.014 0.022 b2 1.14 1.78 0.045 0.070 c 0.20 0.35 0.008 0.014 d 9.01 10.16 0.355 0.400 d1 0.13 0.005 e 7.62 8.26 0.300 0.325 e1 6.10 7.11 0.240 0.280 e 2.54 bsc 0.100 bsc ea 7.62 bsc 0.300 bsc eb 10.92 0.430 l 2.92 3.81 0.115 0.150 note : 1. followed from jedec ms-001 ba 2. dimension d, d1 and e1 do not include mold flash or protrusions. mold flash or protrusions shall not exceed 10 mil.
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 13 GR8835A carrier tape & reel dimensions sot-26 application a h t1 c d d w e1 f sot-26 178.0 2.00 50 min. 8.4+2.00 -0.00 13.0+0.50 -0.20 1.5 min. 20.2 min. 8.0 0.30 1.75 0.10 3.5 0.05 p0 p1 p2 d0 d1 t a0 b0 k0 4.0 0.10 4.0 0.10 2.0 0.05 1.5+0.10 -0.00 1.0 min. 0.6+0.00 -0.40 3.20 0.20 3.10 0.20 1.50 0.20 (mm) application carrier width cover tape width devices per reel sot -26 8 5.3 3000
2011.02. ver 1.5 copyright grenergy opto, inc. www. grenergy-ic.com 14 GR8835A taping direction information sot-26 grenergy opto, inc. reserves the right to make corr ections, modifications, enhancements, improvements, and other changes to its products and services at any time and to dis continue any product or service without notice. cus tomers should obtain the latest relevant information before placing orders a nd should verify that such information is current a nd complete. aaa aaa aaa aaa aaa aaa aaa direction of feed direction of feed

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