2012. 08 ver. d copyright g renergy o pto, inc. www.grenergy - ic.com 1 preliminary gr88 18a fe a tures ? primary feedback control without secondary feedback s ignal ? constant - v oltag e(cv) and constant - current(cc) r egulation ? pulse by p ulse current limiting ? low start - u p current (6 ua ) ? fixed 40khz s wit ching frequency for d riving bjt ? built - in soft s tart ? w ide vcc o peration r ange ? vcc over - voltage protection ? output over - voltage protection ? cable compensation for cv r egulat i on ? sot - 26 p ackage , with few external components n eeded application ? low power a dapt e r ? cell phone c harger ? replacement for linear a dapter description the gr88 18a is an excellent pr imary side feedback controller . it ? s integrated constant voltage (cv) and constant current (cc) regulation functions. while it operates on cv mode, it ? s built - in the cable compensation to compensate the voltage dr op of the dc output cable to improve the load regulation. it minimizes the components counts and is available in a tiny sot - 26 package. those make it an ideal design for low cost applications. it provides functions of low startup current, green - mode power - saving operation,. also, the gr88 18a is built - in the vcc o ver - v oltage p rotection and fb pin to prevent the circuit being damaged from the abnormal conditions. ordering and marking informatio n c: sot-26 gr 8818a package code rohs code g: green (halogen free) device l: pb free device code 1 18 a x x x x x serial no. code 2 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 changes to improve reliability or manufacture ability without noti ce, and advise customers to obtain the latest version of relevant information to verify before placing orders. p rimary f eedback pwm c ontroller for f ly back application
2012. 08 ver. d copyright g renergy o pto, inc. www.grenergy - ic.com 2 preliminary gr88 18a pin configuration top view 1 2 3 vcc gnd fb out comp cs 6 5 4 pin description p in no. n ame function 1 vcc power s upply pin 2 gnd ground 3 fb connecting to a resistor divider from aux. winding to ground , the resistor divider ratio determine s the aux. winding and secondary output voltage 4 cs current sense pin, connect to sense the power transistor current 5 com p voltage loop gm error amplifier output , by connecting a n r series with c to gnd to stabilize the control loop 6 out the output driver for driving the external power transistor absolute maximum ratings supply voltage v cc ------------ ---------------- --- ---------- ----------------------- ---------------- - - ----- -------- - ------ 28v com p , fb , cs ---- ---------- ----------------------------- -- ------- ------------------ -------- ----------- ------ ---- --------- - 0.3 ~ 7v ou t ------- -- --------------------------- -------------------------------- ---------- - ------------------ - -------------- - --- ----- - 0 .3 ~ 4.0 v junction t emperature - -------- --------------------------- -------------------------------- -------- -- --- -------------------- 150 c operating a mbient t emperature ---------- -------------- ------------- ------------------------------ --- --- ------ - 20 c to 85 c storage t emperature r ange ---- ---------- --------------------------- --------------------------- -------- --- ----- - 65 c to 150 c package t hermal r esistance (sot - 26) ----------------------- -------------------------- - - ------ - ----- ---- --------- 250 c/w power d issipation (sot - 26, at a mbient t emperature = 85 c) -------------------- ------------------ ---------- 250mw lead temperature (soldering, 10sec) ------------------- ------------- -------------------------------------- -- --- ------- 260 c esd v oltage p rotection, h uman b ody m odel -------------------- -------- ---- ----------------------------- --- ---------- 3.0 kv esd v oltage p rotection, m achine m odel --- ------------------- ------------ ----------------------------------- --- ------- 300 v
2012. 08 ver. d copyright g renergy o pto, inc. www.grenergy - ic.com 3 preliminary gr88 18a r ecommended operating conditions block diagram vcc fb cs leb comp soft start driver out gnd protection uvlo ocp internal power cv/cc control s/h blanking osc cb item min. max. unit supply v oltage vcc 7 20 v
2012. 08 ver. d copyright g renergy o pto, inc. www.grenergy - ic.com 4 preliminary gr88 18a e lectrical c haracteristics ( vcc = 15 v, t a = 25c, unless otherwise specified . ) parameter test co nditions symbol min typ max unit vcc section continuously operating v oltage v op 25 v on t hreshold v oltage v th-on 10.0 1 1.0 1 2.0 v off t hreshold v oltage v th-off 4.5 5.5 6.5 v start - u p c urrent v cc = 9 .5v before uvlo start i cc-st 2 6 10 ua operating s upply c urrent v cc = 15 v, f s = f osc , c l = 1nf i cc-op 0.8 1.5 2.0 ma vcc ovp v ovp 27 28 29.5 v o scillator section normal pwm f requency f osc 38 40 42 khz minimum frequency at no - l oad f osc-n-min 500 hz jitter r ange +/ - 3 % error amplifier out put source current 40 ua output sink current 40 ua minimum output voltage 0.5 v g reen mode start voltage f osc - 1khz 1.8 v c urrent - s ense s ection input impedance z cs 1 m peak c urrent l imitation v csth 1.0 1.1 1.2 v p ropagation delay 150 ns leading - e dge b lanking t ime 500 ns fb pin f eedback input v oltage v fb 1.97 2 2.03 v v fb variation versus vcc d eviation 1 % i nput bias c urrent i bvs - 0.3 - 2 ua fb ovp v fb-ovp 2.4 2.5 2. 6 v out section minimum ba se driving c urrent ibmin 10 ma max imum base driving c urrent ibmax 30 ma rdson pull l ow isink=5ma rds 1 soft s tart t ss 4 m s
2012. 08 ver. d copyright grenergy o pto, inc. www.grenergy - ic.com 5 preliminary gr88 18a application information the gr88 18a is a primary feedback pwm c ontroller for flyback converter application . it is suitable for low output wattage below 5 w and small size ac/dc converter . i t is required only very few external component s to achieve application . t he typical application circuit is shown in below fig.1. vcc ac input emi filter out cs fb gnd comp rb ra rc cc d 1 d 2 n : 1 vout c s r s cb fig.1.
2012. 08 ver. d copyright grenergy o pto, inc. www.grenergy - ic.com 6 preliminary gr88 18a p ackage information sot - 26 symbol sot - 26 millimeters inches min. max. min. max. a 1.45 0.057 a1 0.00 0.15 0.000 0.006 a 2 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 0.12 2 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, protrusions or gate b urrs. mold flash, protrusions or gate burrs shall not exceed 10 mil per side
2012. 08 ver. d copyright grenergy o pto, inc. www.grenergy - ic.com 7 preliminary gr88 18a carrier tape & reel dimensions sot - 26 application a h t1 c d d w e1 f sot - 26 178.0 2 .0 0 50 min. 8.4+2.00 - 0.00 13.0+0.50 - 0.20 1.5 min. 20.2 min. 8.0 0.3 0 1.75 0. 10 3.5 0.05 p0 p1 p2 d 0 d1 t a 0 b 0 k 0 4.0 0.10 4.0 0.10 2.0 0.05 1.5+0.1 0 - 0.0 0 1.0 m in . 0.6 +0. 00 -0. 4 0 3.20 0. 2 0 3.10 0. 2 0 1.50 0. 20 application carrier width cover tape width devices per reel sot - 26 8 5.3 3000
2012. 08 ver. d copyright grenergy o pto, inc. www.grenergy - ic.com 8 preliminary gr88 18a tape and specificati on reel sot 26 direction of feed
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