??1qla?|3--?q weltrend semiconductor, inc. s|?????u~??u~afe?? 24 ?1 2 ? 2f, no. 24, industry e. 9 th rd., science - based industrial park, hsin - chu, taiwan tel:886 - 3 - 5780241 fax:886 - 3 - 5794278.57704 19 email:support@weltrend.com.tw ` WT7527 pc power supply supervisor data sheet version 0. 3 0 preliminary release december 29 , 200 4 the information in this document is subject to change without notice. weltrend semiconductor, inc. all rights reserved.
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 2 general description the WT7527 provides protection circuits, power good output (pgo), fault protection latch (fpob), and a protection detector function (psonb) control. it can minimize external components of switching power supply systems in personal compu ter. the over / under voltage detector (ovd / uvd) monitors vs 33, vs 5, vs 12 a and v s12b input voltage level. the over current detector (ocd) monitor is33, is5, is12 a and is12b input current sense. the pin vx provides an extra protection function. when ovd o r uvd or ocd or vx detect the fault voltage level, the fpob is latched high and pgo go low. the latch can be reset by psonb go high. there is 4 ms delay time for psonb turn off fpob. when ovd and uvd and ocd detect the right voltage level, the power good o utput (pgo) will be issue. features the over/under voltage detector (ovd / uvd) monitors vs33 , vs 5, v 12 a and v12b i nput voltage. the over current detector (ocd) monitors is33, is5, is12 a and is12 b input current sense. the vx provide an extra prote ction. both of the power good output (pgo) and fault protection latch (fpob) are open drain output. 75 / 600 ms time delay for uvd / ocd . 300 ms time delay for pgo. 38 ms for psonb input signal de ? bounce. 14 us for ovd internal signal de ? glit ch. 1 m s for uvd internal signal de ? glitch. 20 m s for ocd internal signal de ? glitch. 73 us for pgi internal signal de ? glitch. 4 ms for psonb turn - off fpob. pin assignment and p ackage type pin assignment ordering information package 1 6 ? pin plastic dip 1 6 ? pin plastic so p wt75 27 ? n1 60wt wt75 27 ? s1 60wt lead ? free ?] pb ?^ wt75 27 ? n1 60wt pb wt75 27 ? s1 60wt pb ? the top - side marking would be added a dot ?]??^ in the r ight side for lead - free package. pgi gnd fpob psonb i s 12 a ri is12b vs12b pgo vcc v s 5 v s 33 v s 12 a is33 is5 vx 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 WT7527 - 160
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 3 pin description pin name type description pgi i power good input signal pin gnd p ground fpob o fault protection output pin, open drain output psonb i on/off switch input is12 a i 12v a over current protection sense input ri i current sense adjust inpu t is12 b i 12v b over current protection sense input v s 12 b i 12v b over/under voltage input pin vx i extra protection sense input is5 i 5v over current protection sense input is33 i 3.3v over current protection sense input v s 12 a i 12v a over/unde r voltage input pin v s 33 i 3.3v over/under voltage input pin v s 5 i 5v over/under voltage input pin vcc i power supply pgo o power good output signal pin, open drain output
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 4 block diagram WT7527 - 160 r s q + - + - + - + - + - + - + - + - + - + - + - + - + - + - + - vcc vcci psonb vs33 vs5 vs12a vs12b fpob vx pgo pgi is33 ri is5 is12a is12b 1.2v ~ 1.8v WT7527160 block diagram 75ms / 600ms delay clr 300ms clr delay clr 73us debounce 20ms clr debounce vref = 1.2v v12a iref=vref / ri v12a 1ms clr debounce 14us debounce clr ov 4ms power on reset clr delay 38ms iref * 8 iref * 8 iref * 8 iref * 8 v12a v12a v12a v12a vref = 1.2v un ov power reference internal bandgap osc pwr clk vcci = 3.6v vref = 1.2v pwr pwr debounce un un ov un ov ov
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 5 absolute maximum rat ings parameter min. max. unit supply voltage, vcc, v12 a ? 0.3 16 v pgi , psonb vcc + 0.3 ?] max. 7v ?^ v v s 5 , is5, v s 33 , is33 v12a + 0.3 ?] max. 7v ?^ v input voltage is12a, vs12b, is12b ? 0.3 v12a + 0.3 ?] max. 16v ?^ v output voltage fpob, pgo ? 0.3 7 v operating temperature - 40 12 5 j storage temperature - 55 150 j *note: stresses above those listed may cause permanent damage to the devices recommended operatin g conditions parameter conditions min. typ. max. unit supply voltage, vcc 3.8 5 16 v pgi , psonb, v s 5, v s 33 7 v input voltage v s 12 a, vs12b 16 v output voltage fpob, pgo 7 v fpob 0.3v 10 ma output sink current pgo 0.3v 10 ma output current for ri ri 10 65 ua electrical characteristics, at ta=25 c and v cc =5v . over voltage detection parameter condit ion min. typ. max. unit v s 33 3. 8 3. 9 4.0 v v s 5 5.6 5.8 6. 0 v over voltage threshold v s 12 ab 13.5 13.8 5 14. 2 v i leakage leakage current (fpob) v( fpob ) = 5v 5 ua v ol low level output voltage ( fpob ) i sink = 10ma 0.3 v pgi and pgo parameter con dition min. typ. max. unit v s 33 2.8 2.9 3.0 v v s 5 4. 2 4. 4 4. 6 v v s 12 ab 10.3 10 .65 1 1 . 0 v under voltage threshold vx 1.176 1.20 1.2 24 v input threshold voltage(pgi) 1.176 1.20 1.2 24 v i leakage leakage current(pgo) pgo = 5v 5 ua v ol l ow level output voltage(pgo) i sink = 10ma 0.3 v offset voltage of ocp comparators ? 3 3 mv psonb parameter condition min. typ. max. unit input pull - up current psonb= 0v 150 ua high - level input voltage 1.8 v low - level input voltage 1.2 v
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 6 total device parameter condition min. typ. max. unit icc supply current psonb= 5v 1 ma vcc operation start up voltage 3.2 3.4 3.6 v vcc under lockout voltage 1.8 2.0 2.2 v switching characteri stics , at ta= - 40 j ~125 j parameter condition min. typ. max. unit pgi to pgo delay time t d1 200 300 400 ms t d2 49 75 100 ms short circuit delay time t d2 - 1 392 600 800 ms pgo to fpob d elay time t d3 2 4 6 ms under voltage delay time t d4 0.6 1 1.4 ms over current delay time t d 5 13 20 27 ms over vol tage delay time t d6 9 14 19 us vx delay time t d7 0.6 1 1.4 ms psonb de - bounce time t b 1 24 38 52 ms pgi de - bounce time t b 2 47 73 100 us application circuit WT7527 is12b is33 is5 pgi psonb vcc vs12a vs12b vs33 vs5 vx fpob gnd is12a pgo ri +5vsb r3, 1% +12va 22uf +5v r1, 1% 22uf r4, 1% 22uf +12vb +3.3v 22uf r2, 1% 30k, 1% pgi +5vsb psonb 0.01uf 10k 300 +5vsb +5v 1k
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 7 application note when the current cross inductor raised, inductor voltage raised. an d when inductor voltage exceeded resistor voltage, the ocp active. we can setup ocp point by the following equation let vr = vl r * ir = rl * il ?? ir = 8 * iref r * (8 * vref / ri) = rl * il r = (rl * il) / (8 * vref / ri) ????? (1) and the capacitor c is used to avoide power on fail or dynamic load fail. we suggest c > 1uf. ex ?g how to select the resistor of r ? assume ri=30k [ , rl=5m [ , ocp il=20a ?c sol ?g r = ( il * rl ) / ( 8 * iref ) = ( 20a * 5m [ ) / { 8 * ( 1 . 2 v / 30k [ )} = 312.5 [
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 8 mechanical in formation plastic dual ? in ? line package note 1 ?g all linear dimensions are in inches ?] millimeters ?^ . note 2 ?g this drawing is subject to change without notice. note 3 ?g falls within jedec ms ? 001
WT7527 preliminary release rev. 0 . 3 0 weltrend semiconductor, inc. page 9 plastic small ? outline package note 1 ?g all linear dimensio ns are in inches ?] millimeters ?^ . note 2 ?g this drawing is subject to change without notice. note 3 ?g falls within jedec ms ? 012
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