dimension (units : mm) description applications features dc/dc converter+reset 1) synchronous rectification enables high ef ficiency 2) built-in charge pump circuits for operating output power mos 3) built-in variable reset circuit 4) built-in power mos t r requires fewer external components 5) mute circuit built-in 6) built-in thermal shut down circuit 7) ssop-b16 package has a smaller board footprint the BH6557FV is a variable output dc/dc converter ic with reset. the dc/dc converter output voltage value and reset voltage value can be adjusted by external resistance. ssop-b16 BH6557FV 99w134a cd-rom january , 2000 power mos supply voltage control circuit supply voltage pre driver supply voltage output current from dsw terminal absolute maximum ratings (t a=25 ? c ) parameter operating temperature range storage temperature range power dissipation * 1 derating : 4.5mv/ ? c for operation above t a=25 ? c . on less than 3% (percentage occupied by copper foil), 70mm 70mm, t=1.6mm, glass epoxy mounting. * 2 intermittent current at maximum applied time of 5msec, 1/10 duty (max.) powvcc prepcc vg(9pin) iswomax symbol pd t opr t stg v v v a limits 9 9 * 2 ~ 30 + 85 55 12 1 560 * 1 ~ unit mw ? c ? c + 150
application circuit v unit v v ? c ma v v v 4.5 5.0 t yp. 10.0 5.0 25 300 ? ? ? 5.5 max. 1 1.5 5.5 70 500 vcc vcc vcc-1 symbol min. 8.0 prevcc 4.5 e 10 ? 1.25 vthrst 1 3.5 powvcc vg(9pin) t a 1.7 vdd io (v ariable dc/dc) vthrst 2 current in standby mode quiescent current ei terminal threshold voltage eo terminal output voltage h eo terminal output voltage l dsw terminal on resistance h dsw terminal on resistance l charge-pump output voltage reset detection threshold voltage ist icc veith veoh veol rdswonh rdswonl vg vdet on a ma v v v ? ? v v ce=0v (5 ? c 2 t a 2 75 ? c : design guaranteed ) ieo= e 100 a ieo=100 a il=500ma il= e 500ma operating conditions unit 290 2.60 1.30 1.88 0.15 0.87 0.60 1 1.7 1.30 170 1.45 1.25 1.68 0.01 0.42 0.30 9.7 1.25 ? ? 1.20 1.48 ? ? ? 7.7 1.20 symbol min. t yp. max. parameter power mos supply voltage (unless otherwise noted, t a=25 ? c , prevcc=5v) recommended operating conditions (t a=25 ? c ) electrical characteristics parameter pre-driver supply voltage control circuit supply voltage ambient temperature v ariable dc/dc converter output current reset threshold voltage range 2 reset threshold voltage range 1 v ariable dc/dc converter output voltage * 3 * 4 * 5 * 6 4 l=47 h , c=47 f is used. * * * * 3 in case supply voltage provided outside without using charge-pump built-in. 5 setting voltage range when 12pin(prevcc) is monitored. 6 setting voltage range when the desired voltage except 12pin(prevcc) is monitored.
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