The UC2845BNG(购买请点击)Bfamily ofcontrolICspto implement off-line or DC to DCfixed frequencycurrent mode control schemes witha minimal external parts count. Internally implementedcircuits includea trimmed oscillator for preciseDUTY under lockoutfeaturingstart-upcurrent less than0.5mA,a trimmed for accuracy at the , alsoprovidescurrent limit control,and a totempole output stage designed to sourceor sink high peakcurrent.Theoutputstage, suitablefor driving N-Channel MOSFETs, is low in the offstate.
Differences between members of this family are theunder-voltagelockout thresholdsandmaximumdutycycle ranges. The haveUVLO thresholds of 16V (on) and 10V (off), ideallysuitedoff-hecorholdsfortheUC3843BandUC3845Bare8.5Vand7.9V. UC2845BNG(购买请点击) can operateto dutycycles approaching 100%. A range of the zero to <50%is obtainedby the UC3844Band UC2845BNG(购买请点击)bytheadditionofan internal toggleflip flopwhich blanksthe output off every otherclock cycle.
Features
TRIMMED OSCILLATOR FOR PRECISE FRE-QUENCY CONTROL OSCILLATOR FREQUENCY GUARANTEED；
AT 250kHz .CURRENT MODE OPERATION TO 500kHz AUTOMATIC FEED FORWARD COMPENSA；
TION LATCHING PWM FOR CYCLE-BY-CYCLEUC2845BNG(购买请点击)；
CURRENT LIMITING INTERNALLY TRIMMED REFERENCE WITH；
UNDERVOLTAGE LOCKOUT .HIGH CURRENT TOTEMPOLEOUTPUT UNDERVOLTAGE LOCKOUT WITH HYSTER；
ESIS LOWSTART-UPANDOPERATINGCURRENTUC2845BNG(购买请点击)。
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