HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
.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-CYCLE
.CURRENT LIMITING INTERNALLY TRIMMED REFERENCE WITH
.UNDERVOLTAGE LOCKOUT .HIGH CURRENT TOTEMPOLEOUTPUT UNDERVOLTAGE LOCKOUT WITH HYSTER.
ESIS LOWSTART-UPANDOPERATINGCURRENT
DESCRIPTION
TheUC384xBfamily ofcontrolICsprovidesthenecessary
features to implement off-line or DC to DC
fixed frequencycurrent mode control schemes with
a minimal external parts count. Internally implemented
circuits includea trimmed oscillator for precise
DUTY CYCLE CONTROL under voltage lockoutfeaturingstart-
upcurrent less than0.5mA,a precision
reference trimmed for accuracy at the error
ampinput, logicto insurelatchedoperation,a PWM