UC2844B
DESCRIPTION under-voltagelockout thresholds and maximum duty The UC384x B family ofcontrol ICs providesthe neccycle ranges. The UC3842B and UC3844B have essary features to implement off-line or DC to DC UVLO thresholds of 16V (on) and 10V (off), ideally fixed frequency current mode control schemes .. with suitedoff-lineapplications Thecorrespondingthresha minimal external parts count. Internally impleoldsforthe UC3843Band UC3845Bare8.5 V and7.9 mented circuits include a trimmed oscillator for pre V. The UC3842B and UC3843B can operate to duty cycles approaching 100%. A range of the zero to < cise DUTY CYCLE CONTROL under voltage lockoutfeaturingstart-up current less than0.5m A,a pre50 % is obtained by the UC3844B and UC3845B by cision reference trimmed for accuracy at the error the addition of an internal toggle flip flopwhich blanks amp input, logicto insure latched operation,a PWM the output off every otherclock cycle. BLOCK DIAGRAM (toggle flip flop used only in UC3844B and UC3845B)
Vi 7...
Representative UC2844B image (package may vary by manufacturer)
