DESCRIPTION
The UC384xB family of control ICs provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the offstate.
â TRIMMED OSCILLATOR FOR PRECISE FREQUENCY CONTROL
â OSCILLATOR FREQUENCY GUARANTEED AT 250kHz
â CURRENT MODE OPERATION TO 500kHz
â AUTOMATIC FEED FORWARD COMPENSATION
â LATCHING PWM FOR CYCLE-BY-CYCLE CURRENT LIMITING
â INTERNALLY TRIMMED REFERENCE WITH UNDERVOLTAGE LOCKOUT
â HIGH CURRENT TOTEM POLE OUTPUT
â UNDERVOLTAGE LOCKOUT WITH HYSTERESIS
â LOW START-UP AND OPERATING CURRENT
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