STMicroelectronics | UC3844BD1013TR

The UC3844BD1013TR is a high performance current mode PWM controller.

This device 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 0.5 mA, 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.

Features:

• Trimmed oscillator for precise fre-quency control
• Oscillator frequency guaranteed at 250khz
• Current mode operation to 500khz
• Automatic feed forward compensation
• Latching pwm for cycle-by-cycle current limiting
• Internally trimmed reference with undervoltage lockout
• High current totem pole output
• Undervoltage lockout with hysteresis
• Low start-up and operating current