UC3845BN

The UC3845BN is a high performance current mode PWM Controller IC. It is 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 off-state.

• Trimmed oscillator for precise frequency control
• Automatic feed forward compensation
• Latching PWM for cycle-by-cycle current limiting
• Internally trimmed reference with under-voltage lockout
• High current totem pole output
• Under-voltage lockout with hysteresis
• Low start-up and operating current