UC3843N

The UC3843N is a Current Mode PWM Controller optimized for off-line and DC to DC converters. 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 under-voltage lockout featuring start up current less than 1mA, 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.

• Optimized for off-line and DC to DC converters
• Low start up current (1mA)
• Automatic feed forward compensation
• Pulse-by-pulse current limiting
• Enhanced load response characteristics
• Under-voltage lockout with hysteresis
• Double pulse suppression
• High current totem pole output
• Internally trimmed bandgap reference
• Low RO error amp