The NCP1280 provides a highly integrated solution for off−line power supplies requiring high−efficiency and low parts count. This voltage mode controller provides control outputs for driving a forward converter primary MOSFET and an auxiliary MOSFET for active clamp circuit. The second output with its programmable delay can also be used for driving a synchronous rectifier on the secondary or for asymmetric half bridge circuits.

FEATUREs
•Internal High Voltage Startup Regulator (25 V to 700 V)
•Dual Control Outputs with Adjustable Overlap Delay
•Programmable Maximum Duty Cycle Control
•Single Resistor Oscillator Frequency Setting
•Fast Line Feedforward
•Line Under/Overvoltage Lockout
•Dual Mode Overcurrent Protection
•Programmable Soft−Start
•Precision 5.0 V Reference
•Pb−Free Package is Available

Typical Applications
•Off−Line Power Converters in 100−500 W Range
•Desktop Power Supplies (High−End)
•Industrial Power Supplies
•Plasma/LCD TV Front−End