The NCP1282 is a voltage mode controller designed for ac−dc or dc−dc converters requiring high−efficiency and low parts count. This controller incorporates two in phase outputs with an overlap delay to prevent simultaneous conduction and facilitates soft switching. The main output is designed for driving a forward converter primary MOSFET. The secondary output is designed for driving an active clamp circuit MOSFET, a synchronous rectifier on the secondary side, or an asymmetric half bridge circuit.

FEATUREs
•Dual Control Outputs with Adjustable Overlap Delay
•>2.0 A Output Drive Capability
•Soft−Stop Powers Down Converter in a Controlled Manner
•Cycle−by−Cycle Current Limit
•Cycle Skip Initiated if Continuous Current Limit Condition Exists
•Voltage Mode Operation with Input Voltage Feedforward
•Fixed Frequency Operation up to 1.0 MHz
•Bidirectional Frequency Synchronization
•Independent Line Undervoltage and Overvoltage Detectors
•Minimum Operating Voltage of 8.5 V Ensures Enough Voltage is Available for Driving High Voltage MOSFETs
•Accurate Programmable Maximum Duty Cycle Limit
•Programmable Maximum Volt−Second Product
•Programmable Soft−Start
•Internal 500 V Startup Circuit
•Precision 5.0 V Reference
•This is a Pb−Free Device

Typical Applications
•High Power Consumer Electronics
•High Power AC−DC Converters
•High Power DC−DC Converters
•ATX Power Supplies