The Fairchild Power Switch(FPS) product family is specially designed for an off line SMPS with minimal external components. The Fairchild Power Switch(FPS) consist of high voltage power SenseFET and current mode PWM IC. Included PWM controller features integrated fixed oscillator, under voltage lock out, optimized gate turn on/turn off driver, thermal shutdown protection, over voltage protection, and temperature compensated precision current sources for loop compensation and fault protection circuitry. Compared with discrete MOSFET and controller or RCC switching converter solution, the Fairchild Power Switch(FPS) can reduce total component count, design size, and weight and at the same time increase efficiency, productivity and system reliability. It has a basic platform well suited for cost effective monitor power supply.