FSL127H

FSL127H — Green Mode Fairchild Power Switch (FPS™) September 2010 FSL127H Green Mode Fairchild Power Switch (FPS™) Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Built-in 5ms Soft-Start Function Internal Avalanche-Rugged 700V SenseFET Low Audio Noise High-Voltage Startup Fixed PWM Frequency at 100KHz Linearly Decreasing PWM Frequency to 18KHz Peak-Current-Mode Control Cycle-by-Cycle Current Limiting Leading-Edge Blanking (LEB) Synchronized Slope Compensation Internal Open-Loop Protection (OLP) VDD Under-Voltage Lockout (UVLO) VDD Over-Voltage Protection (OVP) Constant Power Limit (Full AC Input Range) Internal OTP Sensor with Hysteresis Description The highly integrated FSL127H consists of a current mode Pulse Width Modulator (PWM) and an avalancherugged 700V SenseFET. It is specifically designed for high-performance offline Switch Mode Power Supplies (SMPS) with minimal external components. The integrated PWM controller features include a proprietary green-mode function that provides off-time modulation to linearly decrease the switching frequency at light-load conditions to minimize standby power consumption. To avoid acoustic noise problems, the minimum PWM frequency is set above 18KHz. This green-mode function enables the power supply to meet international power conservation requirements. With the internal high-voltage startup circuitry, the power loss due to bleeding resistors is also eliminated. To further reduce power consumption, the PWM controller is manufactured using th...