
Fairchild Semiconductor
Description
A Valley Switching Converter (VSC) generally shows lower EMI and higher power conversion efficiency than a conventional hard-switched converter with a fixed switching frequency. The FSQ510 (H or M) is an integrated valley switching pulse width modulation (VS PWM) controller and SenseFET specifically designed for offline switch-mode power supplies (SMPS) for valley switching with minimal external components. The VS-PWM controller includes an integrated oscillator, under-voltage lockout (UVLO), leading-edge blanking (LEB), optimized gate driver, internal soft-start, temperature-compensated precise current sources for loop compensation, and self-protection circuitry.
FEATUREs
■ Uses an LDMOS Integrated Power Switch
■ Optimized for Valley Switching Converter (VSC)
■ Low EMI through Variable Frequency Control and Inherent Frequency Modulation
■ High Efficiency through Minimum Drain Voltage Switching
■ Extended Valley Switching for Wide Load Ranges
■ Small Frequency Variation for Wide Load Ranges
■ Advanced Burst-Mode Operation for Low Standby Power Consumption
■ Pulse-by-Pulse Current Limit
■ Protection Functions: Overload Protection (OLP), Internal Thermal Shutdown (TSD) with Hysteresis
■ Under-Voltage Lockout (UVLO) with Hysteresis
■ Internal Startup Circuit
■ Internal High-Voltage SenseFET: 700V
■ Built-in Soft-Start: 5ms
APPLICATIONs
■ Auxiliary Power Supplies for LCD TV, LCD Monitor, Personal Computer, and White Goods