
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 (VSPWM) 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