A Valley Switching Converter generally shows lower EMI and higher power conversion efficiency than a conventional hard-switched converter with a fixed switching frequency. The FSQ-series is an integrated Pulse-Width Modulation (PWM) controller and SenseFET specifically designed for valley switching operation with minimal external components. The PWM controller includes an integrated fixed-frequency oscillator, under-voltage lockout, Leading-Edge Blanking LEB), optimized gate driver, internal soft-start, temperature-compensated precise current sources for loop compensation, and self-protection circuitry. Compared with discrete MOSFET and PWM controller solutions, the FSQ-series reduces total cost, component count, size and weight; while simultaneously increasing efficiency, productivity, and system reliability. This device provides a basic platform for cost-effective designs of valley switching fly-back converters.
Optimized for Valley Switching Converter (VSC)
Low EMI through Variable Frequency Control and Inherent Frequency Modulation
High Efficiency through Minimum Voltage Switching
Narrow Frequency Variation Range Over Wide Load and Input Voltage Variation
Advanced Burst-Mode Operation for Low Standby Power Consumption