Solid-state power switch Fairchild Semiconductor

General Description

A Quasi-Resonant 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 quasi-resonant operation and Alternating Valley Switching. The PWM controller includes an integrated fixed-frequency oscillator, Under-Voltage Lockout, Leading- Edge Blanking, optimized gate driver, internal softstart, temperature-compensated precise current sources for a loop compensation, and self-protection circuitry. Compared with a discrete MOSFET and PWM controller solution, the FSQ-series can reduce total cost, component count, size, and weight; while simultaneously increasing efficiency, productivity, and system reliability. This device provides a basic platform that is well suited for cost-effective designs of quasi-resonant switching flyback converters

Features

- Optimized for Quasi-Resonant Converter
- Low EMI through Variable Frequency Control and AVS
- 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
- Simple Scheme for Sync Voltage Detection
- Pulse-by-Pulse Current Limit
- Various Protection functions: Overload Protection, Over-Voltage Protection, Abnormal Over-Current Protection (AOCP), Internal Thermal Shutdown with Hysteresis, Output Short Protection
- Under-Voltage Lockout with Hysteresis
- Internal Start-up Circuit
- Internal High-Voltage Sense FET (650V)
- Built-in Soft-Start (15ms)