FSQ100: 650V Integrated Power Switch for 8Watt offline flyback converters

The FSQ100 consists of an integrated Pulse Width Modulator (PWM) and SenseFET, specifically designed for high-performance, off-line, Switch-Mode Power Supplies (SMPS) with minimal external components. This device is an integrated high-voltage power switching regulator that combines a VDMOS SenseFET with a voltage mode PWM control block. The integrated PWM controller features include a fixed oscillator, Under-Voltage Lockout (UVLO) protection, Leading Edge Blanking (LEB), an optimized gate turn-on/turn-off driver, Thermal Shutdown (TSD) protection, and temperature-compensated precision-current sources for loop compensation and fault protection circuitry. When compared to a discrete MOSFET and controller or RCC solution, the FSQ100 device reduces total component count and design size and weight, while increasing efficiency, productivity, and system reliability. This device provides a basic platform well suited for cost-effective flyback converters.

Features

• Internal Avalanche-Rugged SenseFET
• Precision Fixed Operating Frequency: 67KHz
• Burst-Mode Operation
• Internal Startup Circuit
• Pulse-by-Pulse Current Limiting
• Over-Voltage Protection (OVP)
• Overload Protection (OLP)
• Internal Thermal Shutdown Function (TSD)
• Auto-Restart Mode
• Under-Voltage Lockout (UVLO) with Hysteresis
• Built-in Soft-Start
• Secondary-Side Regulation

Application Notes