FSQ500L: 700V Integrated Power Switch with 130kHz frequency and no bias winding for 2.5W offline flyback converters

The FSQ500L is specially designed for a replacement of linear power supplies with low cost. This device combines current-mode Pulse Width Modulator (PWM) with a senseFET. The integrated PWM controller features include: a fixed oscillator, Under Voltage Lockout (UVLO) protection, Overload Protection (OLP), Leading-Edge Blanking (LEB), an optimized gate turn-on/turn-off driver, Thermal Shutdown (TSD) protection with hysteresis, and temperature-compensated precision-current sources for loop compensation. When compared to a linear power supply, the FSQ500L device reduces total size and weight, while increasing efficiency, productivity, and system reliability. This device provides a basic platform for cost-effective flyback converters

Features

• Single Chip 700V SenseFET Power Switch
• Precision Fixed Operating Frequency: 130kHz
• No-load consumption 250mW at 265V_AC with Burst Mode and Down to 60mW with External Bias
• Internal Startup Switch
• Soft-Start Time Tuned by External Capacitor
• Under-Voltage Lockout (UVLO) with Hysteresis
• Pulse-by-Pulse Current Limit
• Overload Protection (OLP) and Internal Thermal Shutdown Function (TSD) with Hysteresis
• Auto-Restart Mode
• No Need for Auxiliary Bias Winding

Application Notes