TOP248YN is a power supply controller IC made by Power Integrations. It belongs to the TOPSwitch-GX family, designed for AC-DC switching power supplies (SMPS). 

It integrates a high-voltage MOSFET + PWM controller + protection circuits in one chip, making it commonly used in TV power boards, adapters, chargers, and SMPS circuits. 

Main Specifications

• Type: Offline AC-DC converter / switcher IC

• Topology: Flyback power supply

• Input voltage: 85–265 VAC

• Breakdown voltage: 700 V

• Output power: up to ≈155–205 W depending on design

• Switching frequency: 66–132 kHz

• Package: TO-220-7 (6 leads)

• Operating temperature: -40 °C to +150 °C 

Key Features

• Integrated 700 V power MOSFET

• Soft-start to reduce stress on components

• Over-temperature, over-voltage, and current-limit protection

• Frequency jittering to reduce EMI noise

• Low standby power consumption

• Can regulate output even with no load