Introduction
This document describes a 15-W flyback switched mode power supply (SMPS) application that uses an emitter-switched bipolar transistor (ESBT™) switch (STC03DE220HV) and L6565 quasi-resonant pulse-width modulation (PWM) controller.
The application is a universal, cost-effective flyback converter used in metering applications, with an excellent wide-voltage input range from 125 to 1250 VDC, achieved using the ESBT as the main switch and a quasi-resonant PWM driver.

Adapter features
Main characteristics
The following is a list of the specifications and main parameters of the demonstration board.
● Minimum input voltage: 125 VDC
● Maximum input voltage: 1250 VDC
● Output voltage: 5 V - 3.0 A
● Maximum output power: 15 W
● Short-circuit protection based on auto-restart feature
● Minimum switching frequency limited to 30 kHz
● Overall converter efficiency > 60%
● Non-galvanic isolated solution used in most metering applications
● PCB type and size:
   – material used for PCB: FR-4
   – double-sided layout
   – thickness of copper: 35 µm
   – total diameter of demonstration board: 58 x 120 mm.