This application note presents a complete design solution for a 2W single-output SMPS using the UC3845B PWM driver and the new STC04IE170 ESBT as main switch. It is associated with the release of the STEVAL-IPB001V1 demo board.
The document details how to design a universal input voltage power supply specifically for ESBT (Enhanced Super Barrier Transistor) based breaker and metering applications. It focuses on the use of the UC3845B PWM driver combined with the STCO4IE170 ESBT as the main switch, utilizing the STEVAL-IPB001V1 demo board as a reference implementation.
Key topics include the design of the flyback stage, managing parasitic capacitances to optimize efficiency and reduce noise, transformer design characteristics, base driving circuit optimization, and an active start-up circuit. The note provides experimental results regarding waveforms and efficiency for various input voltages.
| Output voltage | 24V/83mA |
|---|---|
| Maximum output power | 2W |
| Minimum output power | 0.2W |
| Converter efficiency | 60% |
| Switching frequency | 50kHz |
| Reflected flyback voltage | 150V |
The design is a complete solution for the 2 W single output SMPS widely used as a power supply in breaker applications.
The document describes using the UC3845B PWM driver and the STCO4IE170 ESBT as the main switch.
The rectified minimum input voltage is 150V and the maximum is 1200V.