This document introduces the design of a half-bridge LLC resonant converter using Fairchild Semiconductor's FSFR series power switch (FPS™). By operating at high frequency and utilizing resonant switching technology, it is possible to reduce the size of passive components and switch losses, achieve soft switching, and improve efficiency.
The document provides an overview of the AN-4151SC LLC resonant converter, explaining its principle of operation, the role of the resonant tank, and the benefits of using an LLC topology for high‑efficiency power conversion. It also outlines the typical circuit topology, including the rectifier, resonant tank, and filter components.
Further sections discuss practical design issues such as integrated transformer design, selection of operating mode for maximum gain, and specific features of the FSFR product series. A reference design example with a 400 VDC input and 24 V/192 W output is presented, along with performance graphs and guidelines for achieving zero‑voltage‑switching (ZVS) operation. This manual is written in Japanese.
| Input Voltage | 400 VDC |
|---|---|
| Output Voltage | 24 V |
| Output Power | 192 W |
| Switching Frequency | 100 kHz |
It provides design considerations, operating mode guidance, and performance data for the AN-4151SC LLC resonant converter.
The note recommends a 400 VDC input and a 24 V output delivering up to 192 W of power.
The integrated transformer determines the resonant tank values and influences the converter’s gain and ZVS performance.