Delta Electronics, Inc.

Le-Yang Yang

Jian Zhou

Jin-Fa Zhang

Qi Fu

Dao-Fei Xu

Hai-Bin Song

A converter includes a transformer, a main switch, an active clamping circuit, a synchronous rectifying switch and a processing circuit. The transformer includes a primary winding and a secondary winding. The main switch is coupled to the primary winding. The active clamping circuit clamps the voltage across the main switch when it is OFF. The active clamping circuit includes an auxiliary switch. The synchronous rectifying switch is coupled to the secondary winding. The processing circuit determines whether the rectifying switch is in a main conducting period or a sub conducting period according to a first voltage signal across the rectifying switch and at least one detecting signal from the converter, and generates a driving signal to control the synchronous rectifying switch accordingly.

Flyback converter with a passive clamp

Synchronous rectifier control for a flyback converter with an active clamp

A converter includes a transformer, a main switch, an active clamp circuit, and a control circuit. The transformer includes a primary winding and a secondary winding, and is configured to receive an input voltage and output an output voltage to a load. The main switch is coupled between the primary winding and a primary ground terminal. The active clamp circuit includes an auxiliary switch and a clamp capacitor. The auxiliary switch is coupled to the clamp capacitor in series, and the active clamp circuit is coupled in parallel to the two terminals of the primary winding or the main switch, and is configured to clamp the voltage across the main switch when it is OFF. The control circuit outputs an auxiliary switch control signal to turn on the auxiliary switch when the voltage across the main switch is at its first peak of the resonant voltage.

Converter and control method thereof

Growing community of inventors

Taoyuan, Taiwan

Le-Yang Yang