ZVS half-bridge SMPS design for LCD monitor and LCD-TV

This article presents a zero voltage switching (ZVS) half-bridge converter for an LCD-TV power supply. The asymmetrical pulse-width modulation technique is used in the converter to regulate the dc output voltage and improve the duty cycle utilisation. The transformer leakage inductance and the output capacitance of the active switches are used to resonate the primary current and voltage across the drain to source voltage of active switches in order to achieve ZVS operation. The system analysis of the ZVS half-bridge converter is presented. The operation principle based on mathematical analysis is also provided. The design consideration of the ZVS half-bridge converter is discussed in detail. Finally, the experimental results based on the 24 V/8 A output load and 100 kHz switching frequency are provided to verify the circuit performance.