Abstract
In the switching power supply, in order to enhance efficiency and the power density of converter, the fixed frequency PWM resonance converter has often been used. It can operate with the constant high frequency, the switch losses are reduced and the system dynamic performance can be improved. But its circuit is complex and the cost is high, it is not very ideal in the low power applications.
This paper introduced an asymmetrical pulse-width-modulation half-bridge DC/DC ZVS converter which is suitable for middle and low power application. This circuit can not only realize zero voltage switching as the main switches in resonance converter, but also adopt constant-frequency PWM control strategy to regulate the output voltage in the wide variational scope of the input voltage and load as the conventional converter.
Key Words: half-bridge; DC/DC converter; soft switch; asymmetrical PWM; flux imbalance
