High frequency PWM-controlled current-mode resonant DC-DC converter with boost conversion

Abstract

In this paper, a new pulse width modulation (PWM) control method for the isolated current-mode resonant converter with a fixed switching frequency is presented. The circuit topology is the same as a conventional resonant converter with synchronous rectification and without any additional components. The control technique for the output voltage regulation is proposed with the unique PWM control for synchronously-rectifying switches. By using the transformer's leakage inductance and the PWM control, the boost conversion can be realized. Also, the zero-voltage switching (ZVS) operation can be done for primary switches, simultaneously. Some experiments have been done with 5MHz isolated DC-DC converter which has Gallium Nitride field effect transistor (GaN-FET).

Five-Megahertz PWM-Controlled Current-Mode Resonant DC–DC Step-Down Converter Using GaN-HEMTs

“…Therefore, a 5MHz switching frequency, which is relatively high for isolated DC-DC converters, is adopted in this research [3]- [5]. However, by adopting a high switching frequency, power loss such as switching loss and gate driving loss increases.…”