5MHz PWM-controlled current-mode resonant DC-DC converter with GaN-FETs

Abstract

Abstract-In this paper, a proposed pulse width modulation (PWM) control method for the isolated current-mode resonant DC-DC converter with MHz level switching frequency is presented. The circuit topology is 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. In addition, to achieve the zero-voltage switching (ZVS) operation, phase-shift between primary and secondaryside switches is adapted. The ZVS operation can maintain for primary-side switches. In this paper, proposed technique for achieving stable ZVS operation has been discussed. Some experiments have been done with 5MHz isolated DC-DC converter which has Gallium Nitride field effect transistor (GaN-FET), and the total volume of the circuit is 16.14cm 3 . The data show that the maximum power efficiency is 89.4%.

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

“…Many studies of this circuit topology in MHz level switching operation have been done [7], [10], [14]. [4], [5], [7]- [17].…”

“…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.…”

Low power AC-DC converters for wireless power transfer application

“…There are several modulation techniques that used to be employed in a converter, such as Pulse Width Modulation (PWM) [65][66][67][68][69][70], Pulse Frequency Modulation (PFM) [71][72][73][74][75] and Pulse Skipping Modulation (PSM) [76][77][78][79][80][81][82][83][84][85].…”