Design and control of 10-MHz classs E DC-DC converter with reduced voltage stress

This paper presents a novel design method for class E dc-dc converter and a control scheme capable of operating in a wide load range. The class E converter is suitable for several-MHz switching frequency; however, the conventional design has two drawbacks: high voltage stress on the switch (theoretically about 3.6 times the input voltage), and a large input inductor. Here we propose the design scheme to reduce the peak switch voltage up to 2.2-2.5 times the input voltage without additional circuit element and to improve transient performance by a small input inductor. In addition, an on-off control is implemented to regulate the output voltage, allowing the fixed-frequency, fixed-duty-cycle operation and zero voltage switching (ZVS) at light load. Experimental results from a 20-W laboratory prototype operating at 10 MHz verify the feasibility and the effectiveness of the proposed method.