A ZVS active diode rectifier for wireless power transmission using voltage-time-conversion DLL

Abstract

A CMOS active diode rectifier with voltage-time conversion (VTC) delay locked-loop (DLL) circuit is proposed to achieve zero-voltage switching (ZVS) operation for an efficient wireless power transmission system. The proposed VTC DLL can achieve stable ZVS under process variations. The proposed circuit is implemented in a standard 0.18um CMOS process using 3.3V I/O MOSFETs. The maximum power conversion efficiency of 78% is obtained at 39mW output.