Efficient CMOS rectifier for inductively power-harvested implants

A fully integrated CMOS rectifier, intended for inductively powered electronic implants and featuring ultra-low-loss characteristic, is presented. By making use of highperformance active diodes fulfilling almost ideal switching (zero forward voltage drop) and circuit to be provided with negative resistance, the proposed design is able to achieve an maximum conversion efficiency of more than 90% when designed in a 0.18-µm standard CMOS process, without any special device requiring additional manufacturing procedures. As a result, the proposed design dramatically reduces the production cost. Estimations in all aspects regarding the performance of the rectifier are given in this paper.