A low voltage CMOS rectifier for low power battery-less devices

Abstract

This paper presents a low voltage CMOS full-wave rectifier for transcutaneous power transmission in low power battery-less devices such as biomedical implants. By using a simple comparator-controlled switch which needs a small supply voltage, the lowest input voltage amplitude can be reduced to 0.7V with a standard CMOS 0.18µm process. With only one comparator, the proposed design dramatically reduces the power loss and the production cost. In combination with current offset which minimize the reverse current of the rectifier under different input amplitudes, the proposed rectifier can achieve a maximum peak voltage conversion efficiency of more than 93% and a power efficiency of approximately 87%.