A design of rectifier for 13.56MHz wireless power transfer receiver with all digital delay-locked loop

This paper proposes a rectifier for the wireless power transfer receiver for medical implant devices. The proposed bridge rectifier uses MOSFET instead of diode. If the output voltage is higher than the input voltage, the reverse current flows and this affects the efficiency. Therefore, we added the reverse current detector that detects the current flowing through the MOSFET and blocks the reverse current. The reverse current detector is designed as all digital delay-locked loop. The proposed rectifier is designed using 0.35um CMOS process. The input voltage is possible up to 3.3V and the rectifier operates at the frequency of 13.56MHz. When the load current is 24mA, the power efficiency is 82.69% and the maximum transferred power transfer is 82.8mW.