Adaptive Digitally-Controlled Active Rectifier-Based Receiver for Bioimplants

This paper presents a wireless power transfer (WPT) receiver with an adaptive digitally-controlled on-off delay-compensated active rectifier for high-current biomedical implants. High efficiency is achieved by using adaptive digital techniques to compensate for turn-on and turn-off delays, reduce reverse current, and eliminate multiple pulsing. The adaptive scheme improves voltage conversion ratio (VCR) and power conversion efficiency (PCE) at different PVT corners. The generation of the optimal delay compensation current is 1.5 times faster than published works. The proposed design is implemented with 0.18 μm CMOS process. The measured maximum VCR is 0.978 for a 2 kΩ load resistance, and the maximum PCE is 92.2% for a 200 Ω load resistance.