A 13.56 MHz CMOS Active Rectifier With Switched-Offset and Compensated Biasing for Biomedical Wireless Power Transfer Systems

摘要: A full-wave active rectifier switching at 13.56 MHz with compensated bias current for a wide input range wirelessly powered high-current biomedical implants is presented. The four diodes of conventional passive are replaced by two cross-coupled PMOS transistors and comparator- controlled NMOS switches to eliminate diode voltage drops such that high conversion ratio power efficiency could be achieved even low AC amplitude $\vert V_{\rm AC}\vert$ . comparators implemented switched-offset biasing compensate the delays multiple pulsing reverse current. proposed uses modified CMOS peaking source quasi-inversely proportional supply better control over (1.5 4 V). was fabricated in standard 0.35 $\mu{\rm m}$ N-well process area 0.0651 ${\rm mm}^{2}$ For measured AC}\vert=3.0\ {\rm V}$ , ratios 0.89 0.93 $R_{\rm L}=500\ \Omega$ 5 k}\Omega$ respectively, efficiencies 82.2% 90.1% ranges from 1.5 V