A 13.56 Mhz One-Stage High-Efficiency 0x/1x R-3 Rectifier For Implatable Medical Devices

A 13.56 MHz wireless power receiver designed with standard CMOS 0.35 mu m process used for implantable medical devices (IMDs) is presented. By adopting a one-stage 0X/1X reconfigurable resonant regulating (R-3) rectifier, the proposed architecture inherently avoids system voltage conversion ratio (VCR) variation and power conversion efficiency (PCE) degradation problems and thus widens the operation region dramatically. Effects due to the parameters of the coil on the overall system performance are studied and a 50 nH inductor is used in the secondary side to achieve fully on-chip implementation. Based on a synchronized PWM control scheme, the proposed rectifier achieves voltage regulation with only 4 power transistors and 2 gate-driving buffers, which enables compact design and efficient rectification. Meanwhile, the output capacitor can be reduced to 200 nF, while the output voltage is regulated at 3.6 V with less than 100 mV ripple. Simulation results show that the maximum output power is 103.5 mW with efficiency of 91.7%.