A high-efficiency, low-power wireless power and data frontend for implantable applications

This paper presents a wireless power and data frontend dedicated to implantable applications. It includes a high-efficiency full-wave rectifier with overvoltage protection, a low-power ASK-PPM demodulator and a load shift keying (LSK) modulation circuit. Designed in XFAB 0.6μm HV process, the layout area is 0.3mm*0.4mm. To improve the power conversion efficiency (PCE) of the rectifier, a pair of comparators is adopted to prevent the reverse discharge current. The rectifier achieves power conversion efficiency (PCE) of 92.6% at a carrier frequency of 500 KHz, producing 3.7V DC output across a 1μF∥100Ω load. The ASK-PPM demodulator demodulates the received data at the maximum data rate of 62.5 Kbps, with power consumption of 4.9μA at a supply voltage of 3.3V. The LSK modulation circuit uses the same coils with the rectifier, which simplifies the circuit design and saves area.