1W 3.3V-to-16.3V boosting wireless power transfer circuits with vector summing power controller

This paper presents SD card size wireless power transfer system for large volume contactless memory cards. Voltage is boosted simultaneously with power transfer, which eliminates the DC-DC converter or charge-pump circuit for data write operation into the flash memory chip. The proposed approach reduces the number of components and BOM cost and improve the total power efficiency. Vector summing technique is proposed to control the transmitting power and secondary side voltage. The transmitter and rectifier have been designed and fabricated using 0.18μm-CMOS with high voltage option. Voltage boost from 3.3V to 16.3V and 1W power transfer with 50% total efficiency have been successfully demonstrated.