A Reconfigurable Bidirectional Wireless Power Transceiver for Battery-to-Battery Wireless Charging

Authors

  • T. Santhanakrishnan , V. Kalyanasundaram

Abstract

Battery-to-battery (B2B) wireless charging can take place in many scenarios, such as using a mobile phone to charge
another mobile phone, wearable devices, or low-power sensor node. To facilitate this wireless power transfer (WPT)
function with the minimum additional cost, we propose a monolithic reconfigurable bidirectional WPT transceiver
designed for the first time in CMOS, which can be reconfigured between a differential class-D power amplifier (PA)
and a full-wave rectifier. Meanwhile, we employed a maximum current charging mode (MCCM) to maximize the B2B
charging efficiency, by directly charging the loading battery with the rectifier, and by powering the PA with the
sourcing battery. Then, we reduced the number of cascaded WPT stages from five in the conventional design to three.
This bidirectional WPT transceiver fabricated in 0.35-?m CMOS occupies 3.9-mm
2
of silicon area. The bidirectional
WPT function, verified at 6.78 MHz with only one off-chip capacitor, exhibit speak efficiencies of 91.5%and58.6% for
the receiver and the overall system, respectively, when the output power is1.55W

Published

2020-03-31

Issue

Section

Articles