题目/Title：A wireless charging circuit with high power efficiency and security for implantable devices

作者/Author：路遥,姜汉钧,麦宋平,王志华
                        Yao Lu,Hanjun Jiang,Songping Mai,Zhihua Wang

会议/Conference：BioCAS 2016

地点/Location：Shanghai, China

年份/Issue Date：2016.17-19 Oct.

页码/pages：pp. 328 - 331

摘要/Abstract：
This paper presents a wireless charging unit (WCU) consisting of a rectifier and a lithium-ion battery charger. It aims at inductively coupled implantable medical applications with wide-range input voltage and light output load. The rectifier promotes power conversion efficiency (PCE) by attenuating multiple pulses caused by dynamic offset-controlled comparator structure and coil resistance; for the battery charger, a ‘modedivision’ control method is proposed to realize smooth and accurate transition from constant current (CC) stage to constant voltage (CV) stage. Furthermore, a ‘state-checking’ operation ensures the security of the whole system. The WCU has been implemented in CSMC 1um high voltage CMOS process. Compared measurement shows that the pulses attenuation structure can raise the rectifier’s PCE from 76.1% to 85.5%; simulation result shows that the proposed charger can control the CC-CV transition process smoothly and properly as expected with an average charging efficiency of 82.26%.