A 13.56 MHz Reconfigurable Step-Up Switched Capacitor Converter for Wireless Power Transfer System in Implantable Medical Devices

In this paper we present a reconfigurable, step-up switched-capacitor DC-DC converter for implantable medical devices supplied by a wireless power transfer system (WPT). We target the specifications imposed by WPT based on inductive link, which is the preferred technology for power and data transmission across biological tissues and propose a design methodology to minimize the switch area. The SCC is designed in a commercial CMOS technology using a reduced number of external components to implement the flying and load capacitors. It is capable of self-reconfiguration and self-regulation over the whole 1.4 V - 3.3 V input voltage range. It features four different conversion ratios allow to achieve the desired 5 V output voltage with maximum efficiency.