A programmable charge pump voltage converter for implantable medical devices in a HV technology

In this paper, a multi-channel, 5bit programmable charge-pump voltage multiplier aimed at charging the output capacitors for the delivery of voltage stimuli in implantable devices, is presented. The circuit was fabricated in a 0.6μm HV-CMOS technology and tested, showing a measured charge efficiency close to 95% of the maximum theoretical value. The individual charge pump channels share the pump capacitors and can be programmed as IX, 2X, or 3X multiplier. The circuit is capable to operate with a battery ranging from 1.6V to 5.5V.