A CMOS 0.8 /spl mu/m programmable charge pump for the output stage of an implantable pacemaker

This work proposes a voltage multiplier suitable for a pacemaker pulse generator in a high voltage 0.8 /spl mu/m CMOS technology. The proposed circuit topology can handle the relatively high voltages required to stimulate the heart, while still being able to operate from an almost exhausted pacemaker battery. The circuit can operate with a supply voltage from 2.8 V to 2 V, while the maximum output voltage is about three times the power supply. Fine programmability of the output voltage has been achieved, thus allowing the choice of the optimum trade-off between stimulation efficacy and battery longevity. Moreover the proposed solution takes care of minimizing the parasitic coupling and disturbances between the charge pump and other blocks in the system.