A 1.5V four phase switched polarity charge pump

A four phase switched polarity charge pump using 0.13 mum triple well CMOS technology is presented. The architecture takes advantage of the threshold voltage cancellation scheme in the conventional four phase Dickson charge pump. With the body control technique, the body effect is eliminated. The charge transfer unit is shared in positive and negative operation, which makes the design more compact. Simulation results show that the proposed 5-stage charge pump can reach +8.22 V/-8.05 V (ideal: +9 V/-9 V) with 10% of total capacitance as estimated parastics, and the output indicates good linearity with respect to the increase of stages.