Capacitance Distribution in Charge Pumps with Capacitive Load to Reduce Area and Input Energy

This work introduces a novel design strategy for reducing and optimizing the silicon area and input energy of Dickson charge pumps with purely capacitive load. The strategy relies on the sizing of the pumping capacitors using a linear distribution, as counter-imposed to the conventional uniform distribution, which allows up to 75% (90% theoretical) of area saving without altering the transient performance. Theoretical analysis shows that the design strategy leads to the additional advantage of decreasing the input energy, thus relaxing the constraints of the ancillary circuitry. Design guidelines are provided to maximize the achievable improvements. Simulation results using a 65-nm CMOS technology confirm the validity of the proposed approach under various practical scenarios.