Improved Charge Pump with Reduced Reverse Current

Abstract

A highly efficient charge pump that minimizes the reverse charge sharing current (in short, reverse current) is proposed. The charge pump employs auxiliary capacitors and diode-connected MOSFET along with an early clock to drive the charge transfer switches; this new method provides better isolation between stages. As a result, the amount of reverse current is reduced greatly and the clock driver can be designed with reduced transition slope. As a proof of the concept, a 1.1V-to-9.8 V charge pump was designed in a 0.35 mu m 18 V CMOS technology. The proposed architecture shows 1.6 V similar to 3.5 V higher output voltage compared with the previously reported architecture.