A novel mixed-structure design for high-efficiency charge pump

In this paper, a novel low-power high-efficiency switching-capacitor DC-DC voltage converter based on the combination of static CTS (Charge-Transfer-switch) charge pump and cross-coupled charge pump is presented. At this time, some motivated methods to overcome both the reverse charge sharing problem of traditional static CTS charge pump and the problem of threshold drop at the output stage are proposed. The charge pump proposed can operate at 1 MHz switching-frequency on the 0.1 muF pump-capacitors. After the simulation by using HSPICE 0.35 mum TSMC process, our work can pump the input low DC- voltage (1.5 V) up near to 5 times of it (7.5 V) and the pumping-gain reaches to 95%, a great achievement has been obtained. And the real chip is in experimenting. At present, the characteristic of the prototyping chip implemented by the TSMC is under measuring.