Eliminating the Reverse Charge Sharing Effect in the Charge-Transfer-Switch (CTS) Converter

抄録

A novel voltage level controller for low-power charge pump converters will be presented in this paper. The proposed voltage level controller would react according to the pumped voltage in the charge-transfer-switch (CTS) converter. For the CTS circuit, the pumping operation would be degraded by the charge sharing effect in the auxiliary switch path. In this study, a voltage shifter was used as the voltage level controller to overcome this serious problem without consuming too much chip area. The simulation results showed that the converter can accept a rated input of 1.5V and generated an output up to 8V based on the TSMC 0.35-µm CMOS technology. The layout consumed an area of 125*160µm². The highest output obtained in measuring the real chip was 5.5V which is primarily due to the limitation that the transistor could tolerated. The largest load was estimated as high as 6mW which is large enough for on-chip application.