Charge pumping circuit using non-overlapping clock control

摘要

A charge pumping circuit generates a negative voltage equal in magnitude to the positive supply voltage. A non-overlapping clock is used to set the voltage across a first capacitor equal to the positive supply voltage through a MOS switch. This stored voltage is then transferred to a second capacitor through a second MOS switch to generate a negative voltage at one terminal of the second MOS switch. The use of MOS switches eliminates the threshold voltage drop if MOS diodes were used to charge the first capacitor or to transfer the voltage from the first capacitor to the second capacitor.