A low current mismatch and deviation charge pump with symmetrical complementary half-current circuits

Abstract

A full differential charge pump with low current mismatch and deviation is designed in this paper. It adopts two symmetrical complementary P-N replica circuits with half value of the reference current source to remove the current mismatch and deviation. The charging and discharging current are matched very well over a wide output range. The output current mismatch and deviation of the proposed charge pump are less than 0.772% and 0.962% while the output voltage ranges from 0.2V to 1.5V. The good current matching characteristics and low deviation effectively reduce the reference spur of charge pump phase locked loops. The proposed charge pump is implemented with TSMC 0.18μm technology with 1.8V supply. © Springer-Verlag Berlin Heidelberg 2012.