A Full Differential Charge Pump Based on Symmetrical Complementary Half-Current Circuit Architecture

Q. Huang, W. Zhao, W. Wang, W. Wu, C. Du, Z. Feng, J. He, P. He, L. Song
Peking University Shenzhen SOC Key Laboratory,
China

Keywords: charge pump, differential charge pump, mismatch, deviation, symmetrical complementary replica circuits,

Summary:

A full differential charge pump with low current mismatch and deviation is designed in this paper based on the symmetric complementary half-current circuit architecture. 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 maximum output current mismatch and deviation of the proposed charge pump are 0.78% and 0.97% over the output voltage range from 0.2V to 1.5V, respectively. 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 in 0.18μm CMOS technology with 1.8V supply.