Differential charge pump circuit for high speed PLL application

Abstract

A high performance fully differential charge pump with reference voltage circuit was proposed to overcome the inevitable disadvantages in the traditional charge pump circuit, including leakage current, charged/discharge current mismatch and the output ripple. The phase errors and the spurious jump were reduced greatly, and the stability of the output was improved. The characteristics of wide swing range of output and low mismatch rate of currents of the charge pump met the high performance of high speed phase locked loop application requirement.