A charge pump includes a reference charge pump with an input interface to accept a phase detector signal and a duty-cycle feedback signal, and an output to supply a control voltage. A replica charge pump accepts the phase detector signal supplies the duty-cycle feedback signal. If the reference charge pump source current (Ip) becomes mismatched with the sinking current (In), non-equal Tn and Tp time periods may result. The phase detector accepts reference and data signals having a steady state offset error and supplies a non-50% duty cycle square wave phase detector signal. The replica charge pump supplies a duty-cycle feedback signal to the reference charge pump responsive to the non-50% duty cycle phase detector signal and the reference charge pump equalizes the source and sink currents. When the phase detector measures reference and data signals fully orthogonal in phase, it supplies s 50% duty cycle signal.