Fully differential charge pump with switched-capacitor common-mode feedback

摘要

Certain aspects of the present disclosure provide methods and apparatus for implementing a fully differential charge pump circuit that eliminates a source of noise and power consumption by using a low-noise switched-capacitor common-mode feedback (CMFB) circuit, rather than a continuous-time amplifier-based CMFB circuit. The fully differential charge pump circuit presented in this disclosure includes the switched-capacitor CMFB (SC-CMFB) unit connected to differential output nodes of the charge pump and provides a feedback signal to the charge pump to control a common-mode voltage of the differential signals based on a reference common-mode voltage. In certain aspects, a replica phase-frequency detector (PFD), a frequency divider, and a non-overlapping clock generator provides control signals for the SC-CMFB circuit.