LEAKAGE COMPENSATION CIRCUIT FOR PHASE-LOCKED LOOP (PLL) LARGE THIN OXIDE CAPACITORS

摘要

Certain aspects of the present disclosure provide methods and apparatus for compensating, or at least adjusting, for capacitor leakage. One example method generally includes determining a leakage voltage corresponding to a leakage current of a capacitor in a filter for a phase-locked loop (PLL), wherein the determining comprises closing a set of switches for discontinuous sampling of the leakage voltage; based on the sampled leakage voltage, generating a sourced current approximately equal to the leakage current; and injecting the sourced current into the capacitor.

主权项

1. A circuit comprising:
a first capacitor; a first transistor having a drain coupled to the first capacitor; an amplifier; a second capacitor; a first set of switches selectively coupled between the first capacitor and the second capacitor; and a second set of switches selectively coupled between an output of the amplifier and a gate of the first transistor.