Programmable current source adjustment of leakage current for phase locked loop

摘要

A method and apparatus for post-fabrication adjustment of a phased locked loop leakage current is provided. The adjustment system includes a programmable current source that adjusts a leakage current offset circuit to compensate for the leakage current of a capacitor. The capacitor connects to a control voltage of the phase locked loop. The programmable current source includes at least one current source and switch to adjust the leakage current offset circuit. The programmable current source is selectively adjusted by a combinational logic circuit. Such control of the leakage current in the phased locked loop allows a designer to achieve a desired phase locked loop operating characteristic after fabrication of the adjustable phase locked loop.