Patent ID: 7786810

Claim:
A phase locked loop with a current leakage adjustment function, comprising: a phase locked loop unit having a filter, and generating a control voltage based upon a frequency error and a phase error between a reference clock signal and a feedback signal, wherein the filter has a compensation voltage node and a first leakage current having a first value; and a self-adjusting circuit including: a MOS capacitor generating a second leakage current having a second value being one M th of the first value of the first leakage current based upon the first leakage current, wherein M is a natural number; a current mirror generating a compensation current having a magnitude near M times of the first value of the first leakage current based upon the second leakage current, inputting the compensation current into the compensation voltage node of the filter, and receiving the second leakage current to generate a reference voltage; and a voltage adjusting circuit performing a variety of band switchings when a voltage value at the compensation voltage node is not equal to that of the reference voltage in the current mirror.