Phase detector for automatically controlling offset current and phase locked loop including the same

摘要

A phase detector includes a Gilbert block for outputting a signal proportional to a phase difference between first and second input signals to a first output terminal, and a current source for determining a current in the first output terminal. The current source is controlled by a reference current signal. A converter outputs a current to a second output terminal in response to the signal output from the first output terminal. A variable current source varies the current output to the second output terminal. A controller controls the variable current source in response to the first and second input signals.