Patent ID: 9722832
Date: 2017-08-01
CPC Classifications: H03L,H04L

Claim:
1. A frequency control circuit, adapted to be utilized in a phase locked loop circuit, the frequency control circuit comprises: a first frequency control block, configured to generate a first control signal according to a frequency of an output signal from the phase locked loop circuit, wherein the first control signal is configured to control the frequency of the output signal located within a predetermined frequency region, wherein the first frequency control block comprises: a second frequency control block, configured to generate a second control signal according to a frequency of an input signal and the frequency of the output signal, wherein the second control: signal is configured to control the frequency of the output signal located at a target frequency; a pump control unit, electrically coupled with the first frequency control block and the second frequency control block, the pump control unit being configured to generate a raise-up signal or a pull-down signal according to the first control signal and the second control signal; and a charge pump unit, electrically coupled with the pump control unit, the charge pump unit being configured to generate a control current for raising up the frequency of the output signal according to the raise-up signal or piling down the frequency of the output signal according to the pull-down signal.