Title: Automatic regulating method and circuit for phase locking loop frequency synthesizer switch capacitor
Application Number: 200610027203 Application Date: 2006.06.01
Publication Number: 1859008 Publication Date: 2006.11.08
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03L7/099,H03L7/08
Applicant(s) Name: Zhang Haiqing Address: 201204
Inventor(s) Name:
Attorney & Agent: lu fei sheng zhifan
Abstract:
     This invention relates to an automatic adjusting method and a realization circuit for the switch of a phase-locking loop frequency synthesizer switch capacitance, which changes the LC resonance structure of the voltage-controlled oscillator in a phase-locking loop frequency synthesizer to a structure of a variable capacitor and switch capacitor array and adds a switch capacitance control module for testing the voltage variance of the voltage-controlled oscillator to control the load of the switch capacitor and regulate the central frequency of the oscillator to get even better performance of synthesizers, said control module is composed of two hysteresis comparators and a FSM for regulating the switch, the input of the comparator is control voltage having high and low threshold voltages, the FSM controls the switch of the switch capacitor array.
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