Phase-locked loop circuit

摘要

A phase-locked loop circuit, a phase converter module thereof and a phase-locked controlling method are disclosed herein. The phase converter module is suitable for a phase-locked loop circuit including a digitally-controlled oscillator (DCO) for generating an oscillator output signal and a divider for converting the oscillator output signal into N-phased oscillator output signals. The phase converter module includes a period extender, a phase finder and a time-to-digital converter. The period extender is configured for extending the N-phased oscillator output signals into M*N-phased oscillator output signals corresponding to M oscillation period of the digitally-controlled oscillator. The phase finder is configured for sampling the oscillator output signal with the M*N-phased oscillator output signals to calculate an estimated value of the fractional phase part. The time-to-digital converter is configured to calculate a precise value of the fractional phase part within one sub-period.

主权项

1. A circuit, comprising:
a digitally-controlled oscillator (DCO) configured for generating an oscillator output signal; a controller configured for setting an oscillation frequency of the oscillator output signal in accordance with a fractional phase part; a divider configured for converting the oscillator output signal into N-phased oscillator output signals corresponding to one oscillation period of the digitally-controlled oscillator; and a phase converter module, comprising:
a period extender, configured for extending the N-phased oscillator output signals into M*N-phased oscillator output signals corresponding to M oscillation period of the digitally-controlled oscillator;a phase finder comprising M*N stages of logic circuits connected in parallel, each stage of the logic circuits configured for sampling the oscillator output signal with one of the M*N-phased oscillator output signals for calculating an estimated value of the fractional phase part; anda time-to-digital converter configured for sampling one of the N-phased oscillator output signals with a reference-frequency signal to calculate a precise value of the fractional phase part.