Fractional-N phase-locked loop with reduced jitter
In an example, operating a PLL circuit includes generating an error signal in response to comparison of a reference clock signal having a reference frequency and a feedback clock signal having a feedback frequency, generating a plurality of clock signals having an output frequency based on the error...
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Zusammenfassung: | In an example, operating a PLL circuit includes generating an error signal in response to comparison of a reference clock signal having a reference frequency and a feedback clock signal having a feedback frequency, generating a plurality of clock signals having an output frequency based on the error signal, and generating the feedback clock signal from the plurality of clock signals based on a first divider value and a control value derived from a second divider value. Operating the PLL circuit further includes multiplying each of a first integer value and a first fractional value by a power of two to generate a second integer value and a second fractional value, respectively, generating the second divider value using a sigma-delta modulator (SDM) based on the second integer value and the second fractional value, and dividing the second divider value by the power of two to generate the first divider value. |
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