Phase-lock loop
AssigneeInfineon Technologies AG
InventorsChin Yeong Koh, Kar Ming Yong
Life of this patent
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Abstract
In one implementation an output signal of an oscillator is varied to be within a desired frequency band with respect to a reference signal, the output signal having a plurality of phases. The implementation may include comparing the output signal with the reference signal, counting falling edges about each phase of the number of phases in a predetermined time period and summing to define a count output; comparing the count output with a product of the number of phases of the output signal and the factor to define a comparison, generating a control signal based upon the comparison, and inputting the control signal to the oscillator to alter the output signal thereof.
Claims16
A phase-lock loop comprising:
- an input configured to receive a reference signal;
- an oscillator configured to:
- receive a control signal, and
- generate an output signal, wherein the output signal of the oscillator comprises a plurality of phases;
- a frequency divider configured to:
- receive the output signal of the oscillator, and
- divide down a frequency of the output signal of the oscillator by a factor, defining
- a divided down signal;
- a frequency detector configured to:
- receive the output signal of the oscillator,
- receive the reference signal, and
- generate a comparison signal based on a comparison of frequencies of the reference signal and the output signal of the oscillator;
- a phase detector configured to:
- receive the divided down signal,
- receive the reference signal, and
- generate an output signal based on a comparison of the phases of the divided down signal and the reference signal;
- and
- a loop filter configured to:
- receive the comparison signal,
- receive the output signal of the phase detector, and
- generate the control signal based upon the comparison signal and the output signal of the phase detector, with the control signal altering the output signal of the phase detector.
A device comprising:
- an oscillator to receive a control signal and having an output to generate an output signal that is dependent on the control signal, wherein the output signal of the oscillator comprises a plurality of phases;
- a frequency detector having a first input coupled to the output of the oscillator and a second input to receive a reference signal, wherein the frequency detector is configured to:
- compare the output signal of the oscillator with the reference signal, and
- generate a frequency difference signal at an output of the frequency detector, wherein generating the frequency difference signal comprises at least counting edges associated with one or more signals in a predetermined time period and defining a count output based on the count of the edges;
- and
- a loop filter configured to:
- receive the frequency difference signal, and
- generate the control signal based at least in part on the frequency difference signal.
A method comprising:
- comparing an output signal with a reference signal, wherein the output signal comprises a plurality of phases, wherein comparing comprises:
- counting falling edges associated with each phase of the output signal during a period of the reference signal;
- summing the counts for each phase of the plurality of phases to define a count output;
- comparing the count output with a product and a factor to define a comparison;
- and
- generating a control signal based upon comparing the count output with the product and the factor.
A phase-lock loop comprising:
- an oscillator configured to generate an output signal having a phase, wherein the output signal of the oscillator comprises a plurality of phases;
- a frequency detector configured to receive the output signal of the oscillator, wherein the frequency detector is configured to:
- detect at least one falling edge of the output signal of the oscillator;
- increase a count for each falling edge detected;
- detect a falling edge of a reference signal;
- define a count summation related to a number of phases associated with the output signal of the oscillator;
- and
- compare the count summation with a product of the number of phases of the output signal of the oscillator and a factor, defining a comparison signal;
- and
- a loop filter configured to:
- receive the comparison signal, and
- generate a control signal based upon the comparison signal, with the control signal altering the output signal of the oscillator.
Dependencies are inferred from the claim text.