Systems and methods for reducing static phase error
AssigneeLattice Semiconductor Corporation
InventorsLudmil Nikolov, Harald Weller, Michael France, Ji Zhao
Life of this patent
Estimating the term…
Abstract
In accordance with one or more embodiments of the present invention, a system includes a phase-locked loop circuit that receives a reference signal and a feedback signal and provides an output signal. A control circuit also receives the reference signal and the feedback signal and provides a correction current for the phase-locked loop circuit to reduce a phase error of the output signal.
Claims23
A system comprising:
- a phase-locked loop circuit adapted to receive a reference signal and a feedback signal and provide an output signal;
- and
- a control circuit responsive to the reference signal and the feedback signal and adapted to modify a loop filter current of a loop filter within the phase-locked loop circuit to reduce a phase error of the output signal;
- wherein the control circuit is adapted to modify the loop filter current by at least one of providing a current to and receiving a current from at least one of a positive node and a negative node of the loop filter.
(canceled)
An integrated circuit comprising:
- a phase-locked loop adapted to receive a reference signal and a feedback signal and provide a phase-locked loop output signal;
- means responsive to the reference signal and the feedback signal for providing a correction current to the phase-locked loop to reduce a phase error of the phase-locked loop output signal;
- and
- means for generating a clock signal for the providing means, wherein a frequency of the clock signal is less than a frequency of the reference signal.
(canceled)
A method of reducing a phase error of a phase-locked loop output signal from a phase-locked loop circuit, the method comprising:
- receiving by the phase-locked loop circuit a reference signal and a feedback signal;
- providing the phase-locked loop output signal, from the phase-locked loop circuit, based on the reference signal and the feedback signal;
- determining a value of a correction current based on the reference signal and the feedback signal;
- and
- providing the correction current, based on the determining, to the phase-locked loop circuit to reduce a phase error of the phase-locked loop output signal, wherein the providing of the correction current comprises sinking the value of the correction current from a positive or a negative node of a loop filter of the phase-locked loop circuit.
(canceled)
Dependencies are inferred from the claim text.