US 7,095,992 B2 · Phase locked loop calibration

Abstract

A method for calibrating a phase locked loop (PLL) includes an open loop test and a closed loop test. The open loop test includes providing an optimal control input to a controlled oscillator (CO) of the PLL; determining rate of output oscillation of the CO based on the optimal control input; comparing the rate of the output oscillation with rate of an optimal output oscillation; and when the comparing the rate of the output oscillation with rate of the optimal output oscillation is unfavorable, adjusting an oscillation point of the CO until the comparing is favorable to produce an open-loop adjusted CO oscillation point. The close loop test includes determining a closed-loop input control level of the CO at the open-loop adjusted CO oscillation point; comparing the closed-loop input control level with the optimal control input; and when the comparing the closed-loop input control level with the optimal control input is not favorable, adjusting the open-loop adjusted CO oscillation point until the comparing is favorable.

Claims21

Dependent claims

A method for calibrating a phase locked loop (PLL), the method comprises:

performing an open loop test on the PLL by:
providing an optimal control input to a controlled oscillator (CO) of the PLL;
determining rate of output oscillation of the CO based on the optimal control input;
comparing the rate of the output oscillation with rate of an optimal output oscillation;
when the comparing the rate of the output oscillation with rate of the optimal output oscillation is unfavorable, adjusting an oscillation point of the CO until the comparing the rate of the output oscillation with rate of an optimal output oscillation is favorable to produce an open-loop adjusted CO oscillation point;
and
performing a closed loop test of the PLL by:
determining a closed-loop input control level of the CO at the open-loop adjusted CO oscillation point;
comparing the closed-loop input control level with the optimal control input;
and
when the comparing the closed-loop input control level with the optimal control input is not favorable, adjusting the open-loop adjusted CO oscillation point until the comparing the closed-loop input control level with the optimal control input is favorable.

8 more elements

A phase locked loop (PLL) comprises:

regulation module operably coupled to generate a control signal based on at least one of a phase difference and a frequency difference between a reference oscillation and a feedback oscillation;
controlled oscillator operably coupled to produce an output oscillation based on the control signal;
and
feedback module operably coupled to produce the feedback oscillation based on a divider value and the output oscillation, wherein the regulation module functions to calibrate the PLL by:
performing an open loop test on the PLL by:
providing an optimal control input to the controlled oscillator;
determining rate of output oscillation of the controlled oscillator based on the optimal control input;
comparing the rate of the output oscillation with rate of an optimal output oscillation;
when the comparing the rate of the output oscillation with rate of the optimal output oscillation is unfavorable, adjusting an oscillation point of the controlled oscillator until the comparing the rate of the output oscillation with rate of an optimal output oscillation is favorable to produce an open-loop adjusted controlled oscillator oscillation point;
and
performing a closed loop test of the PLL by:
determining a closed-loop input control level of the controlled oscillator at the open-loop adjusted controlled oscillator oscillation point;
comparing the closed-loop input control level with the optimal control input;
and
when the comparing the closed-loop input control level with the optimal control input is not favorable, adjusting the open-loop adjusted controlled oscillator oscillation point until the comparing the closed-loop input control level with the optimal control input is favorable.

12 more elements

A radio frequency integrated circuit (RFIC) comprises:

a transmitter section operably coupled to convert outbound data into outbound radio frequency (RF) signals based on a transmitter local oscillation;
a receiver section operably coupled to convert inbound RF signals into inbound data based on a receiver local oscillation;
and
a local oscillation generator operably coupled to produce the transmitter local oscillation and the receiver local oscillation, wherein the local oscillation generator includes:
regulation module operably coupled to generate a control signal based on at least one of a phase difference and a frequency difference between a reference oscillation and a feedback oscillation;
controlled oscillator operably coupled to produce an output oscillation based on the control signal, wherein the transmitter local oscillation and the receiver local oscillation are derived from the output oscillation;
and
feedback module operably coupled to produce the feedback oscillation based on a divider value and the output oscillation, wherein the regulation module functions to calibrate the PLL by:
performing an open loop test on the PLL by:
providing an optimal control input to the controlled oscillator;
determining rate of output oscillation of the controlled oscillator based on the optimal control input;
comparing the rate of the output oscillation with rate of an optimal output oscillation;
when the comparing the rate of the output oscillation with rate of the optimal output oscillation is unfavorable, adjusting an oscillation point of the controlled oscillator until the comparing the rate of the output oscillation with rate of an optimal output oscillation is favorable to produce an open-loop adjusted controlled oscillator oscillation point;
and
performing a closed loop test of the PLL by:
determining a closed-loop input control level of the controlled oscillator at the open-loop adjusted controlled oscillator oscillation point;
comparing the closed-loop input control level with the optimal control input;
and
when the comparing the closed-loop input control level with the optimal control input is not favorable, adjusting the open-loop adjusted controlled oscillator oscillation point until the comparing the closed-loop input control level with the optimal control input is favorable.

16 more elements

Dependencies are inferred from the claim text.

Phase locked loop calibration

Life of this patent

Phase locked loop calibration

Life of this patent

Abstract

Claims21