Reducing phase locked loop phase lock time
There is provided a method for reducing lock time in a phase locked loop. The method includes detecting a saturation condition on a path within the phase locked loop. The method further includes temporarily applying saturation compensation along the path when the saturation condition is detected.
1. A method for reducing lock time in a phase locked loop, the method comprising:
detecting a saturation condition on a path within the phase locked loop; and
temporarily applying saturation compensation along the path when the saturation condition is detected.
2. The method of claim 1 , wherein the phase locked loop has a proportional path and an integral path, and wherein the saturation condition is detected and compensated for on the proportional path.
3. The method of claim 2 , wherein the proportional path includes a coarse band controller for controlling an oscillator coarse band, and wherein the saturation compensation adjusts the oscillator coarse band to compensate for the saturation condition.
4. The method of claim 3 , wherein the oscillator coarse band is adjusted using memory-less switching.
5. The method of claim 3 , wherein the oscillator coarse band is adjusted to a particular compensating value from an original value, the original value corresponding to a non-saturation condition of the path, and wherein the oscillator coarse band is returned to the original value from the particular compensating value when a voltage of the proportional path returns to a non-saturated range.
6. The method of claim 1 , wherein the saturation compensation changes the relative gain on the path.
7. The method of claim 6 , wherein the path includes a coarse band controller for controlling an oscillator coarse band, and the relative gain on the path is changed by modulating the oscillator coarse band between an incremented state and an original state to provide at least one of a reduced average frequency change and a reduced average phase change over a given time period as compared to using only the incremented state, the original state corresponding to a non-saturation condition of the path.
8. The method of claim 1 , wherein the phase locked loop is an analog phase locked loop.
9. The method of claim 1 , wherein the phase locked loop is a digital phase locked loop.
10. The method of claim 1 , wherein detecting a saturation condition on a path within the phase locked loop comprises using one or more comparators to detect the saturation condition on the path.
11. An apparatus for reducing lock time in a phase locked loop, the apparatus comprising:
a saturation compensator for detecting a saturation condition on a path within the phase locked loop, and temporarily applying saturation compensation along the path when the saturation condition is detected.
12. The apparatus of claim 11 , wherein the phase locked loop has a proportional path and an integral path, and wherein the saturation condition is detected and compensated for on the proportional path.
13. The apparatus of claim 12 , wherein the proportional path includes a coarse band controller for controlling an oscillator coarse band, and wherein the saturation compensation adjusts the oscillator coarse band to compensate for the saturation condition.
14. The apparatus of claim 13 , wherein the oscillator coarse band is adjusted using memory-less switching.
15. The apparatus of claim 13 , wherein the oscillator coarse band is adjusted to a particular compensating value from an original value, the original value corresponding to a non-saturation condition of the path, and wherein the oscillator coarse band is returned to the original value from the particular compensating value when a voltage of the proportional path returns to a non-saturated range.
16. The apparatus of claim 11 , wherein the saturation compensation changes the relative gain on the path.
17. The apparatus of claim 16 , wherein the path includes a coarse band controller for controlling an oscillator coarse band, and the relative gain on the path is changed by modulating the oscillator coarse band between an incremented state and an original state to provide at least one of a reduced average frequency change and a reduced average phase change over a given time period as compared to using only the incremented state, the original state corresponding to a non-saturation condition of the path.
18. The apparatus of claim 11 , wherein the phase locked loop is an analog phase locked loop.
19. The apparatus of claim 11 , wherein the phase locked loop is a digital phase locked loop.
20. The apparatus of claim 11 , wherein the saturation compensator comprises one or more comparators for detecting the saturation condition on the path.
21. A non-transitory computer readable storage medium comprising a computer readable program, wherein the computer readable program when executed on a computer causes the computer to perform the following:
detect a saturation condition on a path within the phase locked loop; and
temporarily apply saturation compensation along the path when the saturation condition is detected.
22. The computer readable storage medium of claim 21 , wherein the path includes a coarse band controller for controlling an oscillator coarse band, and wherein the oscillator coarse band is adjusted to compensate for the saturation condition.
23. The computer readable storage medium of claim 22 , wherein the oscillator coarse band is adjusted using memory-less switching.
24. The computer readable storage medium of claim 22 , wherein the oscillator coarse band is adjusted to a particular compensating value from an original value, the original value corresponding to a non-saturation condition of the path, and wherein the oscillator coarse band is returned to the original value from the particular compensating value when a voltage of the proportional path returns to a non-saturated range.
25. A method for reducing lock time in a phase locked loop having an integral control path and a proportional control path, the method comprising:
detecting a saturation condition on the proportional control path; and
temporarily applying saturation compensation along the proportional control path when the saturation condition is detected by adjusting a relative gain on the proportional control path,
wherein the proportional control path includes a coarse band controller for controlling an oscillator coarse band, and the relative gain on the path is adjusted by modulating the oscillator coarse band between an incremented state and an original state to provide at least one of a reduced average frequency change and a reduced average phase change over a given time period as compared to using only the incremented state, the original state corresponding to a non-saturation condition of the proportional control path.