Frequency synthesizer and high-speed automatic calibration device therefor
US8008956B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 2010 |
| Grant date | Aug 30, 2011 |
| Priority date | — |
| Expiry date | May 28, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L2207/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer and an automatic calibration device are disclosed. An automatic calibration device for a phase-locked loop based frequency synthesizer includes: a frequency-to-digital converter for converting a frequency of a signal outputted from a voltage controlled oscillator into a first digital value; a frequency difference detector for calculating a difference between the first digital value outputted from the frequency-to-digital converter and a second digital value corresponding to a target frequency; an automatic frequency calibration logic for selecting an optimal control code for a capacitor bank such that an output frequency of the voltage controlled oscillator is closer to the target frequency; and a loop bandwidth calibration logic for tuning a charge pump gain such that a loop bandwidth is kept constant in the optimal control code using the frequency-to-digital converter. Thus, the calibration speed can be increased, and the loop bandwidth can be kept constant within the output frequency range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.