Calibration arrangement for frequency synthesizers
US9197403B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2012 |
| Grant date | Nov 24, 2015 |
| Priority date | — |
| Expiry date | Jul 20, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/197
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electronic device has a calibration arrangement for controlling a frequency characteristic of a PLL circuit having a phase comparator having an output for generating a phase difference signal, a voltage controlled oscillator and a divider. The divisor of the divider is programmable, and the oscillator is also directly modulated by an oscillator modulation signal. A modulation unit has a modulation input for receiving a modulation signal and generates the oscillator modulation signal and the divisor such that modulation generates a predefined change of the output frequency and a change of the divisor proportional to said predefined change. The calibration arrangement receives the phase difference signal, and has a ripple detector for providing a detector output signal by detecting a ripple on the phase difference signal correlated to edges in the modulation signal. A calibration control unit adjusts the oscillator modulation signal based on the detector output signal such that the ripple is reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.