High-speed, accurate trimming for electronically trimmed VCO
US7295078B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2003 |
| Grant date | Nov 13, 2007 |
| Priority date | — |
| Expiry date | Sep 22, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/193
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuning circuit uses a VCO with a trimming capacitor bank. The trimming capacitor bank is calibrated by logic to accommodate a desired frequency, fwanted. A search renders an initial control word that is accurate within one LSB. In a first embodiment, comparisons between the desired frequency and the upper and lower frequency bounds of the VCO with the trimming capacitor bank configured by the initial control word. The control word may be increased or decreased based on the comparisons. In a second embodiment, differences between the desired frequency and the actual frequency of the VCO, with the trimming capacitor bank configured by the initial control word, are compared to a threshold. The control word may be increased or decreased based on the comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.