PLL oscillation circuit
US7656208B2 · kind B2 · utility
3Cited by
6References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2007 |
| Grant date | Feb 2, 2010 |
| Priority date | — |
| Expiry date | Jul 12, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/085
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digitally controlled PLL oscillation circuit has a VCO, a frequency divider, a reference oscillation circuit, an A/D converter, a phase comparator, a digital filter, a D/A converter, and an analog filter. A reference signal supplied from the reference oscillation circuit is output through a narrow-band crystal filter (MCF) to the A/D converter to cancel noise, jitter and a spurious wave included in the reference signal, making it possible to prevent the phase noise characteristic and spurious characteristic of a VCO output from being degraded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.