High frequency spread spectrum clock generation
US7561652B2 · kind B2 · utility
3Cited by
34References
19Claims
0Family size
Inventors
Key dates
| Filing date | Apr 22, 2003 |
| Grant date | Jul 14, 2009 |
| Priority date | — |
| Expiry date | Jun 2, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
For EMI reduction the current modulation profile is preferably used for frequencies over 1 GHz while the frequency deviation is increased at least to ±2.5 MHz and the modulation frequency is increased to at least 150 kHz, preferably about 260 kHz. In an alternative embodiment, the modification frequency is 1 MHz or greater so that a segmented spectrum is achieved. For clocks having basic frequency below 1 GHz, but having strong harmonics higher than 1 GHz, modulation of the foregoing is combined with the slower modulation currently used. EMI reduction is realized both at the lower and the higher harmonics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.