Spread spectrum phase-locked loop clock generator with VCO driven by a symmetrical voltage ramp signal
US5659587A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 23, 1994 |
| Grant date | Aug 19, 1997 |
| Priority date | — |
| Expiry date | Nov 23, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2201/0208
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase-locked loop circuit comprises a VCO and a ramp generator. The ramp generator has an output connected to a control terminal of the VCO. A center frequency control loop is connected between a signal output terminal of the VCO and a first ramp control input of the ramp generator and a spread spectrum control loop is connected between the signal output terminal of the VCO and a second ramp control input of the ramp generator. The signals applied to the ramp control inputs of the ramp generator by the two control loops control respective characteristics of a periodic voltage ramp signal that is generated by the ramp generator at its signal output terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.