Phase lock detector for digital frequency synthesizer
US3988696A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Nov 28, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S331/02
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase lock detector for a digital frequency synthesizer. The frequency synthesizer includes a programmable digital frequency divider for the output signal, a reference frequency Fr oscillator and a phase lock loop which controls the frequency of the synthesizer output by comparing the phase of the frequency divider signal with the phase of the reference signal. The frequency Fr of the synthesizer is determined by programming N in the relationship ##EQU1## The phase lock detector includes logic means providing a "window" which is "open" for a count which is symmetrically less than and more than the factor M. The detector does not signal "out-of-lock" condition as long as output from the programmable divider occurs during the time the detector window is open.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.