Error amplifier for multiple frequency oscillator control
US5168246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1991 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | Oct 24, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/126
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multiple frequency scan oscillator control system includes a phase locked loop operative upon a scan oscillator to provide phase and frequency synchronization thereof to a periodic reference signal. A static phase error correction is operative to provide adjustment of the free-running or static frequency of the scan oscillator. An error amplifier includes a pair of intercoupled differential amplifier configurations one having a constant current source and the other having a frequency dependent current source which responds to a frequency dependent bias current to alter amplifier gain. A threshold detection circuit includes a differential amplifier pair coupled to a pair of switching circuits for establishing a threshold action in response to system error voltage to indicate large magnitude error voltages and signal the need for free-running frequency adjustment of the oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.