Patent · US Expired

Circuit for limiting maximum frequency output of a voltage controlled oscillator

US5208555A · kind A · utility

13Cited by
1References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 23, 1991
Grant dateMay 4, 1993
Priority date
Expiry dateSep 23, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03L7/18
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A circuit is which, when used in a voltage controlled oscillator (VCO) circuit, detects a frequency on the output of the VCO and, if this output frequency is above a certain value, the circuit forces the output frequency of the VCO to decrease until it is below the certain value. This acts to keep the output frequency of the VCO below a selected frequency which can be accurately processed by the feedback circuits driven by the VCO. Once the output frequency of the VCO is below the certain value, the circuit stops forcing the output frequency to decrease, and the circuit becomes transparent. At this point, the conventional feedback circuitry driving the VCO takes over the adjustment of the VCO output frequency.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.