Patent · US Expired

Phase-Locked Loop

US7054403B2 · kind B2 · utility

8Cited by
6References
22Claims
0Family size

Assignees

Inventors

Key dates

Filing dateMar 21, 2001
Grant dateMay 30, 2006
Priority date
Expiry dateMay 16, 2023

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03L7/104
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A phase lock circuit has a signal path to which a phase comparator, a loop filter and a voltage control oscillator are connected in series, the phase comparator being adapted to compare the phase of an input signal VIN with the phase in the output signal of the voltage control oscillator and to output its result of comparison, the loop filter being adapted to receive the output signal of the phase comparator and to output a DC voltage; the voltage control oscillator being adapted to control the output oscillation frequency depending on the DC output voltage of the loop filter, the phase lock circuit further comprising voltage tracking means for adding, to the voltage of the signal path, a signal causing the average voltage in the output voltage of the phase comparator to coincide with a predetermined reference voltage, whereby the voltage tracking means can enlarge the lock range in the phase lock circuit.

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