Patent · US Expired

Delay locked loop circuit

US5994934A · kind A · utility

92Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 8, 1998
Grant dateNov 30, 1999
Priority date
Expiry dateJul 8, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03L7/095
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

Provided is a DLL circuit that can execute a precise delay synchronization operation without increasing the variable delay time range of a delay line. The DLL circuit comprises a phase comparator (3), a charge pump (6), an LPF (8) and a delay line (9), and operates to match phases of an input signal (CLKIN) and a feedback signal (FBCLK). The phase comparator (3) always outputs a phase comparison result that causes a delay time of the delay line (9) to increase, at the time of initial operation after a reset operation. The LPF (8) outputs a delay adjusting signal (S8) indicating that a delay time due to the delay line (9) becomes the minimum, in executing a reset.

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