Patent · US Expired

Delay matching circuit

US5376848A · kind A · utility

23Cited by
5References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 5, 1993
Grant dateDec 27, 1994
Priority date
Expiry dateApr 5, 2013

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K2005/00117
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A delay matching circuit has a first node (48), a second node (50), a first loading circuit (54, 56), a second loading circuit (58, 60), a third loading circuit (64) and a buffer circuit (62). The first loading circuit couples a first logic state to the first node responsive to a first state of a control signal. The second loading circuit couples a second logic state to the first node responsive to a second state of the control signal. The buffer circuit electrically couples the first and second nodes. The first loading circuit, second loading circuit and buffer circuit are characterized by a first, a second and a third predetermined electrical impedance, respectively. The third loading circuit is coupled to the second node and is characterized by a fourth predetermined electrical impedance. The disclosed delay matching circuit propagates a clock signal input with a delay equal to the Clock-to-Q delay associated with a flip-flop constructed with similar circuit elements. The disclosed delay matching circuit is useful in circuits, such as phase locked loops, where the simultaneous propagation of two signals is critical.

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