The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1992
Filed:
Mar. 14, 1990
Christopher P Summers, London, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
A digital phase detector circuit has an up/down counter for counting clock pulses (CPS) to determine the number of clock pulses that occur in the time interval between opposite edges of a first signal (VSC) and one edge of a reference signal (PL) synchronized with the clock pulses (CPS). A latch provides a first digital output signal (DES) which represents the number. The phase detector also has an analogue phase detector circuit having a flip-flop for producing a second signal (VCS') which corresponds to the first signal (VCS) and is synchronized with the clock pulses (CPS). Logic gates and determine the time intervals between corresponding edges of the first and second signals (VCS,VCS'), and a circuit element determines a phase error voltage (VS) from these time intervals. The voltage (VS) is digitized to provide a second digital output signal (AES). The first and second digital output signals (DES,AES) are combined to produce a resultant digital output signal (DPE) which represents an overall indication of phase difference.