Alan E Mathieu

US Patent:

51929155, Mar 9, 1993

Filed:

Jul 27, 1992

Appl. No.:

7/920180

Inventors:

Alan E. Mathieu - Portland OR
Edward D. Wardzala - Portland OR
Michael S. Overton - Aloha OR

Assignee:

Tektronix, Inc. - Wilsonville OR

International Classification:

H03K 906
H03K 513

US Classification:

328133

Abstract:

An edge integrating phase detector for a phase locked loop passes a portion of a sync edge of an input video signal as a sampled signal to an integrator in response to a gate pulse nominally centered on a timing reference point of the sync edge. The sampled signal has a positive and negative portion. The integrator produces from the sampled signal a control signal for a VCO that is proportional to the unbalance between the positive and negative portions. The gate pulse is generated from the output of the VCO as a function of the nominal period of the input video signal.