Digital phase error detector for locking to color subcarrier of video signals

A digital phase error detector for locking to a color subcarrier signal in an analog video signal. The digital phase error detector includes a digitizer responsive to a sample clock which generates a first digital data stream from the analog video signal. Filtering circuitry filters the first digita...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: HULVEY, ROBERT W, GUZZINO, KIM S, SHREVE, GREGORY A
Format: Patent
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:A digital phase error detector for locking to a color subcarrier signal in an analog video signal. The digital phase error detector includes a digitizer responsive to a sample clock which generates a first digital data stream from the analog video signal. Filtering circuitry filters the first digital data stream to generate a second data stream by substantially eliminating DC offset of the color subcarrier signal digitized by the digitizer. A mixer mixes the second digital data stream to generate a third digital data stream representing sum and difference frequencies of a product of the color subcarrier signal and a reference clock. An accumulator accumulates this product which represents a phase error between the color subcarrier signal and the reference clock. A voltage controlled oscillator is responsive to this phase error for generating the sample clock.