Front end circuit

A band-pass filter (175) separates an audio intermediate frequency signal (SIFS) from an input television intermediate frequency signal (SIF), and an A/D converter circuit (215) converts the signal (SIFS) into a digital signal (DIFS). A digital signal processor (225) performs audio detection on the...

Ausführliche Beschreibung

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Bibliographische Detailangaben
Hauptverfasser: YANAGI SHIGETO, CHONO TOSHIYUKI, SANO HIROMICHI
Format: Patent
Sprache:eng
Schlagworte:
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Beschreibung
Zusammenfassung:A band-pass filter (175) separates an audio intermediate frequency signal (SIFS) from an input television intermediate frequency signal (SIF), and an A/D converter circuit (215) converts the signal (SIFS) into a digital signal (DIFS). A digital signal processor (225) performs audio detection on the signal (DIFS) and forms an AGC signal (DAGCS) based on the signal (DIFS). A variable gain amplifier (185) performs AGC on the audio intermediate frequency signal. A band-pass filter (175) separates and takes out a video intermediate frequency signal (SIFP) from the input television intermediate frequency signal (SIF), and an A/D converter circuit (21P) converts the signal (SIFP) into a digital signal (DIFP). A digital signal processor (22P) performs video detection on the signal (DIFP). An AGC signal (DAGC) is formed based on the signals (DIFP) and AGC is performed on the input television intermediate frequency signal (SIF) by using the AGC signal (DAGC).