AD724 with subcarrier frequency lock

Hi,

I would like to generate CVBS with the AD724 or AD725, with the colour subcarrier locked to an existing video signal, for an OSD application. Is this possible?

I'm thinking to use an MC44144 to lock to the colourburst, then buffer the 4FSC output using a comparator to convert the AC sinewave to a TTL square wave. Will this work, or alternatively can anyone suggest a better method?

Thanks,

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  • 0
    •  Analog Employees 
    on Nov 8, 2017 7:32 PM over 3 years ago

    Hi Peter,

    I'm not familiar with some of the components you have used and we do not support non-ADI products in the EngineerZone, but judging with the schematic you provided and I've also scanned the datasheets of your components, this should work. Just make sure your comparator is fast enough to convert your subcarrier frequency correctly.

    Also, the AD724 only accepts interlaced RGB videos.

    May I know what component is U5 and the micro-controller you're using?

    Regards,
    Goz

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  • 0
    •  Analog Employees 
    on Nov 8, 2017 7:32 PM over 3 years ago

    Hi Peter,

    I'm not familiar with some of the components you have used and we do not support non-ADI products in the EngineerZone, but judging with the schematic you provided and I've also scanned the datasheets of your components, this should work. Just make sure your comparator is fast enough to convert your subcarrier frequency correctly.

    Also, the AD724 only accepts interlaced RGB videos.

    May I know what component is U5 and the micro-controller you're using?

    Regards,
    Goz

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