AD723,AD725,AD725 RGB inputs

I read in all of these datasheets that the AD723,AD725, and AD725 all require interlaced inputs. If I want to feed a  pc's vga output into one of these IC's, would these still convert the RGB to composite? Are there other solutions from Analog Devices that are RGB-to-NTSC Encoders that do not require an interlaced input? The AD723,AD725, and AD725 all looked like good solutions because they can be hardware configured and do not require some configuration scripts over I2C.

Any help on this would be great.

Thank you,

Scott

  • Hi Dave,

    My goal is to have this go onto a PCIE bus. I am currently using another part that has NTSC input and PCIE output and I was going to try and convert the XGA to NTSC so I could add it as another input. My end goal is to get the XGA to a PCIE bus but I did not find any IC combinations/solutions that would be able to make that conversion.

    Does Analog Devices have any time of chipset solution that can do this kind of conversion without losing resolution?

    Thanks,

    Scott

  • 0
    •  Analog Employees 
    on Jun 27, 2011 10:41 PM

    Hi Scott,

    Going from non-NTSC RGB to encoded/modulated NTSC requires scaling/interlacing.  If the format is correct, it's just a matter of color space conversion and modulation which is what those parts all do.

    If the format isn't already correct, it's a much more complicated problem.  I'm assuming you are trying to encode 640x480 as NTSC?

    Dave

  • 0
    •  Analog Employees 
    on Jun 27, 2011 11:24 PM

    Hi Scott,

    Yah.. XGA to NTSC definitely would require scaling.  ADV7181C would certainly digitize XGA but it wouldn't encode it as NTSC in any case.  Your goal is that the output should go to a standard definition TV?

    Dave

  • 0
    •  Analog Employees 
    on Jun 27, 2011 11:37 PM

    Hi Scott,

    Ok.. the PCIE to NTSC was the part I was missing-- it's specifc to encoded analog NTSC or is it digital?  That seems like a strange part.  If the XGA is just digital data, wouldn't any arbitrary PCIE bridge part do the trick?  I imagine some buffering is all you'd need.

    We don't have anything that we can discuss on the forum but a scaler part for what you want doesn't seem like the right solution anyway.

    Dave