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I am currently trying to create a circuit which will convert a 75 ohm Green RGB line with sync (sync on Green) to just Green. I will attach a very basic diagram. My question is will the latency cause me any problems. As you can see one Gs line goes straight to the subtracter and one line has to go through a sync stripper and op amp. Will the two lines be in sync so the "sync" line can be subtracted from the Gs line to create an G signal?


Basic circuit

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    \$\begingroup\$ This app note might be useful. You could probably eliminate the DC restoration part of the circuit in that app note, and just stick with the sync stripper part. \$\endgroup\$ Sep 1 '16 at 2:42
  • \$\begingroup\$ Thanks @TomCarpenter This IC will definitely simplify this circuit a huge amount. I might still have a latency problem if I pass one G line through the EL8012 and one through the LM1881. I will use the separate lines to recreate the image \$\endgroup\$ Sep 1 '16 at 3:07
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I have found a better way which let's me strip the sync from an RGB signal using two op-amps. One as a comparator which feeds into the other one's low rail to limit it's output. Look for OPA698. Better way to do it. Also to get the sync, split the signal and send it to a sync stripper like a LM1881 to extract sync information.

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  • \$\begingroup\$ Thanks for posting your solution! I'm looking to do something very similar: taking a NeXT sync-on-green video signal to normal vga (separating into H and V sync, then stripping sync from green). I found the sync stripper circuit example in the OPA698 datasheet fig 19, but I'd love to see your final circuit. In particular how you are generating the -.2V input to the second OPA698? If Vin is the Green signal, are you using a converter to get down to -2 volts? The lm1881 to get hv sync seem straightforward... \$\endgroup\$
    – bhoward
    May 2 '17 at 20:24

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