Help with RGB to S-Video using NTE879

[rdavis]

I'm using the NTE879 (link to pdf) to make a RGB converter so I can play arcade boards on my television set. I've seen other schematics using similar ICs (AD724, AD722), but there's a couple of things that throw me off about this particular IC. The NTE879 has a "Ramp Generator Input" (pin 1). What kind of voltage ramp is it looking for?

Also, there are pins for "Decoupling" (7,11,12,19). Does the IC need a capacitor between each of these pins and ground?

**broken link removed**​

 

[audioguru]

I think the NTE brand gets ICs from normal manufacurers and has their own part number printed on them. They are expensive replacements for the less expensive real original ICs that have complete datasheets with circuit examples. Get and use the real thing and follow its datasheet examples.

 

[rdavis]

The reason I'm using the NTE879 is because it's the only RGB to S-Video converter that I've been able to find in DIP form. Most others are only available in SOIC or TSOP.

 

[audioguru]

Do a reverse lookup on NTE's site for the original IC's part number. Its manufacturer still might have its datasheet.

 

[rdavis]

Yeah, I tried that right after you said that NTE buys out other chip designs. The IC that the NTE879 replaces is the ECG879. Unfortuantely, I can't find anything on this IC or the company that use to make it. Tried alldatasheet.com and google. Nada.

 

[rdavis]

I emailed NTE for any extra information they had on this IC (block diagram, sample circuits, etc). If I don't get a reply, I'm going to take your advice, audioguru, and switch to a different IC (the AD724 or AD 725). I found a SOIC to DIP PCB for about $5.