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RGB to Component Converter

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paul_g_787:

--- Quote from: Benta on October 18, 2021, 03:55:21 pm ---You can place transient protection ot the input if you like, it depends on how harsh your environment is (probably not necessary for video).

Just leave the data lines open, or even better terminate them correctly.

--- End quote ---

I think it would be wise to have some kind of protection. What is the standard practice?

What would be the correct way to terminate the unused USB data lines?

And would I need any kind of filtering between the USB connector shield and GND?

Benta:
A Transzorb/TVS, I'd suggest 5.6 V. A simple Zener could also do it.
Here's a selection:
https://www.vishay.com/diodes/protection-tvs-esd/trans-zorb/

For USB termination: hey, you need to do a bit of research yourself.

Terry Bites:
A linear supply is a good idea in AV, not that switchers are no good, its just a potential problem you can eliminate off the bat.
TI's THS7315 is great vfm compared to the LM6172, about twice the price of a single genuine 072. Rohm used to make a dedicated IC  BA7230LS. Like so many analog video ICs its gone to meet its maker. I believe that there are still some MC1377s still in the aether. Comodore fan boys can help.

The TL072 would be problematic  The frequncy/ phase response of the opamp  is the obvious culprit. I'm not too sure its happy driving a low imopedance load. the video bandwith at SD it 12MHz. At unity gain this opamp is out of its depth.

I spent a small fortune on racks of analog matrix switches just before HDMI appeared. It made a grown man cry. Still, not my own cash!

Terry Bites:
Curiosity got the better of me see page 14 of https://www.analog.com/media/en/technical-documentation/data-sheets/65501fa.pdf
Life made easy and it runs happily on +-3V3. You can make it single supply but you'll be bogged down in coupling caps and the evils of sag.
The LM1981 is your dream sync detector, it works with all analog video formats including 1080p/s. A CD4541 timer can be contunually reset by H or V sync when sync lost, it starts counting down to turn-off.

Benta:

--- Quote from: Terry Bites on October 19, 2021, 01:43:40 pm ---Curiosity got the better of me see page 14 of https://www.analog.com/media/en/technical-documentation/data-sheets/65501fa.pdf
Life made easy and it runs happily on +-3V3. You can make it single supply but you'll be bogged down in coupling caps and the evils of sag.
The LM1981 is your dream sync detector, it works with all analog video formats including 1080p/s. A CD4541 timer can be contunually reset by H or V sync when sync lost, it starts counting down to turn-off.

--- End quote ---

The pricing of LT6550 is not exactly a bargain compared to LM6172.
And the LMH1981 is not exactly cheap either ($6 at 1k units).

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