Hi Frank,

On Fri, Mar 27, 2026 at 02:41:21PM -0400, Frank Li wrote:

Accroding to signal name, it is MUX chip select signal. Of couse it may
connect to a buffer's EN pin. I have not checked your schematic.

If it connect to MUX chip or some select signal, it should use above method,
even though it is permanently asserted when access PCA6408.

If it connect to EN pin of buffer, regualtor should be good.

Yes, it is exactly the second case!
It's just an EN pin, that enables a buffer to route RGB signals used on
the DART-MX91 som only.
That's why I think regulator is the right way for this case.

Best Regards,
Stefano