My reasonig was that I should build metal casing around the ADC by making a ground plane of the top layer and pass the signals through vias to bottom plane where will be the digital part. Over the chip i thought to place thin copper casing, and solder it on, making it RF-proof (no input noise).
Of course, both signal wires shuuld be in schielded cables, similiar to those used in osciloscope probes..
As a reference, I could use a REF02, or you can think of a better one?
to Oznog;
Thanx .From all above, your reply was the most useful. Could you refer to some tech info on that RCR type filtering of input?
So far, I was sugested to allways use a RC filter on the input of a ADC, so I used 100k, 1µ for the filtering.
to others:
I know that it would be almouset impossible to acheve all the bits, but, how it's don in audio recording equipment??
And one other thing, whattype of protection do you suggest for the input? I Used diodes after serial resistor, drawing the current to VCC and VDD, but I think that their Ir would in this case do a lot of damage on accuracy