The above is very valid for good analog and digital design and should be followed to a "matching extent" in all cases. However when using only an 8 bit a/d there is no need to overdesign the interface. Please note I post "no need to overdesign" NOT "ignore all rules". I will even suggest that an idea might be to use a chip such as the LPC935 that has the a/d built in.

Prahad has never indicated what precision he is aiming for, with an 8 bit A/D it can not be extreme. If he is trying to suck that last bit of precision out of the A/D it is a much better idea to use a 10/12 bitter and average the readings.

Erik