[sdiy] A/D converter with good accuracy for a reasonable price?

[Eric Brombaugh]

On May 6, 2011, at 5:02 AM, Karl Ekdahl wrote:

> All; thank you so much for your input!
> 
> Here's a thought tho; i already have a good D/A in my system, and i used that in conjunction with a S&H to make a SAR A/D - it seemed to me like it didn't work at first, hence why i asked about the "real" A/D alternatives. However, now it does indeed seem to work quite well. 
> 
> But to avoid future troubles i wonder if there's any hidden dark sides to do it this way? I realize that i'm loosing processing power but that doesn't bother me.

There shouldn't be any huge issues with a SAR ADC. A lot of fairly high-end devices use this approach. You'll be limited by the accuracy of all the components, settling times, acquisition windows, aperture jitter, etc, so unless you do extensive testing you won't know for certain what the final performance will be as you would if you bought an integrated solution, but that's a problem you can solve with time and thought.

Eric