It is work performed by experts to make ANY kind of a data acquisition system that performs much better than 12 bits. With LOTS and LOTS of hard work, much money spent on extra hardware and sophisticated software you can get to 14 and 15 bits. The arguments and analysis put forth by Erik and Kai are entirely correct. The thing that is concerning to me and I am sure also a concern to others that have long background history and know that above 14 bits is magic, is the fact that inexperienced engineers and even some that should know better think that just because they find an A/D converter that proports to go to 16 bits, 20 bits or even 24 bits in a ready made package that they are good to go. And god forbid they go for the packaged solution with such 24-bit converter on the same package as a high speed microcontroller. These packaged solutions offered by the manufacturers are leading to some pretty crappy products being designed by people that don't even know what they are doing then yet even know how to begin, know what questions to ask and what analysys to perform.

I can tell you I have built some 12-bit designs with external standalone A/D converters and they were a son-of-a-gun to get designed to provide full 12 bit accuracy.

If any of you work for a company that is having you design a product that they think should be more than 12 bits of A/D converter accuracy OR resoultion and you fall into the category of either having never done it before or you don't really know what you are doing. or you think that the converter should be onboard with the microcontroller then I suggest that you go tell your bosses that they should seek out the services of a reputable analog designer that has experience. Particularly experience that extends through the analysis phase, the design / modeling phase, the PC board artwork design phase, AND possibly most important having experience taking the product through the initial production ramp-up phase.

I have seen too many instances of garbage analog products built by people that should have taken that time for their vacations instead !!

Michael Karas