Higher Resolution ADC's?

Hello All:

Has any one seen any shields, or Arduino variants, that offer higher than 10-bit resolution on the analog inputs?

12-bit would work for my application, but 16-would be fantastic (may be even over-the-top).

Or, perhaps, any tricks with successive approximation to improve resolution?

-Gnerffed

Like this? :)

I've used a pair of MCP3208s on a protoshield, with two such protoshields on an arduino (total of 32 inputs). They're 8 channel 12 bit SPI interfaced ADCs from Microchip, available in DIP or SMT.

They're not super fast; I think they max out around 1 or 2MHz on the SPI bus.

There is working code for a single unit on the playground, and I've modified that to allow for multiple units on the same arduino.

I'm also prototyping a shield for a TLV2548 8 channel 12 bit from TI. They're SMT only, but their sample rate is twice that of the MCP3208, plus their SPI speed is much faster.

-j