MichaelZ tipped us to a 64-channel, current-input analog-to-digital converter

The DDC264 is a 20-bit, 64-channel, current-input analog-to-digital (A/D) converter. It combines both current-to-voltage and A/D conversion so that 64 separate low-level current output devices, such as photodiodes, can be directly connected to its inputs and digitized.

For each of the 64 inputs, the DDC264 uses the proven dual switched integrator front-end. This configuration allows for continuous current integration: while one integrator is being digitized by the onboard A/D converter, the other is integrating the input current. This architecture provides both a very stable offset and a loss-less collection of the input current. Adjustable integration times range from 160ms to 1s, allowing currents from fAs to mAs to be continuously measured with outstanding precision.

Thanks McZ!

Read more: http://dangerousprototypes.com/2011/02/05/64-channel-current-input-analog-to-digital-converter/