VLSI multi-channel track-and-hold potentiostat

Simultaneous mapping of neural activity facilitates understanding neurological phenomena and their underlying mechanisms. We present a track-and-hold potentiostat performing simultaneous acquisition of 16 independent channels of current ranging five orders of magnitude in dynamic range over four scales down to hundreds of picoamperes. Sampling rate ranges from DC to 200KHz. The system features programmable current gain control, configurable anti-aliasing log-domain filter, triggered current integration and provides differential output ready for asynchronous external analog-to-digital conversion over a compressed dynamic range. We present system description, circuit implementation and experimental results of real-time neurotransmitter concentration measurements from the 16-channel prototype fabricated in a 1.2 mum CMOS process.