A current mode multi-channel Wilkinson ADC

A current mode multi-channel ADC has been designed in a 0.5-mum bulk CMOS process. The ADC is capable of supporting multiple channels with an input current range of 10 muA to 80 muA. The main blocks in the ADC include a current ramp generator, multiple current comparators and a 12-bit Gray code counter. Simulation results are presented that predict 12-bit resolution, sampling rates up to 20 Ksps, and a per-channel power consumption of less than 2 mW using a Wilkinson architecture with 8 channels.