Extended counting ADC for 32-channel neural recording headstage for small animals

Extended counting analog-to-digital converter (ECADC) combines the accuracy of delta-sigma modulation and the speed of algorithmic conversion. This conversion architecture is shown to be useful in biomedical applications, where both resolution and speed are demanded. This work presents a design of ECADC for 32 neural recording channels. Several power optimizing methods are described. The designed converter achieves a resolution of 13 bits and a sampling frequency of 512 kHz. With 3.3 V supply, the total power consumption is estimated to be 7 mW. The whole system including 32 neural recording channels is fitted in an area of 3 mm times 3 mm in 0.5 mum CMOS process.