Main Parameters Uniformity Enhancement in Multichannel Integrated Circuits Dedicated to Biomedical Signals Recordings

This paper presents an approach for main parameters uniformity improvement from channel to channel in integrated circuit dedicated to multi-point neurobiological recordings. We show that if the conditioning channel size and power consumption are very limited, additional correction circuits are necessary to key parameters spread lowering. The method has been implemented in a 64-channel circuit fabricated in 180 nm CMOS technology and resulted in tenfold reduction of corner frequency spread (from 59% down to 4%) and fourfold reduction of DC offset (from 31.6% down to 7.5%). The correction circuit has also been used in a novel optimization method which allows for more than 30 dB Common Mode Rejection Ratio increase. It is also worth mentioning that the proposed methodology is very efficient and has minor impact on the overall channel size and power consumption A single recording channel consumes 8.5 μW of power and occupies 0.065 mm2 of silicon area while its Input Referred Noise is equal to 5μV RMS .