Analogue multiplexer for neural application in 180 nm CMOS technology

This paper presents the architecture and the results of preliminary tests of the analogue multiplexer used in a multichannel ASIC for recording signals from neural systems. This integrated circuit is designed in CMOS 180 nm technology. The core of the ASIC consists of 64 analogue channels equipped with a band-pass filter. The cut-off frequencies of the band-pass filter are in the range from 1 Hz to 15 kHz. In order to reduce the number of outputs, the 64 analogue channels are multiplexed to the single output by analogue 64:1 multiplexer. The nominal frequency of the multiplexer is 2.5 MHz which results in 30 kHz sampling rate per single channel. During the design the special attention was paid to minimize the problem of switching noise in mixed-mode integrated circuit.