64 Channel ASIC for Neurobiology Experiments

This paper presents the design and measurements of 64 channel Application Specific Integrated Circuits (ASIC) for recording signals in neurobiology experiments. The ASIC is designed in 180 nm technology and operates with ± 0.9 V supply voltage. Single readout channel is built of AC coupling circuit at the input and two amplifier stages. In order to reduce the number of output lines, the 64 analogue signals from readout channels are multiplexed to a single output by an analogue multiplexer. The gain of the single channel can be set either to 350 V/V or 700 V/V. The low and the high cut-off frequencies can be tuned in 9 ÷ 90 Hz and in the 1.6 ÷ 24 kHz range respectively. The input referred noise is 7 µV rms in the bandwidth 90 Hz - 1.6 kHz and 9 µ V rms in the bandwidth 9 Hz - 24 kHz. The single channel consumes 200 µW of power and this together with other parameters make the chip suitable for recording neurobiology signals.