Low noise and low power multichannel integrated circuit for recording neural spikes and LFP signals

We present the design and measurement results of the multichannel ASIC dedicated for neurobiology experiments. Chip is fabricated in CMOS 180nm technology and comprises 64 channels. A single readout channel is able to record both neural spikes and LFP (Local Field Potential) signals. Each channel is equipped with digital registers responsible for controlling its voltage gain, low and high cut-off frequencies, and voltage offsets of the recording channel. Thanks to these registers user is able either to set parameters of each channel independently with respect to the specific requirements of neurobiology experiments or to correct the mismatch effects in a multichannel system. The low cut-off frequency of the recording channel may be changed in the 60 mHz - 100 Hz range, the high cut-off frequency can be set to 4.7 kHz or 12 kHz while the voltage gain may be set to 139 V/V or to 1100 V/V. Single recording channel consumes only 25 μW of the power from ± 0.9 V voltage supply, its input referred noise is on the 3.7 μV level and it occupies 0.13 mm2 of the silicon area.