A Slim Needle Neural Probe with 160 Active Recording Sites and Selectable ADCs

In order to provide active neural needle probes with a large number of recordings sites integrated on a single shank, a high degree of miniaturization of the probe shank and its electronics is required. This work presents a probe which comprises 160 recording sites each combined with a low-noise amplifier integrated under each electrode in an area of only 50×80 µm2. In total, 32 channels can be monitored simultaneously by means of 32 12-bit incremental Delta-Sigma ADCs each requiring an area of 120×40 µm2. The selection of the 32 channels is performed by means of a digital controller. The average input referred noise for AP signals (300 Hz to 10 kHz) is extracted to 20.87 µVrms in in-vitro measurements. The design competes well with the state of the art due to a maximum shank width of 200 µm, an area of 0.032 mm2, and a power consumption of 26.5 µW per channel.