A Low-Noise Ex-Vivo CMOS MEA with 4k Recording Sites, 4k Recording Channels, and 1k Stimulation Sites

A Multi-Electrode-Array (MEA) in a 180 nm CMOS technology is presented with 4225 recording sides, 4225 recording channels, and 1024 stimulation sites. The two versions of the chip provide active areas of 2.3 mm x 2.3 mm and 4.1 mm x 4.1 mm with a spacial recording site resolution of 36 µm and 64 µm, respectively. The devices are capable of full imaging at a frame rate of 25 kHz at an input-referred noise of 13.1 µVrms in the action potential (AP) band from 300 Hz to 10 kHz, 10 µVrms in the AP band from 300 Hz to 6 kHz, and 15.1 µVrms in the local field potential (LFP) band from 1 Hz to 300 Hz. To reach these noise levels the signals from the recording sites are routed out of the active array to dedicated low noise amplifiers in the periphery. Crosstalk between the related pixels is significantly reduced by individual actively shielded traces.