Silicon neural recording arrays with on-chip electronics for in-vivo data acquisition

This paper describes a 64 site, 8 channel silicon microelectrode for single-unit neural recording. The probe features integrated CMOS circuitry for electronic positioning of the active recording sites with respect to active neurons. On-chip capacitively coupled pre-amplifiers eliminate the DC baseline polarization of the electrode while providing a per channel gain of 1000. Time-division multiplexing circuitry is provided for sampling the 8 active channels onto one data lead. The on-chip circuitry consumes 834 μW of power from ±1.5 V supplies and occupies 4.34 mm² of die area. The probe is fabricated using an 18 mask, single-sided, micromachined CMOS process with a 3 μm minimum feature size