Integrated circuit for neural recording and stimulation

A 16 channel neural signal measurement and stimulation system is presented. All 16 channels can be used in a measurement setup that simultaneously both stimulates and measures neurons. The amplifying stage consists of 16 preamplifiers, a multiplexer and two post-amplifiers. The measured signal is digitized with a 10-bit SAR A/D converter. The circuit contains control logic for buffering the measured results and inserting them into a SPI-bus. The logic also controls the circuit´s bias currents, high-pass corner frequency, post-amplifier gains and stimulation current strengths. Amplifying gain can be configured from 100 to 5000. The mixed-signal circuit is implemented with 0.35 μm IC process by ams AG. The circuit is estimated to consume from 900 μW to 5 mW power, depending on the SPI-bus clock speed and amplifying gain.