A Reconfigurable Neural Recording Front-End IC for Multimodal Operation

This paper presents a reconfigurable neural recording front-end integrated circuit (IC) for multimodal operation. The proposed IC performs the voltage sensing to acquire the electrical neural signal and detects the photodiode current to monitor the concentration of calcium ions in the neuronal cell population. The front-end IC is composed of the analog front- end, voltage-to-current converters, path switches, and current-to- digital converters for recording voltage and current signals. When monitoring the electrical neural activity, the IC is configured to operate in the voltage sensing mode. When reading the photodiode current, the IC operates in the current sensing mode. The proposed front-end IC is designed using a 180-nm CMOS process. The neural recording IC consumes the power of 5.4.W/channel and 2.W/channel in the voltage and current sensing modes, respectively. The active area occupied by the single-channel circuit is 0.23 mm(2).