A 4.0-μVrms 7.5-kHz-BW Neural Signal Recording Circuit for Closed-Loop Deep Brain Stimulation
- Resource Type
- Conference
- Authors
- Tian, Ruizhi; Zhou, Fei; Xia, Qingjiang; You, You; Lu, Wengao; Zhang, Yacong; Chen, Zhongjian
- Source
- 2023 8th International Conference on Integrated Circuits and Microsystems (ICICM) Integrated Circuits and Microsystems (ICICM), 2023 8th International Conference on. :275-279 Oct, 2023
- Subject
- Components, Circuits, Devices and Systems
Signal Processing and Analysis
Integrated circuits
Satellite broadcasting
Deep brain stimulation
Switches
Frequency response
Recording
Timing
low noise
biosignal acquisition
neural interface
neural signal recording
biomedical electronics
- Language
This work presents a low-noise biosignal acquisition application-specific integrated circuit (ASIC) for neural signal recording in closed-loop deep brain stimulation (DBS). An ac-coupled low-noise amplifier (LNA) amplifies the signals of interest while removing the low-frequency electrode offset. An improved programmable-gain amplifier (PGA) employs a flip-over-capacitor structure to prevent the degeneration of frequency response from switches’ off-state resistance. The differential-difference amplifier (DDA) used in the PGA isolates the switching noise from the following switched-capacitor low-pass filter that defines the upper limit of the bandwidth. A 12-bit analog-to-digital converter (ADC) converts the signals to digital representations with a sampling rate of 21.5 kS/s. The proposed circuit was fabricated in a 180 nm CMOS process with an area of 0.576 mm 2 , consuming 60 μA under a 1.8-V supply. It achieves a programmable gain from 47.3 dB to 59.1 dB. The measured input-referred noise is 1.74 μV rms (1 Hz–300 Hz) and 3.73 μV rms (300 Hz–7.5 kHz). The ADC used for digitization achieves an ENOB of 10.63 bits.