A Low-Noise, Low-Power Neural Signal Amplifier for Deep Brain Stimulation System Chips Tolerating 3V Stimulation

In this paper, a power-efficient low-noise LFP/AP recording analog front end with real-time stimulation artifact removal is proposed. During closed-loop stimulations, the artifact removal is realized through AB-IPC (Artifact Blanking Input Protection Circuit) by blanking the front end with a clock synchronized to the stimulation-enable signal. After stimulation, the proposed front-end can quickly recover back to recording mode. Furthermore, to prevent amplifier saturation due to sudden signals, we have utilized an adjustable gain design, including modes with 45, 50, and 60dB selection. In terms of adjustable bandwidth, the high-pass corner frequency ranges from 0.614 - 300Hz, and the low-pass corner frequency is 6.7kHz. Through chopping stabilization techniques, input equivalent noise reaches 0.89uVrms in the 0.5Hz-300Hz and 2.55uVrms in the 300-5kHz frequency bands, while power consumption remains within the range of 3.95uW. It is shown that the proposed AFE acquisition circuit is suitable for implantable closed-loop DBS (Deep Brain Stimulation) control systems.