A Wide Input Range, Low-noise Neural Recording Amplifier IC With Adaptive Gain Control and Common-mode Cancellation Loop

• Published in: Journal of semiconductor technology and science Vol. 25; no. 4; pp. 397 - 405
• Main Authors: Park, Boseong, Hong, Soonseong, Cha, Hyouk-Kyu
• Format: Journal Article
• Language: English
• Published: 대한전자공학회 31.08.2025
• Subjects: 전기공학
• ISSN: 1598-1657; 2233-4866
• DOI: 10.5573/JSTS.2025.25.4.397

This paper proposes a wide input range, low-noise neural recording amplifier IC with adaptive gain control and a feedback-based common-mode cancellation loop (CMCL) for bidirectional neuromodulation applications. The proposed amplifier operates with maximum gain and excellent noise performance under normal conditions, while automatically reducing its gain to extend the dynamic range (DR) and activating the CMCL in response to differential-mode (DM) and common-mode (CM) stimulation artifacts, respectively, thereby adjusting the DM gain to prevent amplifier saturation and removing the CM component. The total harmonic distortion (THD) of the circuit output is 0.822% with a 77 mVPP DM input at a gain of 17.72 dB and 0.418% in the presence of a 1 VPP CM artifact. Under ideal conditions, the amplifier maintains a gain of 40 dB with an input-referred noise (IRN) performance of 2.32 µVrms over a bandwidth of 1 Hz to 10 kHz. The CMCL dynamically toggles on or off depending on the presence of artifacts to balance noise performance and artifact tolerance. The proposed amplifier is designed using 180 nm CMOS process, consumes 2 µW at 1-V supply, and occupies 0.36 mm² of die area. KCI Citation Count: 0