A Low-Power Low-Noise Capacitively-Coupled Chopper Instrumentation Amplifier Using a Switched Capacitor DC Servo Loop

Xuan Phuong Tran; Duc Dung Nguyen; Duy Phong Pham; Manh Kha Hoang; Xuan Thanh Pham

doi:10.48084/etasr.15756

Authors

Xuan Phuong Tran School of Electrical and Electronic Engineering, Hanoi University of Industry, Hanoi, Vietnam
Duc Dung Nguyen School of Electrical and Electronic Engineering, Hanoi University of Industry, Hanoi, Vietnam
Duy Phong Pham Faculty of Electronic and Telecommunication Engineering, Electric Power University, Hanoi, Vietnam
Manh Kha Hoang School of Electrical and Electronic Engineering, Hanoi University of Industry, Hanoi, Vietnam
Xuan Thanh Pham School of Electrical and Electronic Engineering, Hanoi University of Industry, Hanoi, Vietnam

Volume: 16 | Issue: 3 | Pages: 35579-35585 | June 2026 | https://doi.org/10.48084/etasr.15756

Received: 24 October 2025 | Revised: 17 March 2026 and 29 March 2026 | Accepted: 9 April 2026 | Online: 6 June 2026
Corresponding author: Xuan Thanh Pham

Abstract

This paper presents a Capacitively-Coupled Chopper Amplifier (CCIA) using a Switched Capacitor DC Servo Loop (SC-DSL) to achieve low noise and low power consumption in signal amplification bandwidth for biomedical applications. The CCIA effectively mitigates the effects of mismatch and flicker noise (1/f). At the same time, the SC-DSL maintains a balanced electrode bias at the input and facilitates the efficient amplification of signals, such as Electrocardiography (ECG) and Electroencephalography (EEG), free from interference caused by variations in electrode material and size. The simulation results, utilizing 180 nm CMOS technology, indicate that the proposed design occupies an area of 0.04 mm². The CCIA has a low power consumption of 1.75 µW and low Input-Referred Noise (IRN) of 1.02 µV_rms from a voltage supply of 1 V. By using the SC-DSL, the CCIA can be operated with an input electrode offset of up to 50 mV. Furthermore, the operational bandwidth attained 7.64 kHz.

Keywords:

CCIA, low noise, electrode offset, DC servo loop, switched-capacitor

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