Iranian Journal of Biomedical Engineering (IJBME)
نشریه علمی مهندسی پزشکی زیستی

Design of a Low Noise and Low Offset Operational Amplifier Using Chopper Stabilization Technique for Biopotential Recording Applications

Document Type : Full Research Paper

Authors

Vahid Zal
Hamidreza Rezaee-Dehsorkh
Nassim Ravanshad

Integrated Circuit Lab., Faculty of Electrical and Biomedical Engineering, Sadjad University, Mashhad, Iran

https://doi.org/10.22041/ijbme.2025.2048617.1940
Abstract
Noise reduction and DC offset cancellation are two of the main challenges in the design of biopotential recording amplifiers. One common method for reducing operational amplifier flicker noise and offset is to use the chopper - stabilized technique. Switch charge injection, long settling time, and ripple are the main drawbacks of using chopper amplifiers. The proposed circuit uses capacitive coupling to eliminate the ripple that the offset of the chopping amplifier induces. Also, a feedback circuit is used to prevent the saturation of the chopping amplifier, while a rail - to - rail input common - mode range is guaranteed. The proposed circuit is suitable for low - power applications such as wearable medical instruments. The proposed circuit is designed in a 180 nm CMOS technology with a 1.8 V supply voltage. Simulation results show a power consumption of 23 µW and a noise voltage spectral density of 44.5 nV/√Hz.

Keywords

Operational amplifier
Offset
Flicker noise
Chopper stabilized
Biomedical instrumentation amplifier

Subjects

Iranian Journal of Biomedical Engineering (IJBME)
Volume 18, Issue 4
Winter 2025
Pages 329-342

  • Receive Date 21 December 2024
  • Revise Date 19 April 2025
  • Accept Date 16 May 2025

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