A 5.5 μW 42nV/√Hz Chopper stabilized Amplifier for Biomedical Application with Input Impedance Enhancement



The continuous real-time monitoring of diverse physical parameters using biosignals like ECG and EEG requires the biomedical sensors. Such sensor consists of analog frontend unit for which low noise and low power Operational transconductance amplifier (OTA) is essential. In this paper, the novel chopper-stabilized bio-potential amplifier is proposed. The chopper stabilization technique is used to reduce the offset and flicker noise. Further, the OTA is likewise comprised of a method to enhance the input impedance without consuming more power. Also, the ripple reduction technique is used at the output branch of the OTA. The designed amplifier consumes 5.5 μW power with the mid-band gain of 40dB. The pass-band for the designed amplifier is 0.1Hz to 1KHz. The input impedance is likewise boosted with the proposed method. The noise is 42 nV/√Hz with CMRR of 82 dB. All simulations are carried out in 180nm parameters.


Chung Jae Lee and Jong In Song. A Chopper Stabilized Current-

Feedback Instrumentation Amplifier for EEG Acquisition Applications.

IEEE Access, 7:11565–11569, 2019.

Swati Chauhan and Lalit Mohan Saini. Low Power and Low Noise

Instrumentation Amplifier. Proceedings of the 2nd International Conferenceon Intelligent Computing and Control Systems, ICICCS 2018,

(Iciccs):1332–1335, 2019.

Yuriy Agrich, Vadim Lifshits, Yuriy Pavlyuk, Ilya Gureev, and Daniil

Vorobyev. CMOS amplifier with Chopper Stabilization and Offset

Calibration. Proceedings of the 2020 IEEE Conference of Russian Young

Researchers in Electrical and Electronic Engineering, EIConRus 2020,

pages 2336–2339, 2020.

Reid R. Harrison and Cameron Charles. A low-power low-noise CMOS

amplifier for neural recording applications. IEEE Journal of Solid-State

Circuits, 38(6):958–965, 2003.

Hyunsoo Ha, Chris Van Hoof, and Nick Van Helleputte. Measurement

and Analysis of Input-Signal Dependent Flicker Noise Modulation in

Chopper Stabilized Instrumentation Amplifier. IEEE Solid-State Circuits

Letters, 1(4):90–93, 2018.

Chung Jae Lee and Jong In Song. A Chopper-Stabilized Amplifier with

a Tunable Bandwidth for EEG Acquisition Applications. IEEE Access,

:73165–73171, 2019.

Arezu Bagheri, Muhammad Tariqus Salam, Jose Luis Perez Velazquez,

and Roman Genov. Low-Frequency Noise and Offset Rejection in DCCoupled Neural Amplifiers: A Review and Digitally-Assisted Design

Tutorial. IEEE Transactions on Biomedical Circuits and Systems,

(1):161–176, 2017.

Hariprasad Chandrakumar and Dejan Markovic. A High Dynamic-

Range Neural Recording Chopper Amplifier for Simultaneous Neural

Recording and Stimulation. IEEE Journal of Solid-State Circuits,

(3):645–656, 2017.

Xiao Yang, Jing Yang, Li Fen Lin, and Chao Dong Ling. Low-power

low-noise CMOS chopper amplifier. Proceedings - 2010 International

Conference on Anti-Counterfeiting, Security and Identification, 2010

ASID, pages 83–84, 2010.

Jiangchao Wu, Man Kay Law, Pui In Mak, and Rui P. Martins. A 2-W

-nV/√Hz Readout Front End with Multiple-Chopping Active-High-

Pass Ripple Reduction Loop and Pseudofeedback DC Servo Loop. IEEE

Transactions on Circuits and Systems II: Express Briefs, 63(4):351–355,

Yuhwai Tseng, Yingchieh Ho, Shuoting Kao, and Chauchin Su. A 0.09

W low power front-end biopotential amplifier for biosignal recording.

IEEE Transactions on Biomedical Circuits and Systems, 6(5):508–516,

Fan Qinwen, F Sebastiano, J H Huijsing, and K A A Makinwa. A

8 W 60 nV/√Hz Capacitively-Coupled Chopper Instrumentation

Amplifier in 65 nm CMOS for Wireless Sensor Nodes. Solid-State

Circuits, IEEE Journal of, 46(7):1534–1543, 2011.

Manish Goswami and Smriti Khanna. DC suppressed high gain active

CMOS instrumentation amplifier for biomedical application. 2011 International Conference on Emerging Trends in Electrical and Computer

Technology, ICETECT 2011, pages 747–751, 2011.

Hariprasad Chandrakumar and Dejan Markovi´c. A simple area-efficient ripple-rejection technique for chopped biosignal amplifiers. IEEE

Transactions on Circuits and Systems II: Express Briefs, 62(2):189–193,

Ankit Adesara and Amisha Naik. A Low noise Low power Chopper

Stabilized Biopotential Amplifier for Biomedical Applications.

Jesse Coulon. a Low Power Low Noise Instrumentation Amplifier for

Ecg Recording Applications. (May):107, 2012.

P. Bruschi, F. Del Cesta, A. N. Longhitano, M. Piotto, and R. Simmarano. A very compact CMOS instrumentation amplifier with nearly

rail-to-rail input common mode range. European Solid-State Circuits

Conference, pages 323–326, 2014.

Geok Teng Ong and Pak Kwong Chan. A power-aware chopperstabilized instrumentation amplifier for resistive wheatstone bridge sensors. IEEE Transactions on Instrumentation and Measurement,

(9):2253–2263, 2014.






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