Ultra-Low Power Programmable Bandwidth Capacitively-Coupled Chopper Instrumentation Amplifier Using 0.2 V Supply for Biomedical Applications

• Published in: Journal of low power electronics and applications Vol. 13; no. 2; p. 37
• Main Authors: Pham, Xuan Thanh, Kieu, Xuan Thuc, Hoang, Manh Kha
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2023
• Subjects: Amplifiers; Bandwidths; biomedical amplifier; Biomedical materials; chopper amplifier; Closed loops; Design; Efficiency; Feedback; Instruments; low noise; Power consumption; Power efficiency; Rejection; Sensors; Signal processing; Technology application; Thermal noise; Transistors; ultra-low power
• ISSN: 2079-9268; 2079-9268
• DOI: 10.3390/jlpea13020037

This paper presents a capacitively coupled chopper instrumentation amplifier (CCIA) with ultra-low power consumption and programmable bandwidth for biomedical applications. To achieve a flexible bandwidth from 0.2 to 10 kHz without additional power consumption, a programmable Miller compensation technique was proposed and used in the CCIA. By using a Squeezed inverter amplifier (SQI) that employs a 0.2-V supply, the proposed CCIA addresses the primary noise source in the first stage, resulting in high noise power efficiency. The proposed CCIA is designed using a 0.18 µm CMOS technology process and has a chip area of 0.083 mm2. With a power consumption of 0.47 µW at 0.2 and 0.8 V supply, the proposed amplifier architecture achieves a thermal noise of 28 nV/√Hz, an input-related noise (IRN) of 0.9 µVrms, a closed-loop gain (AV) of 40 dB, a power supply rejection ratio (PSRR) of 87.6 dB, and a common-mode rejection ratio (CMRR) of 117.7 dB according to post-simulation data. The proposed CCIA achieves a noise efficiency factor (NEF) of 1.47 and a power efficiency factor (PEF) of 0.56, which allows comparison with the latest research results.