A Low-Noise, Low-Power Amplifier With Current-Reused OTA for ECG Recordings

作者：Zhang, Jie; Zhang, Hong^*; Sun, Quan; Zhang, Ruizhi

来源：IEEE Transactions on Biomedical Circuits and Systems, 2018, 12(3): 700-708.

DOI：10.1109/TBCAS.2018.2819207

• Bio-signal amplifier
• class-AB
• current-reused
• ECG recording
• inverter-based
• low noise
• low power

This paper presents a low-power and low-noise capacitive-feedback amplifier with a current-reused OTA for ECG recordings. To improve the noise-power efficiency, the proposed OTA employs a current-reused architecture, which adopts an inverter-based differential input stage for low noise, and a class-AB output stage for large output range and high g(m) /I efficiency. The driving branch of the class-AB output stage is merged into the input stage to realize current reuse and reduce power consumption further. Fabricated in a 0.35-mu mCMOS process, the amplifier consumes 160 nA from a 2-V supply, while achieving an input-referred noise of 2.05 mu V-rms, corresponding to a noise efficiency factor (NEF) of 2.26. The measured common-mode rejection ratio (CMRR) and power supply rejection ratio (PSRR) exceed 65 dB and 70 dB, respectively. The total harmonic distortion (THD) is less than 1% with a 15-mV(pp) input at 20 Hz and the active area is 0.3 mm x 0.6 mm.

• 出版日期2018-6
• 单位西安交通大学