This paper presents a compact DDA-based fully-differential CMOS instrumentation amplifier dedicated for micro-power ECG monitoring. Only eight transistors are employed to realize a power-efficient current-sharing DDA. A RC network (using MOS pseudo resistors and poly capacitors) forms feedback loops around the DDA creating an ac-only amplification. The proposed amplifier is dc-coupled via gate terminals of the p-channel input transistors. It thus achieves sufficiently high input impedance over the entire ECG frequency range. Fabricated in a 0.35-μm CMOS process, the proposed amplifier occupies 0.0712 mm ² . It operates from a 2 V dc supply with 336 nA current consumption. Measurements show that the amplifier attains its input impedance of 57.5 MΩ at 150 Hz and achieves 1.54 μV _rms input-referred noise over 0.1-300 Hz. Noise and power efficiency factors are 2.02 and 8.16, respectively. At 50 Hz, the mean CMRR of 83.24 dB is obtained from 11-chip measurement. Experiments performed on a human subject confirm the functionality of the proposed amplifier in a real measurement scenario.

中文翻译：

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具有 57.5-MΩ Zin、2.02 NEF、8.16 PEF 和 83.24-dB CMRR 的紧凑型 Sub-μW CMOS ECG 放大器

本文介绍了一种基于 DDA 的紧凑型全差分 CMOS 仪表放大器，专用于微功率 ECG 监测。仅使用八个晶体管来实现高能效均流 DDA。一种RC 网络（使用 MOS 伪电阻器和多晶硅电容器）在 DDA 周围形成反馈回路，从而创建仅交流放大。建议的放大器通过 p 沟道输入晶体管的栅极端子直流耦合。因此，它在整个 ECG 频率范围内实现了足够高的输入阻抗。建议的放大器采用 0.35-μm CMOS 工艺制造，占用 0.0712 mm ² 。它由 2 V 直流电源供电，电流消耗为 336 nA。测量结果表明，放大器在 150 Hz 时达到 57.5 MΩ 的输入阻抗，并达到 1.54 μV _rms输入参考噪声超过 0.1-300 Hz。噪声和功率效率因子分别为 2.02 和 8.16。在 50 Hz 时，83.24 dB 的平均 CMRR 是从 11 片测量中获得的。对人体进行的实验证实了所提出的放大器在实际测量场景中的功能。