Low Noise, High Input Impedance Digital-Analog Hybrid Offset Suppression Amplifier for Wearable Dry Electrode ECG Monitoring
Low Noise, High Input Impedance Digital-Analog Hybrid Offset Suppression Amplifier for Wearable Dry Electrode ECG Monitoring
复制标题
用于可穿戴干电极心电图监测的低噪声、高输入阻抗数模混合偏移抑制放大器
DOI：
10.3390/electronics9010165
复制
发表时间：
2020-01-01
期刊：
影响因子：
2.9
通讯作者：
Li，Haiou
中科院分区：
文献类型：
--
作者：
Xu，Weilin;Wang，Taotao;Li，Haiou
便携式实时心电图（ECG）是一种方便、有发展前途的心血管疾病电子设备。然而，与传统临床应用的湿凝胶电极不同，干电极能够胜任舒适的长时间佩戴，并且可以防止皮肤溃疡。它的超高源阻抗和电极偏置（EOS）使得传统的低输入阻抗和有限EOS范围的斩波放大器难以应用于该领域。为了克服这些挑战，本文提出了一种新的斩波放大器拓扑结构。该架构包括增益控制回路、纹波减小回路和直流伺服回路（DSL）。所提出的采样输入级和数模混合DSL用于提高输入阻抗和扩展EOS处理范围。该斩波电容耦合仪器放大器采用0.18µm 1P6M 1.8 V CMOS盐化工艺设计，可实现120 GΩ （<0.05 Hz）或2.1 GΩ （0.6~250 Hz）的超高输入阻抗，±325 mV的EOS处理范围和0.6~250 Hz的低噪声1.9 μVrms。它占地0.36 mm2，仅消耗11 μA的静态电流。
The portable real-time electrocardiogram (ECG) is a convenient and promising electronic device for cardiovascular diseases patients. However, unlike wet gel electrodes in traditional clinical applications, dry electrodes are competent for comfortable long-time wearing and can prevent skin ulceration. Its ultra-high source impedance and electrode offset (EOS) make traditional chopper amplifiers with low input impedance and limited EOS range difficult to apply to this area. To overcome these challenges, this paper proposes a novel chopper amplifier topology. This architecture includes a gain control loop, a ripple reduction loop, and a DC-servo loop (DSL). The proposed sampling input stage and digital-analog hybrid DSL are employed to boost input impedance and extend the EOS handing range. Designed with a 0.18 µm 1P6M 1.8 V CMOS salicide process, the proposed chopper capacitively coupled instrumentation amplifier achieves an ultra-high input impedance of 120 GΩ (<0.05 Hz) or 2.1 GΩ (0.6~250 Hz), an EOS handing range of ±325 mV and a low noise of 1.9 μVrms at 0.6~250 Hz. It occupies an area of 0.36 mm2 and only consumes a quiescent current of 11 μA.