IEEE Trans Biomed Circuits Syst. 2015 Apr;9(2):237-47. doi: 10.1109/TBCAS.2015.2417124. Epub 2015 Apr 14.
This paper presents a low-voltage current-reuse chopper-stabilized frontend amplifier for fetal ECG monitoring. The proposed amplifier allows for individual tuning of the noise in each measurement channel, minimizing the total power consumption while satisfying all application requirements. The low-voltage current reuse topology exploits power optimization in both the current and the voltage domain, exploiting multiple supply voltages (0.3, 0.6 and 1.2 V). The power management circuitry providing the different supplies is optimized for high efficiency (peak charge-pump efficiency = 90%).The low-voltage amplifier together with its power management circuitry is implemented in a standard 0.18 μm CMOS process and characterized experimentally. The amplifier core achieves both good noise efficiency factor (NEF=1.74) and power efficiency factor (PEF=1.05). Experiments show that the amplifier core can provide a noise level of 0.34 μVrms in a 0.7 to 182 Hz band, consuming 1.17 μW power. The amplifier together with its power management circuitry consumes 1.56 μW, achieving a PEF of 1.41. The amplifier is also validated with adult ECG and pre-recorded fetal ECG measurements.
本文提出了一种用于胎儿心电图监测的低压电流复用斩波稳定前端放大器。所提出的放大器允许对每个测量通道的噪声进行单独调整，在满足所有应用要求的同时，将总功耗降至最低。低压电流复用拓扑结构在电流和电压域中都利用了功率优化，采用了多个电源电压（0.3、0.6 和 1.2 V）。为不同电源提供的电源管理电路针对高效率进行了优化（峰值电荷泵效率=90%）。低压放大器及其电源管理电路采用标准 0.18 μm CMOS 工艺实现，并进行了实验表征。放大器核心实现了良好的噪声效率因子（NEF=1.74）和功率效率因子（PEF=1.05）。实验表明，放大器核心在 0.7 至 182 Hz 带宽内可提供 0.34 μVrms 的噪声水平，消耗 1.17 μW 功率。放大器及其电源管理电路共消耗 1.56 μW，实现了 1.41 的 PEF。还使用成人 ECG 和预记录的胎儿 ECG 测量对放大器进行了验证。
