Department of Biosystems Science and Engineering, ETH Zürich, 4058 Basel, Switzerland.
Section Bioelectronics, TU Delft, 2628 CD Delft, The Netherlands.
Sensors (Basel). 2021 Sep 27;21(19):6456. doi: 10.3390/s21196456.
This article reports on a compact and low-power CMOS readout circuit for bioelectrical signals based on a second-order delta-sigma modulator. The converter uses a voltage-controlled, oscillator-based quantizer, achieving second-order noise shaping with a single opamp-less integrator and minimal analog circuitry. A prototype has been implemented using 0.18 μm CMOS technology and includes two different variants of the same modulator topology. The main modulator has been optimized for low-noise, neural-action-potential detection in the 300 Hz-6 kHz band, with an input-referred noise of 5.0 μV, and occupies an area of 0.0045 mm. An alternative configuration features a larger input stage to reduce low-frequency noise, achieving 8.7 μV in the 1 Hz-10 kHz band, and occupies an area of 0.006 mm. The modulator is powered at 1.8 V with an estimated power consumption of 3.5 μW.
本文报道了一种基于二阶 delta-sigma 调制器的生物电信号紧凑型低功耗 CMOS 读出电路。该转换器采用基于电压控制振荡器的量化器，通过单个无运算放大器的积分器和最小化的模拟电路实现二阶噪声整形。使用 0.18μm CMOS 技术实现了一个原型，其中包括相同调制器拓扑的两种不同变体。主调制器针对 300 Hz-6 kHz 频段的低噪声神经动作电位检测进行了优化，输入参考噪声为 5.0 μV，占用面积为 0.0045 mm。另一种配置具有更大的输入级，可降低低频噪声，在 1 Hz-10 kHz 频段实现 8.7 μV 的噪声，占用面积为 0.006 mm。调制器在 1.8 V 电压下工作，估计功耗为 3.5 μW。
