Voltage Control Ratiometric Readout Technique With Improved Dynamic Range and Power-Efficiency for Open-Loop MEMS Capacitive Accelerometer
Voltage Control Ratiometric Readout Technique With Improved Dynamic Range and Power-Efficiency for Open-Loop MEMS Capacitive Accelerometer
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DOI：
10.1109/tcsi.2022.3202786
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发表时间：
2022-09-05
影响因子：
5.1
通讯作者：
Zhu, Zhangming
中科院分区：
文献类型：
--
作者：
Zhong, Longjie;Liu, Shubin;Zhu, Zhangming
面向物联网应用的MEMS电容式加速度计采用开环结构而非闭环结构，以实现低功耗。在开环结构中，电压控制读出技术是低成本的首选。然而，电压控制读出技术遭受低动态范围和低功率效率（就FoM而言）。本文提出了一种压控比率读出技术，以提高动态范围和功率效率。VCR读出技术在0.18 μ m1.8V/5.0VCMOS工艺的读出电路中得到了验证。与采用相同CMOS工艺制作并使用相同敏感元件测试的传统电压读出电路相比，VCR读出电路的全输入信号范围提高了3.5dB（从+/- 8到+/-12 g），本底噪声提高了9.5dB（从804 μ g/root Hz到270 μ g/root Hz）。动态范围从44.0dB提高到57.0dB，FoM（1）从3100提高到830，FoM（2）从1977 μ W提高到1977 μ W。μ g/Hz至796 μ W。μ g/Hz。
MEMS capacitive accelerometer for the Internet of Things (IoT) applications is designed with open-loop structure rather than closed-loop structure to achieve low power consumption. In the open-loop structure, voltage control readout technique is preferred for low cost. However, the voltage control readout technique suffers from low dynamic range and low power efficiency (in terms of FoM). In this paper, the voltage control ratiometric (VCR) readout technique is proposed to improve both dynamic range and power efficiency. The VCR readout technique is demonstrated in a readout circuit fabricated in a commercial 0.18um 1.8V/5.0V CMOS process. Compared to the traditional voltage readout circuit fabricated with the same CMOS process and tested with the same sensing element, the VCR readout circuit improves full input signal range by 3.5dB (from +/- 8 to +/- 12g ) and the noise floor by 9.5dB (from 804 mu g/root Hz to 270 mu g/root Hz). As a result, the dynamic range is improved by 13.0dB (from 44.0dB to 57.0dB), the FoM(1) is improved from 3100 to 830 and the FoM(2) is improved from 1977 mu W . mu g/Hz to 796 mu W . mu g/Hz.