收稿日期: 2009-04-13
修回日期: 2009-05-04
网络出版日期: 2009-11-15
基金资助
国家高技术研究发展计划项目(2007AA04Z349)资助
A low-noise and low-offset capacitive readout circuit
Received date: 2009-04-13
Revised date: 2009-05-04
Online published: 2009-11-15
吴其松 , 杨海钢 , 张翀 , 尹韬 . 一种低噪声低失调电容读出电路[J]. 中国科学院大学学报, 2009 , 26(6) : 789 -794 . DOI: 10.7523/j.issn.2095-6134.2009.6.009
This paper presents a novel structure of capacitive readout circuit for fully differential capacitive sensor. The operation of this circuit is controlled by a nonoverlapping two-phase clock. This circuit is not sensitive to parasitic capacitor. Using correlated double sampling(CDS), the low-frequency noise and voltage offset have been suppressed, so that the resolution and dynamic range of the circuit have been improved. The experiment chip has been fabricated in the standard 0.35μm CMOS process, with a single 5V power supply, and the die size is 0.7mm×1.8mm. The results show that the readout circuit achieves a resolution of 0.4aF/√Hz with 118dB dynamic range under 1MHz sampling frequency.
Key words： capacitive sensor; capacitive readout circuit; CDS
[1] Zhu W, Zhang J M, Xiong B, et al. Research of detecting technique of micro differential capacitance
[J]. Journal of Test and Measurement Technology, 2004, 18(3):203-207(in Chinese). 朱 武,张佳民,熊 斌,等. 微小差分电容检测技术的研究
[J]. 测试技术学报,2004,18(3):203-207.
[2] Wu X Z, Xiao D B, Li S Y. Research of closed-loop detection technology for capacitive microaccelerometer
[J]. Chinese Journal of Sensors and Actuators, 2006, 19(4):1097-1100(in Chinese). 吴学忠,肖定邦,李圣怡. 电容式微加速度计的闭环检测技术研究
[J]. 传感技术学报,2006,19(4):1097-1100.
[3] Yin T, Yang H G. Study on MEMS precision capacitive readout circuits design
[J]. Chinese Journal of Electron Devices, 2007,30(4):1188-1193(in Chinese). 尹 韬,杨海钢. MEMS高精度电容读出电路的单芯片集成研究
[J]. 电子器件,2007,30(4):1188-1193.
[4] Wu J F. Sensing and control electronics for low mass low capacitance MEMS accelerometers . Doctoral Dissertation, Carnegie Mellon University, 2002.
[5] Jiang X S. Capacitive position sensing interface for micromachine inertial sensors . Berkeley:Doctoral Dissertation, University of California,2002.
[6] Yin T, Yang H G, Zhang C, et al. A low-noise readout circuit for MEMS vibratory gyroscope //IEEE Proceedings of Conf on Nano/MicroEngineered and Molecular Systems. 2008:124-1127.
[7] Amini V, Ayazi F. A 2.5V 14bit Σ-Δ CMOS SOI capacitive accelerometer
[J]. IEEE Journal of Solid-State Circuits, 2004, 39(12):2467-2476.
[8] Yazdi N, Mason A, Najafi K, et al. A generic interface chip for capacitive sensors in low-power multi-parameter microsystems
[J]. Sensors and Actuators, 2000, 84: 351-361.
[9] Behzad Razavi. Design of analog CMOS and integrated circuits
[M]. 2002.
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