Biography

Enrollment Date: 2010

Graduation Date：2013

Degree：M.E.

Defense Date：2013.05.28

Advisors：Zhihua Wang

Department：Institute of Microelectronics，Tsinghua University

Title of Dissertation/Thesis：Research on the Low Power Resistance/Capacitance Multi-Sensor System Interface Circuit

Abstract:
With the development of CMOS and MEMS technology, more and more sensors elements are integrated in a multi-sensor system which is used in wireless sensor monitoring system. Different sensors are used to monitor variable physical, chemical and biological signals. These signals are usually converted to electric quantities such as voltage, current, capacitance or inductance, by sensing elements. Then they are further transferred to digital signals so as to be processed in digital circuits. However different electric quantities usually need different conversion circuits. Analog-to-Digital Converter (ADC) is used to convert analog signal, which is amplified by an Instrumentation Amplifier (IA), to digital and Capacitance to Digital Converter (CDC) is designed to convert capacitance to digital output. A CDC here can be implemented by a Capacitance-to-Voltage Converter (CVC) followed by an ADC. But the CVC here consumes more area and power, so this kind of interface circuit may not suitable for wireless sensor monitoring system. In some case, the two convertors can be combined into a single one in a multisensory system to achieve a low power sensor interface. The principle of IA and ADC/CDC is presented. We study kinds of IA and ADC/CDC architectures and choose Indirect Current Feedback Instrumentation Amplifier and Successive Approximation (SAR) ADC/CDC. A Chopping Indirect Current Feedback Instrumentation Amplifier with passive inductor loads is designed in 0.18μm CMOS technology. Post simulation results show that this IA achieves 74nV/√Hz input voltage noise spectrum density flat down to 0.1Hz. The total circuit occupies 0.26mm2 chip area and consumes 25.7A static current from a 2.6V power supply. An ADC combined with CDC is fabricated in 0.18μm CMOS process which adopts SAR topology. Measurement results show that the ENOB of this 11bits converter is 10.15bits and it FoM is 45fJ/conversion-step under 200 kHz sampling. The dynamic power consumption is 9.4μW with 1.4V power supply voltage and the core area is 0.176mm2.

Publications

Papers：：

[1] Ziqiang Wang,Hui Jiang,Chun Zhang,Hanjun Jiang,Zhihua Wang, A chopper current feedback instrument amplifier with bandpass amplification stage, Analog Integrated Circuits and Signal Processing, Vol.81, No.3, pp. 763 - 775, 2014.

[2] Hui Jiang,Ziqiang Wang,Chun Zhang,Hanjun Jiang,Zhihua Wang, A combined low power SAR capacitance-to-digital analog-to-digital converter for multisensory system, Analog Integrated Circuits and Signal Processing, Vol.75, No.2-SI, pp. 311 - 322, 2013.

[3] Hui Jiang,Ziqiang Wang,Liyuan Liu,Chun Zhang,Zhihua Wang, A Combined Low Power SAR Capacitance-to-Digital/Analog-to-Digital Converter for Multisensory System, MWSCAS 2012, pp. 1000 - 1003, 2012.

Patents：

[1] Hui Jiang, Ziqiang Wang, Chun Zhang, Hanjun Jiang, Hong Chen, Zhihua Wang. Method for imbalance correction by controlling amplitude of pre-amplifier: China, 201210569383.5[P]. 2015-09-02.

[2] Hui Jiang, Ziqiang Wang, Chun Zhang, Hanjun Jiang, Hong Chen, Zhihua Wang. Method for imbalance correction by controlling delaying of pre-amplifier: China, 201210569537.0[P]. 2015-08-19.

[3] Hui Jiang, Ziqiang Wang, Chun Zhang, Songping Mai, Hong Chen, Hanjun Jiang, Zhihua Wang. Circuit, measuring device and signal measuring method for reducing chopping amplifier output ripple: China, 201210562798.X[P]. 2015-08-19.