dr. Tan

PhD student
Electronic Instrumentation (EI), Department of Microelectronics

PhD thesis (Jun 2013): Energy-Efficient Capacitive-Sensor Interfaces
Promotor: Michiel Pertijs, Gerard Meijer

Themes: Smart Ultrasound

Projects history

Capacitance-to-Digital Conversion

We have developed a wide variety of energy-efficient capacitance-to-digital converters for the readout of capacitive sensors

  1. A Low-Power Reconfigurable Transceiver ASIC for a CMUT-based Wearable Ultrasound Patch
    Mingliang Tan; Tim Hosman; Jae-Sung An; Zu-Yao Chang; Michiel Pertijs;
    In Annual Workshop on Circuits, Systems and Signal Processing (ProRISC),
    July 2021.

  2. A 64-Channel Transmit Beamformer with ±30V Bipolar High-Voltage Pulsers for Catheter-Based Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; T. Matéo; N. Sénégond; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 55, Issue 7, pp. 1796-1806, July 2020. DOI: 10.1109/JSSC.2020.2987719
    Abstract: ... This article presents a fully integrated 64-channel programmable ultrasound transmit beamformer for catheter-based ultrasound probes, designed to interface with a capacitive micro-machined ultrasound transducer (CMUT) array. The chip is equipped with programmable high-voltage (HV) pulsers that can generate ±30-V return-to-zero (RZ) and non-RZ pulses. The pulsers employ a compact back-to-back isolating HV switch topology that employs HV floating-gate drivers with only one HV MOS transistor each. Further die-size reduction is achieved by using the RZ switches also as the transmit/receive (T/R) needed to pass received echo signals to low-voltage receive circuitry. On-chip digital logic clocked at 200 MHz allows the pulse timing to be programmed with a resolution of 5 ns, while supporting pulses of 1 cycle up to 63 cycles. The chip has been implemented in 0.18-μm HV Bipolar-CMOS-DMOS (BCD) technology and occupies an area of 1.8 mm x 16.5 mm, suitable for integration into an 8-F catheter. Each pulser with embedded T/R switch and digital logic occupies only 0.167 mm². The pulser successfully drives an 18-pF transducer capacitance at pulse frequencies up to 9 MHz. The T/R switch has a measured ON-resistance of ~180 Ω . The acoustic results obtained in combination with a 7.5-MHz 64-element CMUT array demonstrate the ability to generate steered and focused acoustic beams.

  3. A Variable-Gain Low-Noise Transimpedance Amplifier for Miniature Ultrasound Probes
    E. Kang; M. Tan; J. S. An; Z. Y. Chang; P. Vince; N. Sénégond; T. Mateo; C. Meynier; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 55, Issue 12, pp. 3157--3168, December 2020. DOI: 10.1109/jssc.2020.3023618
    Abstract: ... This article presents a low-noise transimpedance amplifier (TIA) designed for miniature ultrasound probes. It provides continuously variable gain to compensate for the time-dependent attenuation of the received echo signal. This time-gain compensation (TGC) compresses the echo-signal dynamic range (DR) while avoiding imaging artifacts associated with discrete gain steps. Embedding the TGC function in the TIA reduces the output DR, saving power compared to prior solutions that apply TGC after the low-noise amplifier. The TIA employs a capacitive ladder feedback network and a current-steering circuit to obtain a linear-in-dB gain range of 37 dB. A variable-gain loop amplifier based on current-reuse stages maintains constant bandwidth in a power-efficient manner. The TIA has been integrated in a 64-channel ultrasound transceiver application-specific integrated circuit (ASIC) in a 180-nm BCDMOS process and occupies a die area of 0.12 mm². It achieves a gain error below ±1 dB and a 1.7 pA/√ Hz noise floor and consumes 5.2 mW from a ±0.9 V supply. B-mode images of a tissue-mimicking phantom are presented that show the benefits of the TGC scheme.

  4. A 2 pA/√Hz Transimpedance Amplifier for Miniature Ultrasound Probes with 36dB Continuous Time-Gain Compensation
    E. Kang; M. Tan; J. An; P. Vince; N. Sénégond; T. Mateo; Cyril Meynier; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 354-355, February 2020.

  5. Energy Consumption Model for Front-End Electronics of Battery-Powered Ultrasound Devices
    M. Tan; M. Pertijs;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    September 2020. abstract.

  6. A 1-D CMUT Transducer with Front-end ASIC in a 9 French Catheter for Intracardiac Echocardiography: Acoustic and Imaging Evaluation
    T. Matéo; P. Vince; N. Sénégond; M. Tan; E. Kang; M. Pertijs;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    September 2020. DOI: 10.1109/IUS46767.2020.9251715
    Abstract: ... In this work, we report the acoustical characterization of a 9 French (Fr) CMUT-based 1D catheter tip (2.5×12.8 mm2 - 64 elements - 7.5 MHz) embedding a 64 channels analog transceiver ASIC (180 nm HV BCD technology) dedicated to Intra-cardiac Echocardiography. To this end, a Through-Silicon-Via process has been integrated in the CMUT process flow to ensure suitable vertical integration level needed to accommodate with the catheter's form factor. Good overall functioning of essential ASIC functionalities with the CMUT, i.e. transmit, beamforming, and receive, is first reported, starting from elementary characterization up to imaging. Additionally, a comparison with a custom discrete solution based on Commercial Off-The-Shelf components (COTS) to provide suitable CMUT preamplification in receive is performed. Using the same CMUT chip either with the ASIC, either with the COTS, allowed to quantify the benefit brought by the ASIC compared to a more straightforward but less integrated solution. Main results highlight that CMUT-on-ASIC allows to recover a much wider bandwidth (BW), increasing by 3 MHz the -6dB upper limit, and therefore getting closer the theoretical BW of the CMUT itself. Moreover, lower element crosstalk is measured on CMUT-on-ASIC device, showing that the ASIC decreases the electrical coupling compared to the COTS. Finally, noise equivalent pressure measurements in comparison with simulations in realistic ICE configuration promise much higher receive sensitivity with the ASIC solution, hence, confirming its great interest for the CMUT technology compared to less integrated solution, especially for catheter application.

  7. An Integrated Programmable High-Voltage Bipolar Pulser with Embedded Transmit/Receive Switch for Miniature Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; N. Sénégond; M. A. P. Pertijs;
    IEEE Solid-State Circuits Letters,
    Volume 2, Issue 9, pp. 79-82, September 2019. DOI: 10.1109/LSSC.2019.2938141
    Abstract: ... This letter presents a compact programmable high-voltage (HV) pulser for ultrasound imaging, designed for driving capacitive micromachined ultrasonic transducers (CMUTs) in miniature ultrasound probes. To enable bipolar return-to-zero (RZ) pulsing and embedded transmit/receive switching, a compact back-to-back isolating HV switch is proposed that employs HV floating-gate drivers with only one HV MOS transistor each. The pulser can be digitally programmed to generate bipolar pulses with and without RZ, with a peak-to-peak swing up to 60 V, as well as negative and positive unipolar pulses. It can generate bursts of up to 63 pulses, with a maximum pulse frequency of 9 MHz for an 18-pF transducer capacitance. Realized in TSMC 0.18um HV BCD technology, the pulser occupies only 0.167mm2 . Electrical characterization results of the pulser, as well as acoustic results obtained in the combination with a 7.5-MHz CMUT transducer, are presented.

  8. A 1.54mW/Element 150μm-Pitch-Matched Receiver ASIC with Element-Level SAR/Shared-Single-Slope Hybrid ADCs for Miniature 3D Ultrasound Probes
    J. Li; Z. Chen; M. Tan; D. van Willigen; C. Chen; Z. Y. Chang; E. Noothout; N. de Jong; M. D. Verweij; M. A. P. Pertijs;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    IEEE, pp. 1-2, June 2019.

  9. An Integrated Programmable High-Voltage Bipolar Pulser with Embedded Transmit/Receive Switch for Miniature Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; N. Sénégond; M. A. P. Pertijs;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    pp. 325--328, October 2019.
    Abstract: ... This paper presents a compact programmable high-voltage (HV) pulser for ultrasound imaging, designed for driving capacitive micro-machined ultrasonic transducers (CMUTs) in miniature ultrasound probes. To enable bipolar return-to-zero pulsing and embedded transmit/receive switching, a compact back-to-back isolating HV switch is proposed that employs HV floating-gate drivers with only one HV MOS transistor each. The pulser can be digitally programmed to generate bipolar pulses with and without return-to-zero, with a peak-to-peak swing up to 60 V, as well as negative and positive unipolar pulses. It can generate bursts of up to 63 pulses, with a maximum pulse frequency of 9 MHz for an 18 pF transducer capacitance. Realized in TSMC 0.18 μm HV BCD technology, the pulser occupies only 0.167 mm2. Electrical characterization results of the pulser, as well as acoustic results obtained in combination with a 7.5-MHz CMUT transducer, are presented.

  10. A Low-Power ASIC with On-Chip Receive Digitization and Bipolar High-Voltage Transmitters for Wearable Ultrasound Devices
    Jae-Sung An; Mingliang Tan; Michiel Pertijs;
    In Annual Workshop on Circuits, Systems and Signal Processing (ProRISC),
    July 2019. poster.

  11. A Front-End ASIC with High-Voltage Transmit Switching and Receive Digitization for 3D Forward-Looking Intravascular Ultrasound Imaging
    M. Tan; C. Chen; Z. Chen; J. Janjic; V. Daeichin; Z. Y. Chang; E. Noothout; G. van Soest; M. D. Verweij; N. de Jong; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 8, pp. 2284-2297, August 2018. DOI: 10.1109/JSSC.2018.2828826
    Abstract: ... This paper presents an area- and power-efficient application-specified integrated circuit (ASIC) for 3-D forward-looking intravascular ultrasound imaging. The ASIC is intended to be mounted at the tip of a catheter, and has a circular active area with a diameter of 1.5 mm on the top of which a 2-D array of piezoelectric transducer elements is integrated. It requires only four micro-coaxial cables to interface 64 receive (RX) elements and 16 transmit (TX) elements with an imaging system. To do so, it routes high-voltage (HV) pulses generated by the system to selected TX elements using compact HV switch circuits, digitizes the resulting echo signal received by a selected RX element locally, and employs an energy-efficient load-modulation datalink to return the digitized echo signal to the system in a robust manner. A multi-functional command line provides the required sampling clock, configuration data, and supply voltage for the HV switches. The ASIC has been realized in a 0.18-μm HV CMOS technology and consumes only 9.1 mW. Electrical measurements show 28-V HV switching and RX digitization with a 16-MHz bandwidth and 53-dB dynamic range. Acoustical measurements demonstrate successful pulse transmission and reception. Finally, a 3-D ultrasound image of a three-needle phantom is generated to demonstrate the imaging capability.

  12. A Pitch-Matched Front-End ASIC with Integrated Subarray Beamforming ADC for Miniature 3-D Ultrasound Probes
    C. Chen; Z. Chen; D. Bera; E. Noothout; Z. Y. Chang; M. Tan; H. Vos; J. Bosch; M. Verweij; N. de Jong; M. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 11, pp. 3050-3064, November 2018. DOI: 10.1109/JSSC.2018.2864295
    Abstract: ... This paper presents a front-end application-specified integrated circuit (ASIC) integrated with a 2-D PZT matrix transducer that enables in-probe digitization with acceptable power dissipation for the next-generation endoscopic and catheter-based 3-D ultrasound imaging systems. To achieve power-efficient massively parallel analog-to-digital conversion (ADC) in a 2-D array, a 10-bit 30 MS/s beamforming ADC that merges the subarray beamforming and digitization functions in the charge domain is proposed. It eliminates the need for costly intermediate buffers, thus significantly reducing both power consumption and silicon area. Self-calibrated charge references are implemented in each subarray to further optimize the system-level power efficiency. High-speed datalinks are employed in combination with the subarray beamforming scheme to realize a 36-fold channel-count reduction and an aggregate output data rate of 6 Gb/s for a prototype receive array of 24 x 6 elements. The ASIC achieves a record power efficiency of 0.91 mW/element during receive. Its functionality has been demonstrated in both electrical and acoustic imaging experiments.

  13. A 2D Ultrasound Transducer with Front-End ASIC and Low Cable Count for 3D Forward-Looking Intravascular Imaging: Performance and Characterization
    J. Janjic; M. Tan; E. Noothout; C. Chen; Z. Chan; Z. Y. Chang; R. H. S. H. Beurskens; G. van Soest; A. F. W. van der Steen; M. D. Verweij; M. A. P. Pertijs; N. de Jong;
    IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control,
    Volume 65, Issue 10, pp. 1832--1844, October 2018. Featured Cover Article. DOI: 10.1109/TUFFC.2018.2859824
    Abstract: ... Intravascular ultrasound is an imaging modality used to visualize atherosclerosis from within the inner lumen of human arteries. Complex lesions like chronic total occlusions require forward-looking intravascular ultrasound (FL-IVUS), instead of the conventional side-looking geometry. Volumetric imaging can be achieved with 2D array transducers, which present major challenges in reducing cable count and device integration. In this work we present an 80-element lead zirconium titanate (PZT) matrix ultrasound transducer for FL-IVUS imaging with a front-end application-specific integrated circuit (ASIC) requiring only 4 cables. After investigating optimal transducer designs we fabricated the matrix transducer consisting of 16 transmit (TX) and 64 receive (RX) elements arranged on top of an ASIC having an outer diameter of 1.5 mm and a central hole of 0.5 mm for a guidewire. We modeled the transducer using finite element analysis and compared the simulation results to the values obtained through acoustic measurements. The TX elements showed uniform behavior with a center frequency of 14 MHz, a -3 dB bandwidth of 44 % and a transmit sensitivity of 0.4 kPa/V at 6 mm. The RX elements showed center frequency and bandwidth similar to the TX elements, with an estimated receive sensitivity of 3.7 μV/Pa. We successfully acquired a 3D FL image of three spherical reflectors in water using delay-and-sum beamforming and the coherence factor method. Full synthetic aperture acquisition can be achieved with frame rates on the order of 100 Hz. The acoustic characterization and the initial imaging results show the potential of the proposed transducer to achieve 3D FL-IVUS imaging.

  14. A 0.91mW/Element Pitch-Matched Front-End ASIC with Integrated Subarray Beamforming ADC for Miniature 3D Ultrasound Probes
    C. Chen; Z. Chen; D. Bera; E. Noothout; Z. Y. Chang; M. Tan; H. J. Vos; J. G. Bosch; M. D. Verweij; N. de Jong; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 186-187, February 2018. DOI: 10.1109/ISSCC.2018.8310246

  15. New Trends in Smart Sensors for Industrial Applications - Part I
    S. Nihtianov; Z. Tan; B. George;
    IEEE Transactions on Industrial Electronics,
    Volume 64, Issue 9, pp. 7281-7283, Sept 2017. DOI: 10.1109/TIE.2017.2725558
    Keywords: ... manufacturing systems;sensors;industrial systems;production equipment;sensor performance;smart sensors;Intelligent sensors;Performance evaluation;Sensor arrays;Sensor phenomena and characterization;Smart devices;Special issues and sections;Wireless sensor networks.

    Abstract: ... In modern industry, productivity, quality, reliability, and safety heavily depend on the performance of the sensors employed. They form an interface between the production equipment and the surrounding environment providing feedback based on the results of the executed operations. Thus, sensors can be found in an extremely wide range of applications in industrial systems, in which they play a very important role. The first element in any control and measurement system is the sensor itself. Sensor performance defines the performance of the control/measurement system and that of the industrial system as a whole. It is not possible to distinguish between correct and incorrect information provided by a sensor, unless additional information provided by another sensor is used. This validates the statement: No machine can perform better than its sensors.

  16. New Trends in Smart Sensors for Industrial Applications - Part II
    S. Nihtianov; Z. Tan; B. George;
    IEEE Transactions on Industrial Electronics,
    Volume 64, Issue 12, pp. 9592-9594, Dec 2017. DOI: 10.1109/TIE.2017.2758038
    Keywords: ... Capacitive sensors;Gas detectors;Intelligent sensors;Magnetic sensors;Special issues and sections;Tactile sensors.

    Abstract: ... This Special Section is dedicated to the latest trends in smart sensors for industrial applications. It has in total 26 papers, published in two parts, each consisting of 13 papers. In the Guest Editorial of Part I, published in the September 2017 issue, we validate the indispensable role sensors have in modern industry. Productivity, quality, reliability, and safety heavily depend on the performance of the sensors employed. This is because sensors form an interface between the production equipment and the surrounding environment and provide feedback based on the results of the executed operations. Consequently, sensors can be found in an extremely wide range of applications in industrial systems. Here, we introduce and briefly summarize the remaining 13 papers from this "Special Section on New Trends in Smart Sensors for Industrial Applications" of the IEEE Transactions on Industrial Electronics .

  17. Advances in Capacitive, Eddy Current, and Magnetic Displacement Sensors and Corresponding Interfaces
    B. George; Z. Tan; S. Nihtianov;
    IEEE Transactions on Industrial Electronics,
    Volume 64, Issue 12, pp. 9595-9607, Dec 2017. DOI: 10.1109/TIE.2017.2726982
    Keywords: ... capacitance measurement;capacitive sensors;displacement measurement;eddy currents;electric current measurement;inductance measurement;inductive sensors;magnetic field measurement;magnetic sensors;position measurement;absolute displacement measurement;absolute displacement sensors;acceleration measurement;capacitive sensors;eddy current sensors;inductive sensor;inertia measurement;magnetic displacement sensors;micrometer scales;nanometer scales;position measurement;pressure measurement;subnanometer scales;vibration measurement;Capacitance;Capacitive sensors;Capacitors;Eddy currents;Electrodes;Magnetic sensors;Capacitive sensors;displacement;eddy current sensors;magnetic sensors.

    Abstract: ... This paper presents a review of the latest advances in the field of capacitive, inductive (eddy current), and magnetic sensors, for measurement of absolute displacement. The need for accurate displacement and position measurement in the micrometer, nanometer, and subnanometer scales has increased significantly over the last few years. Application examples can be found in high-tech industries, metrology, and space equipment. Besides measuring displacement as a primary quantity, absolute displacement sensors are also used when physical quantities such as pressure, acceleration, vibration, inertia, etc., have to be measured. A better understanding of the commonalities between capacitive, inductive, and magnetic displacement sensors, as well as the main performance differences and limitations, will help one make the best choice for a specific application. This review is based on both theoretical analysis and experimental results. The main performance criteria used are: sensitivity, resolution, compactness, long-term stability, thermal drift, and power efficiency.

  18. A Front-End ASIC with High-Voltage Transmit Switching and Receive Digitization for Forward-Looking Intravascular Ultrasound
    M. Tan; C. Chen; Z. Chen; J. Janjic; V. Daeichin; Z. Y. Chang; E. Noothout; G. van Soest; M. Verweij; N. de Jong; M. Pertijs;
    In Proc. IEEE Custom Integrated Circuits Conference (CICC),
    IEEE, pp. 1‒4, April 2017. DOI: 10.1109/cicc.2017.7993708

  19. Forward-Looking IVUS Transducer with Front-End ASIC for 3D Imaging
    J. Janjic; M. Tan; C. Chen; Z. Chen; E. Noothout; Z. Y. Chang; G. van Soest; M. Verweij; A. F. W. van der Steen; M. Pertijs; N. de Jong;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1-1, September 2017. (abstract).
    Abstract: ... Forward-looking intravascular ultrasound (FL-IVUS) transducers are needed to image complex lesions in the coronary arteries, such as chronic total occlusions (CTOs). To achieve 2D and 3D FL-IVUS imaging, transducer arrays can be integrated at the tip of the catheter. However, connecting the elements is challenging due to the limited space available. In this work, we present a FL-IVUS matrix transducer consisting of 16 transmit and 64 receive elements, which are interfaced with an ASIC that requires only 4 micro-coaxial cables. The transducer performance was characterized by hydrophone measurements and FL imaging of three spherical reflectors.

  20. A Front-end ASIC with High-Voltage Transmit Switching and Receive Digitization for Forward-Looking Intra-Vascular Ultrasound
    Mingliang Tan;
    MSc thesis, Delft University of Technology, November 2016.
    document

  21. A method for in-situ measurement of grid impedance and load impedance at 2 k¿150 kHz
    J. Tan; D. Zhao; J.A. Ferreira;
    In HG Kim; DF Tan (Ed.), Proceedings of the 9th International Conference on Power Electronics and ECCE Asia, ICPE-ECCE Asia 2015,
    IEEE, pp. 443-448, 2015. harvest J. Tan afgesloten in metis maar nog wel werkzaam.

  22. Dedicated Impedance-Sensor Systems
    G. Meijer; X. Li; B. Iliev; G. Pop; Z. Y. Chang; S. Nihtianov; Z. Tan; A. Heidari; M. Pertijs;
    In Smart Sensor Systems: Emerging Technologies and Applications,
    John Wiley \& Sons, May 2014.
    Abstract: ... Impedance sensors can be defined as being a set of electrodes which can be used to measure electrical properties of materials or structures. Once these properties are known, it appears that the features of measurements performed with such sensors depend for a large part on the properties of the material or structure to be characterized and only partly on the characteristics of the electrodes. The electrical properties of the sensor in its application can be modeled with passive elements in equivalent electrical circuits. The challenging task for the designer is to make such a sensor system sensitive for the measurands and to obtain immunity for other parameters. In this chapter, we consider impedance sensors to be sensors in a certain measurement environment, and that in the electric model presentation of this setup there is at least one resistive or one reactive component of interest which has to be measured.

    document

  23. A 1.2-V 8.3-nJ CMOS humidity sensor for RFID applications
    Z. Tan; R. Daamen; A. Humbert; Y. V. Ponomarev; Y. Chae; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 48, Issue 10, pp. 2469‒2477, October 2013. DOI: 10.1109/jssc.2013.2275661
    Abstract: ... This paper presents a fully integrated CMOS humidity sensor for a smart RFID sensor platform. The sensing element is a CMOS-compatible capacitive humidity sensor, which consists of top-metal finger-structure electrodes covered by a humidity-sensitive polyimide layer. Its humidity-sensitive capacitance is digitized by an energy-efficient capacitance-to-digital converter (CDC) based on a third-order delta-sigma modulator. This CDC employs current-efficient operational transconductance amplifiers based on current-starved cascoded inverters, whose limited output swing is accommodated by employing a feedforward loop-filter topology. A programmable offset capacitor is included to remove the sensor's baseline capacitance and thus reduce the required dynamic range. To reduce offset errors due to charge injection of the switches, the entire system is auto-zeroed. The proposed humidity sensor has been realized in a 0.16- μm CMOS technology. Measurement results show that the CDC performs a 12.5-bit capacitance-to-digital conversion in a measurement time of 0.8 ms, while consuming only 8.6 μA from a 1.2-V supply. This corresponds to a state-of-the-art figure-of-merit of 1.4 pJ/conversion-step. Combined with the co-integrated humidity sensing element, it provides a resolution of 0.05\% RH in the range from 30\% RH to 100\% RH while consuming only 8.3 nJ per measurement, which is an order-of-magnitude less energy than the state-of-the-art.

  24. A low-power CMOS integrated sensor for CO2 detection in the percentage range
    A. Humbert; B. J. Tuerlings; R. J. O. M. Hoofman; Z. Tan; D. Gravesteijn; M. A. P. Pertijs; C. W. M. Bastiaansen; D. Soccol;
    In Proc. International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS),
    IEEE, pp. 1649‒1652, June 2013. DOI: 10.1109/Transducers.2013.6627101
    Abstract: ... Within the Catrene project “PASTEUR”, a low-cost, low-power capacitive carbon dioxide sensor has been developed for tracking CO2 concentration in the percentage range. This paper describes this sensor, which operates at room temperature where it exhibits short response times as well as reversible behavior. It can be easily integrated using CMOS compatible processing, and has been combined with a Relative Humidity (RH) sensor, using the same capacitive transduction method, and with a low-power capacitance-to-digital converter, hence enabling correction of cross sensitivity to RH.

  25. A 1V 14b self-timed zero-crossing-based incremental ΔΣ ADC
    C. Chen; Z. Tan; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 274‒275, February 2013. DOI: 10.1109/ISSCC.2013.6487732
    Abstract: ... This paper introduces a clock-free self-timed incremental ΔΣ ADC. Unlike conventional ΔΣ ADCs, it does not require a dedicated clock signal, thus saving energy and reducing system complexity. As such, it has similar advantages as self-timed (or asynchronous) SAR ADCs. It is particularly suited for use in energy-constrained sensor applications, in which conversions of a quasistatic input signal are triggered by infrequent and possibly irregular external events. As it autonomously powers down upon completion of a conversion, it can adapt to a wide range of conversion rates in an energy-efficient way.

  26. Ultra-low Energy CMOS Humidity Sensors for RFID Applications
    Z. Tan; R. Daamen; A. Humbert; Y. V. Ponomarev; Y. Chae; G. C. M. Meijer; M. A. P. Pertijs;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, April 2013. (Best Poster Award).

  27. Energy-efficient capacitive-sensor interfaces
    Z. Tan;
    PhD thesis, Delft University of Technology, 2013. Harvest.

  28. 4T CMOS active pixel sensors under ionizing radiation
    J. Tan;
    PhD thesis, Delft University of Technology, 2013. Harvest.

  29. Energy-Efficient Capacitive Sensor Interfaces
    Zhichao Tan;
    PhD thesis, Delft University of Technology, June 2013.
    document

  30. Analyzing the radiation degradation of 4-transistor deep submicron technology CMOS image sensors
    J. Tan; B. Buttgen; A.J.P. Theuwissen;
    IEEE Sensors Journal,
    Volume 12, Issue 6, pp. 2278-2286, 2012. Harvest Article number: 6143978.

  31. An energy-efficient 15-bit capacitive-sensor interface based on period modulation
    Z. Tan; S. H. Shalmany; G. C. M. Meijer; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 47, Issue 7, pp. 1703‒1711, July 2012. DOI: 10.1109/jssc.2012.2191212
    Abstract: ... This paper presents an energy-efficient capacitive-sensor interface with a period-modulated output signal. This interface converts the sensor capacitance to a time interval, which can be easily digitized by a simple digital counter. It is based on a relaxation oscillator consisting of an integrator and a comparator. To enable the use of a current-efficient telescopic OTA in the integrator, negative feedback loops are applied to limit the integrator's output swing. To obtain an accurate ratiometric output signal, auto-calibration is applied. This eliminates errors due to comparator delay, thus enabling the use of a low-power comparator. Based on an analysis of the stability of the negative feedback loops, it is shown how the current consumption of the interface can be traded for its ability to handle parasitic capacitors. A prototype fabricated in 0.35 μm standard CMOS technology can handle parasitic capacitors up to five times larger than the sensor capacitance. Experimental results show that it achieves 15-bit resolution and 12-bit linearity within a measurement time of 7.6 ms for sensor capacitances up to 6.8 pF, while consuming only 64 μA from a 3.3 V power supply. Compared to prior work with similar performance, this represents a significant improvement in energy efficiency.

  32. Energy-Efficient Capacitive Sensor Interfaces
    M. A. P. Pertijs; Z. Tan;
    In Nyquist AD Converters, Sensor Interfaces, and Robustness,
    Springer Science \& Business Media, October 2012.
    Abstract: ... Capacitive sensor systems are potentially highly energy efficient. In practice, however, their energy consumption is typically dominated by that of the interface circuit that digitizes the sensor capacitance. Energy-efficient capacitive sensor interfaces are therefore a prerequisite for the successful application of capacitive sensors in energy-constrained applications, such as battery-powered devices and wireless sensor nodes. This paper derives lower bounds on the energy consumption of capacitive sensor interfaces. A comparison of these bounds with the state-of-the-art suggests that there is significant room for improvement. Several approaches to improving energy efficiency are discussed and illustrated by two design examples.

    document

  33. A 1.2 V 8.3 nJ energy-efficient CMOS humidity sensor for RFID applications
    Z. Tan; Y. Chae; R. Daamen; A. Humbert; Y. V. Ponomarev; M. A. P. Pertijs;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    IEEE, pp. 24‒25, June 2012. DOI: 10.1109/vlsic.2012.6243771

  34. Energy-Efficient Capacitive Sensor Interfaces
    M. Pertijs; Z. Tan;
    In Proc. Workshop on Advances in Analog Circuit Design (AACD),
    March 2012. invited paper. DOI: 10.1007/978-1-4614-4587-6_8

  35. 4T CMOS Image Sensor Pixel Degradation due to X-ray Radiation
    J. Tan; B. Buettgen; A.J.P. Theuwissen;
    In N Terashini; J Nakamura (Ed.), 2011 International Image Sensor Workshop - IISW,
    Image Sensors, pp. 228-231, 2011.

  36. X-ray radiation effect on CMOS imagers with in-pixel buried-channel source follower
    Y. Chen; J. Tan; X. Wang; A.J. Mierop; A.J.P. Theuwissen;
    In H Tenhunen; M Aberg (Ed.), 41st IEEE European Solid-State Device Research Conference (ESSDERC) 2011,
    IEEE, pp. 155-158, 2011.

  37. A 1.8V 11μW CMOS smart humidity sensor for RFID sensing applications
    Z. Tan; R. Daamen; A. Humbert; K. Souri; Y. Chae; Y. V. Ponomarev; M. A. P. Pertijs;
    In Proc. IEEE Asian Solid State Circuits Conference (A-SSCC),
    IEEE, pp. 105‒108, November 2011. DOI: 10.1109/ASSCC.2011.6123615
    Abstract: ... A fully-integrated humidity sensor for a smart RFID sensor platform has been realized in 0.16μm standard CMOS technology. It consists of a top-metal finger-structure capacitor covered with a humidity-sensitive layer, combined with a micro-power flexible sensor interface based on a second-order incremental delta-sigma converter. The interface can be easily reconfigured to compensate for process variation of the sensing element. In a measurement time of 10.2 ms, the interface performs a 13-bits capacitance-to-digital conversion while consuming only 5.85 μA from 1.8 V supply. In combination with the co-integrated sensor capacitor, it thus provides a humidity-to-digital conversion with a resolution of 0.1\% RH in the range of 20\% to 90\% RH at only 107 nJ per measurement. This represents a significant improvement in energy efficiency compared to existing capacitive-sensor interfaces with comparable performance.

  38. An energy-efficient 15-bit capacitive sensor interface
    Z. Tan; M. A. P. Pertijs; G. Meijer;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 283‒286, September 2011. DOI: 10.1109/esscirc.2011.6044962

  39. X-ray radiation effects on CMOS image sensor in-pixel devices
    J. Tan; B. Buttgen; A.J.P. Theuwissen;
    In s.n. (Ed.), Proceedings of International conference on solid-state devices and materials 2010,
    pp. 299-300, 2010.

  40. In-pixel buried-channel source follower in CMOS image sensors exposed to X-ray radiation
    C. Yue; J. Tan; X. Wang; A. Mierop; A.J.P. Theuwissen;
    In s.n. (Ed.), Proceedings of IEEE sensors 2010,
    IEEE, pp. 1649-1652, 2010.

  41. Total ionizing effects on 4-transistor CMOS image sensor pixels
    J. Tan; A.J.P. Theuwissen;
    In JB Xu; PKT Mok (Ed.), Proceedings of IEEE International conference on Electron Devices and Solid-State Circuits (EDSSC'10),
    IEEE, pp. 1-4, 2010.

  42. Radiation effects on CMOS image sensors due to X-rays
    J. Tan; B. Buttgen; A.J.P. Theuwissen;
    In J Breza; D Donoval; E Vavrinsky (Ed.), Proceedings 8th International conference on Advanced Semiconductor Devices and Microsystems (ASDAM),
    IEEE, pp. 279-283, 2010.

  43. Energy-efficient capacitive sensor interface with high dynamic range
    Z. Tan; M. A. P. Pertijs; G. C. M. Meijer;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, April 2010.

  44. A low power universal capacitive sensor interface for autonomous sensor applications
    Z. Tan; G.C.M. Meijer;
    s.n. (Ed.);
    Sense of Contact 2009, , pp. 1-4, 2009.

  45. Reliability analysis of single grain Si TFT using 2D simulation
    A. Baiano; J. Tan; R. Ishihara; C.I.M. Beenakker;
    In Y Kuo (Ed.), Thin film transistors 9 (TFT 9),
    s.n., pp. 109-114, 2008.

  46. 2D simulation of hot-carrier-induced degradation and reliability analysis for single grain Si TFTs
    J. Tan; A. Baiano; R. Ishihara; C.I.M. Beenakker;
    In s.n. (Ed.), The annual workshop on semiconductor advances for future electronics and sensors,
    STW, pp. 600-603, 2008.

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Last updated: 26 Dec 2018

Zhichao Tan

Alumnus
  • Left in 2013