Michiel Pertijs

Publications

  1. A CMOS Readout Circuit for Resistive Transducers Based on Algorithmic Resistance and Power Measurement
    Z. Cai; L. Rueda Guerrero; A. Louwerse; H. Suy; R. van Veldhoven; K. Makinwa; M. Pertijs;
    IEEE Sensors Journal,
    2017. in press.

  2. A Precision Capacitance-to-Digital Converter with 16.7-bit ENOB and 7.5 ppm/°C Thermal Drift
    R. Yang; M. A. P. Pertijs; S. Nihtianov;
    IEEE Journal of Solid-State Circuits,
    Volume 52, Issue 11, pp. 3018-3031, November 2017. DOI: 10.1109/jssc.2017.2734900
    Abstract: ...
    This paper presents a high-precision capacitance-to-digital converter (CDC) for displacement measurement in advanced industrial applications, based on a charge-balancing third-order delta–sigma modulator. To achieve high precision, this CDC employs a precision external resistive reference and a quartz-oscillator-based time reference instead of a reference capacitor. To minimize the error contribution of the CDC circuitry, various precision circuit techniques, such as chopping and auto-zeroing, are applied at both system and circuit level. Measurement results of the prototype realized in 0.35-μm CMOS technology show that the CDC achieves an rms resolution of 42 aF across a capacitance range from 6 to 22 pF, corresponding to an effective number of bits (ENOB) of 16.7 bit. The conversion time for one measurement is 10.5 ms, during which the CDC consumes 230 μA from a 3.3-V single supply. The measured thermal stability is within ±7.5 ppm/°C across a temperature range from 20 °C to 70 °C, which represents a significant improvement compared to the state of the art. After a two-point calibration, all ten measured samples from one batch show absolute accuracy below ±25 fF across the entire capacitance measurement range.

  3. A 40-nm CMOS Complex Permittivity Sensing Pixel for Material Characterization at Microwave Frequencies
    G. Vlachogiannakis; M. A. P. Pertijs; M. Spirito; L. C. N. de Vreede;
    IEEE Transactions on Microwave Theory and Techniques,
    2017. in press. DOI: 10.1109/tmtt.2017.2753228
    Abstract: ...
    A compact sensing pixel for the determination of the localized complex permittivity at microwave frequencies is proposed. Implemented in the 40-nm CMOS, the architecture comprises a square patch, interfaced to the material-under-test sample, that provides permittivity-dependent admittance. The patch admittance is read out by embedding the patch in a double-balanced, RF-driven Wheatstone bridge. The bridge is cascaded by a linear, low-intermediate frequency switching downconversion mixer, and is driven by a square wave that allows simultaneous characterization of multiple harmonics, thus increasing measurement speed and extending the frequency range of operation. In order to allow complex permittivity measurement, a calibration procedure has been developed for the sensor. Measurement results of liquids show good agreement with theoretical values, and the measured relative permittivity resolution is better than 0.3 over a 0.1-10-GHz range. The proposed implementation features a measurement speed of 1 ms and occupies an active area of 0.15x0.3 mm², allowing for future compact arrays of multiple sensors that facilitate 2-D dielectric imaging based on permittivity contrast.

  4. A 7μW Offset-and Temperature-Compensated pH-to-Digital Converter
    S. H. Shalmany; M. Merz; A. Fekri; Z. Y. Chang; R. J. O. M. Hoofman; M. A. P. Pertijs;
    Journal of Sensors,
    Volume 2017, Issue 6158689, January 2017. DOI: 10.1155/2017/6158689
    Abstract: ...
    This paper demonstrates a micropower offset- and temperature-compensated smart pH sensor, intended for use in battery-powered RFID systems that monitor the quality of perishable products. Low operation power is essential in such systems to enable autonomous logging of environmental parameters, such as the pH level, over extended periods of time using only a small, low-cost battery. The pH-sensing element in this work is an ion-sensitive extended-gate field-effect transistor (EGFET), which is incorporated in a low-power sensor front-end. The front-end outputs a pH-dependent voltage, which is then digitized by means of a co-integrated incremental delta-sigma ADC. To compensate for the offset and temperature cross-sensitivity of the EGFET, a compensation scheme using a calibration process and a temperature sensor has been devised. A prototype chip has been realized in a 0.16 μm CMOS process. It occupies 0.35 × 3.9 mm2 of die area and draws only 4 μA from a 1.8 V supply. Two different types of custom packaging have been used for measurement purposes. The pH sensor achieves a linearity of better than ±0.1 for pH values ranging from 4 to 10. The calibration and compensation scheme reduces errors due to temperature cross-sensitivity to less than ±0.1 in the temperature range of 6°C to 25°C.

  5. A Front-end ASIC with Receive Sub-Array Beamforming Integrated with a 32 × 32 PZT Matrix Transducer for 3-D Transesophageal Echocardiography
    C. Chen; Z. Chen; D. Bera; S. B. Raghunathan; M. Shabanimotlagh; E. Noothout; Z. Y. Chang; J. Ponte; C. Prins; H. J. Vos; J.G. Bosch; M.D. Verweij; N. de Jong; M.A.P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 52, Issue 4, pp. 994‒1006, April 2017. DOI: 10.1109/JSSC.2016.2638433
    Abstract: ...
    This paper presents a power- and area-efficient front-end application-specific integrated circuit (ASIC) that is directly integrated with an array of 32 × 32 piezoelectric transducer elements to enable next-generation miniature ultrasound probes for real-time 3-D transesophageal echocardiography. The 6.1 × 6.1 mm2 ASIC, implemented in a low-voltage 0.18-μm CMOS process, effectively reduces the number of receive (RX) cables required in the probe's narrow shaft by ninefold with the aid of 96 delay-and-sum beamformers, each of which locally combines the signals received by a sub-array of 3 × 3 elements. These beamformers are based on pipeline-operated analog sample-and-hold stages and employ a mismatch-scrambling technique to prevent the ripple signal associated with the mismatch between these stages from limiting the dynamic range. In addition, an ultralow-power low-noise amplifier architecture is proposed to increase the power efficiency of the RX circuitry. The ASIC has a compact element matched layout and consumes only 0.27 mW/channel while receiving, which is lower than the state-of-the-art circuit. Its functionality has been successfully demonstrated in 3-D imaging experiments.

  6. A Reconfigurable 24 × 40 Element Transceiver ASIC for Compact 3D Medical Ultrasound Probes
    E. Kang; Q. Ding; M. Shabanimotlagh; P. Kruizinga; Z.Y. Chang; E. Noothout; H.J. Vos; J.G. Bosch; M.D. Verweij; N. de Jong; M.A.P. Pertijs;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 211-214, September 2017.

  7. Volumetric imaging using adult matrix TEE with separated transmit and receive array
    D. Bera; F. van den Adel; N. Radeljic-Jakic; B. Lippe; M. Soozande; M. Pertijs; M. Verweij; P. Kruizinga; V. Daeichin; H. Vos; J. Bosch; N. de Jong;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1-1, September 2017. abstract.

  8. Towards 3D ultrasound imaging of the carotid artery using a programmable and tileable matrix array
    P. Kruizinga; E. Kang; M. Shabanimotlagh; Q. Ding; E. Noothout; Z. Y. Chang; H. J. Vos; J. G. Bosch; M. D. Verweij; M. A. P. Pertijs; N. de Jong;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1-3, September 2017.

  9. The Directivity of Piezoelectric Matrix Transducer Elements Mounted on an ASIC
    M. Shabanimotlagh; S. Raghunathan; V. Daeichin; P. Kruizinga; H. J. Vos; M. A. P. Pertijs; J. G. Bosch; N. de Jong; M. D. Verweij;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1-4, September 2017.

  10. A Fresnel-inspired approach for steering and focusing a pulsed transmit beam with matrix array transducers
    M. Verweij; M. Pertijs; J. de Wit; F. Fool; H. Vos; N. de Jong;
    In The Journal of the Acoustical Society of America,
    June 2017. DOI: 10.1121/1.4987739
    Abstract: ...
    Matrix ultrasound transducers for medical diagnostic purposes are commercially available for a decade. A typical matrix transducer contains 1000 + elements, with a trend towards more and smaller elements. This number renders direct connection of each individual element to an ultrasound machine impractical. Consequently, it is cumbersome to employ traditional focusing and beamforming approaches that are based on transmit and receive signals having an individual time delay for each element. To reduce cable count during receive, one approach is to apply sub-arrays that locally combine the element signals using programmable delay-and-sum hardware, resulting in reduction by a factor 10. In transmit, achieving cable count reduction while keeping focusing and steering capabilities turns problematic once it becomes impossible to locally equip each element with its own high voltage pulser. To overcome this bottleneck for decreasing element size, here we present a Fresnel-inspired hardware and beam forming approach that is based on transmit pulses consisting of several periods of an oscillating waveform. These will be derived from one oscillating high voltage signal by using local switching and timing hardware. To demonstrate the feasibilities of our approach, we will show beam profiles and images for a miniature matrix transducer that we are currently developing.

  11. A compact sensor readout circuit with temperature, capacitance and voltage sensing functionalities
    B. Yousefzadeh; W. Wu; B. Buter; K. Makinwa; M. Pertijs;
    In NXP Low-Power Design Conference,
    NXP, June 2017. (submitted).
    Abstract: ...
    This paper presents an area- and energy-efficient sensor readout circuit, which can precisely digitize temperature, capacitance and voltage. The three modes use only on-chip references and employ a shared zoom ADC based on SAR and ΔΣ conversion to save die area. Measurements on 24 samples from a single wafer show a temperature inaccuracy of ±0.2 °C (3σ) over the military temperature range (-55°C to 125°C). The voltage sensing shows an inaccuracy of ±0.5\%. The sensor also offers 18.7-ENOB capacitance-to-digital conversion, which handles up to 3.8 pF capacitance with a 0.76 pJ/conv.-step energy-efficiency FoM. It occupies 0.33 mm² in a 0.16 μm CMOS process and draws 4.6 μA current from a 1.8 V supply.

  12. A Compact Sensor Readout Circuit with Combined Temperature, Capacitance and Voltage Sensing Functionality
    B. Yousefzadeh; W. Wu; B. Buter; K.A.A. Makinwa; M. Pertijs;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    IEEE, pp. 1‒2, June 2017. DOI: 10.23919/VLSIC.2017.8008555
    Abstract: ...
    This paper presents an area- and energy-efficient sensor readout circuit, which can precisely digitize temperature, capacitance and voltage. The three modes use only on-chip references and employ a shared zoom ADC based on SAR and ΔΣ conversion to save die area. Measurements on 24 samples from a single wafer show a temperature inaccuracy of ±0.2 °C (3σ) over the military temperature range (-55°C to 125°C). The voltage sensing shows an inaccuracy of ±0.5\%. The sensor also offers 18.7-ENOB capacitance-to-digital conversion, which handles up to 3.8 pF capacitance with a 0.76 pJ/conv.-step energy-efficiency FoM. It occupies 0.33 mm² in a 0.16 μm CMOS process and draws 4.6 μA current from a 1.8 V supply.

  13. Acoustic Characterization of a 32 × 32 Element PZT-on-ASIC Matrix Transducer for 3D Transesophageal Echocardiography
    M. Shabanimotlagh; S. Raghunathan; D. Bera; Z. Chen; C. Chen; V. Daeichin; M. Pertijs; J.G. Bosch; N. de Jong; M. Verweij;
    In Dutch Bio-Medical Engineering Conference,
    The Netherlands, 2017. (accepted).

  14. An Element-Matched Band-Pass Delta-Sigma ADC for Ultrasound Imaging
    M. D’Urbino; C. Chen; Z. Chen; Z. Y. Chang; J. Ponte; B. Lippe; M. Pertijs;
    In Proc. IEEE Asian Solid State Circuits Conference (A-SSCC),
    IEEE, November 2017. Accepted for presentation.

  15. A Front-End ASIC for Miniature 3-D Ultrasound Probes with In-Probe Receive Digitization
    C. Chen; Z. Chen; D. Bera; E. Noothout; Z.Y. Chang; H. Vos; J. Bosch; M. Verweij; N. de Jong; M. Pertijs;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1-4, September 2017. Winner Best Student Paper Competition.

  16. 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.

  17. 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

  18. A Ratiometric Readout Circuit for Thermal-Conductivity-Based Resistive CO$_2$ Sensors
    Z. Cai; R. H. M. van Veldhoven; A. Falepin; H. Suy; E. Sterckx; C. Bitterlich; K. A. A. Makinwa; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 51, Issue 10, pp. 2453‒2474, October 2016. DOI: 10.1109/jssc.2016.2587861
    Abstract: ...
    This paper reports a readout circuit for a resistive CO2 sensor, which operates by measuring the CO2-dependent thermal conductivity of air. A suspended hot-wire transducer, which acts both as a resistive heater and temperature sensor, exhibits a CO2-dependent heat loss to the surrounding air, allowing CO2 concentration to be derived from its temperature rise and power dissipation. The circuit employs a dual-mode incremental delta-sigma ADC to digitize these parameters relative to those of an identical, but isolated, reference transducer. This ratiometric approach results in a measurement that does not require precision voltage or power references. The readout circuit uses dynamically-swapped transducer pairs to cancel their baseline-resistance, so as to relax the required dynamic range of the ADC. In addition, dynamic element matching (DEM) is used to bias the transducer pairs at an accurate current ratio, making the measurement insensitive to the precise value of the bias current. The readout circuit has been implemented in a standard 0.16 μm CMOS technology. With commercial resistive micro-heaters, a CO2 sensing resolution of about 200 ppm (1σ) was achieved in a measurement time of 30 s. Similar results were obtained with CMOS-compatible tungsten-wire transducers, paving the way for fully-integrated CO2 sensors for air-quality monitoring.

  19. A 30-ppm <80 nJ Ring-Down-Based Readout Circuit for Resonant Sensors
    H. Jiang; Z. Y. Chang; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 51, Issue 1, pp. 187‒195, January 2016. DOI: 10.1109/JSSC.2015.2470552
    Abstract: ...
    This paper presents an energy-efficient readout circuit for micro-machined resonant sensors. It operates by briefly exciting the sensor at a frequency close to its resonance frequency, after which resonance frequency and quality factor are determined from a single ring-down transient. The circuit employs an inverter-based trans-impedance amplifier to sense the ring-down current, with a programmable feedback network to enable the readout of different resonant sensors. An inverter-based comparator with dynamically-adjusted threshold levels tracks the ring-down envelope to measure quality factor, and detects zero crossings to measure resonance frequency. The excitation frequency is dynamically adjusted to accommodate large resonance frequency shifts. Experimental results obtained with a prototype fabricated in 0.35 μm standard CMOS technology and three different SiN resonators are in good agreement with conventional impedance analysis. The prototype achieves a frequency resolution better than 30 ppm while consuming less than 80 nJ/meas from a 1.8 V supply, which is 7.8x less than the state-of-the-art.

  20. A Prototype PZT Matrix Transducer with Low-Power Integrated Receive ASIC for 3D Transesophageal Echocardiography.
    C. Chen; S. Raghunathan; Z. Yu; M. Shabanimotlag; Z. Chen; Z. Y. Chang; S. Blaak; C. Prins; J. Ponte; E. Noothout; H. J. Vos; J. G. Bosch; M. D. Verweij; N. de Jong; M. A. P. Pertijs;
    IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control,
    Volume 63, Issue 1, pp. 47‒59, January 2016. DOI: 10.1109/tuffc.2015.2496580
    Abstract: ...
    This paper presents the design, fabrication, and experimental evaluation of a prototype lead zirconium titanate (PZT) matrix transducer with an integrated receive ASIC, as a proof of concept for a miniature three-dimensional (3-D) transesophageal echocardiography (TEE) probe. It consists of an array of 9 × 12 piezoelectric elements mounted on the ASIC via an integration scheme that involves direct electrical connections between a bond-pad array on the ASIC and the transducer elements. The ASIC addresses the critical challenge of reducing cable count, and includes front-end amplifiers with adjustable gains and microbeamformer circuits that locally process and combine echo signals received by the elements of each 3 × 3 subarray. Thus, an order-of-magnitude reduction in the number of receive channels is achieved. Dedicated circuit techniques are employed to meet the strict space and power constraints of TEE probes. The ASIC has been fabricated in a standard 0.18-μm CMOS process and consumes only 0.44 mW/channel. The prototype has been acoustically characterized in a water tank. The ASIC allows the array to be presteered across ±37° while achieving an overall dynamic range of 77 dB. Both the measured characteristics of the individual transducer elements and the performance of the ASIC are in good agreement with expectations, demonstrating the effectiveness of the proposed techniques.

  21. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging
    V. Daeichin; C. Chen; Q. Ding; M. Wu; R. Beurskens; G. Springeling; E. Noothout; M. D. Verweij; K. W. A. van Dongen; J. G. Bosch; A. F. W van der Steen; N. de Jong; M. Pertijs; G. van Soest;
    Ultrasound in Medicine \& Biology,
    Volume 42, Issue 5, pp. 1239‒1243, May 2016. DOI: 10.1016/j.ultrasmedbio.2015.12.016
    Abstract: ...
    Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm2) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1–20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz.

  22. An Integrated Carbon Dioxide Sensor for Air-Quality Monitoring
    Z. Cai; R.H.M. van Veldhoven; A. Falepin; H. Suy; E. Sterckx; C. Bitterlich; K.A.A. Makinwa; M.A.P. Pertijs;
    In Proc. Conference for ICT-Research in the Netherlands (ICT.OPEN),
    The Netherlands, March 2016.

  23. The role of sub-dicing in the acoustical design of an ultrasound matrix transducer for carotid arteries imaging
    M. Shabanimotlagh; J. Janjic; S. Raghunathan; M. A. P. Pertijs; N. de Jong; M. Verweij;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1‒4, September 2016. DOI: 10.1109/ultsym.2016.7728470

  24. A 40-nm CMOS permittivity sensor for chemical/biological material characterization at RF/microwave frequencies
    G. Vlachogiannakis; M. Spirito; M. A. P. Pertijs; L. C. N. de Vreede;
    In Proc. IEEE MTT-S International Microwave Symposium (IMS),
    IEEE, pp. 1‒4, May 2016. DOI: 10.1109/mwsym.2016.7540260

  25. A broadband PVDF-based hydrophone with integrated readout circuit for intravascular photoacoustic imaging
    V. Daeichin; C. Chen; Q. Ding; M. Wu; R. Beurskens; G. Springeling; E. Noothout; M. D. Verweij; K. W.A. van Dongen; J. G. Bosch; A. F. W van der Steen; N. de Jong; M. Pertijs; G. van Soest;
    In Proc. SPIE Photonics West,
    SPIE, February 2016. DOI: 10.1016/j.ultrasmedbio.2015.12.016
    Abstract: ...
    Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm2) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1–20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz.

  26. A front-end ASIC with receive sub-array beamforming integrated with a 32 × 32 PZT matrix transducer for 3-D transesophageal echocardiography
    C. Chen; Z. Chen; D. Bera; S. B. Raghunathan; M. Shabanimotlagh; E. Noothout; Z. Y. Chang; J. Ponte; C. Prins; H. J. Vos; J.G. Bosch; M.D. Verweij; N. de Jong; M.A.P. Pertijs;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    IEEE, pp. 1‒2, September 2016. DOI: 10.1109/vlsic.2016.7573470

  27. Acoustic Characterisation of a 32 × 32 Element PZT-on-CMOS Matrix Transducer for 3D TEE
    S. Raghunathan; D. Bera; C. Chen; Z. Chen; M. Shabanimotlagh; E. Noothout; Z.Y. Chang; H. Vos; C. Prins; J. Ponte; J. Bosch; M. Pertijs; N. de Jong; M. Verweij;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    September 2016.

  28. Three-dimensional beamforming combining micro-beamformed RF datasets
    D. Bera; H. J. Vos; S. B. Raghunathan; C. Chen; Z. Chen; M. D. Verweij; M. A. P. Pertijs; N. de Jong; J. G. Bosch;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1‒4, September 2016. DOI: 10.1109/ultsym.2016.7728449

  29. RATIOMETRIC DEVICE
    Z. Cai; M. A. P. Pertijs; R. H. M. van Veldhoven; K. A. A. Makinwa;
    Patent, United States 2016/0109396, April~21 2016.

  30. A ratiometric readout circuit for thermal-conductivity-based resistive gas sensors
    Z. Cai; R. H. M. van Veldhoven; A. Falepin; H. Suy; E. Sterckx; K. A. A. Makinwa; M. A. P. Pertijs;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 275‒278, September 2015. DOI: 10.1109/esscirc.2015.7313880

  31. Low Power Receive Electronics for a Miniature Real-Time 3D Ultrasound Probe
    Z. Chen; C. Chen; S. B. Raghunathan; D. Bera; Z. Chang; S. Blaak; C. Prins; J. Ponte; J.G. Bosch; N. de Jong; M. D. Verweij; M.A.P. Pertijs;
    In Proc. Conference for ICT-Research in the Netherlands (ICT.OPEN),
    The Netherlands, March 2015.

  32. An integrated carbon dioxide sensor based on ratiometric thermal-conductivity measurement
    Z. Cai; van R. H. M. Veldhoven; A. Falepin; H. Suy; E. Sterckx; K. A. A. Makinwa; M. A. P. Pertijs;
    In Proc. International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS),
    IEEE, pp. 622‒625, June 2015. DOI: 10.1109/transducers.2015.7181000

  33. A generic read-out circuit for resistive transducers
    B. Yousefzadeh; U. Sonmez; N. Mehta; J. Borremans; M. A. P. Pertijs; K. A. A. Makinwa;
    In Proc. IEEE International Workshop on Advances in Sensors and Interfaces (IWASI),
    IEEE, pp. 122‒125, June 2015. DOI: 10.1109/iwasi.2015.7184929

  34. A 30ppm <80nJ ring-down-based readout circuit for resonant sensors
    H. Jiang; Z. Y. Chang; M. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 482‒483, February 2015. DOI: 10.1109/ISSCC.2015.7063136
    Abstract: ...
    A readout circuit for MEMS resonant sensors, realized in 0.35μm CMOS, employs a dynamically-switching level-crossing detector to determine resonance frequency and quality factor from a single ring-down transient. Results obtained with three different resonators are in good agreement conventional impedance analysis. The circuit achieves a frequency resolution better than 30 ppm while consuming less than 80 nJ/meas from a 1.8V supply, 7.8x less than the state-of-the-art.

  35. A 0.05mm² 1V capacitance-to-digital converter based on period modulation
    Y. He; Z. Y. Chang; L. Pakula; S. H. Shalmany; M. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 486‒487, February 2015. DOI: 10.1109/ISSCC.2015.7063138
    Abstract: ...
    This paper presents a digitally assisted period modulation (PM)-based capacitance-to-digital converter (CDC) that is >9× smaller than prior CDCs with >10b resolution, and improves the energy efficiency by >10× compared to previous PM-based CDCs. This is achieved with the help of a piece-wise charge transfer technique that eliminates the need for a large on-chip integration capacitor, a dual-integration-capacitor scheme that reduces the front-end noise contribution, a sampled-biasing technique that reduces the noise of the integration current, and a current-efficient inverter-based design.

  36. Low-power receive electronics for a miniature real-time 3D ultrasound probe
    M. Pertijs; C. Chen; S. Raghunathan; Z. Yu; M. ShabaniMotlagh; Z. Chen; Z. Y. Chang; E. Noothout; S. Blaak; J. Ponte; C. Prins; H. Bosch; M. Verweij; N. de Jong;
    In Proc. IEEE International Workshop on Advances in Sensors and Interfaces (IWASI),
    IEEE, pp. 235‒238, June 2015. (invited paper). DOI: 10.1109/iwasi.2015.7184963

  37. A compact 0.135-mW/channel LNA array for piezoelectric ultrasound transducers
    C. Chen; Z. Chen; Z. Y. Chang; M. A. P. Pertijs;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 404‒407, September 2015. DOI: 10.1109/esscirc.2015.7313913

  38. A single-cable PVDF transducer readout IC for intravascular photoacoustic imaging
    C. Chen; V. Daeichin; Q. Ding; G. van Soest; G. Springeling; T. van der Steen; M. Pertijs; N. de Jong;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1‒4, October 2015. DOI: 10.1109/ultsym.2015.0142

  39. Acoustic Characterisation of a PZT Matrix With Integrated Electronics for a 3D-TEE Probe
    S. Raghunathan; C. Chen; M. Shabanimotlagh; Z. Chen; S. Blaak; Z. Yu; C. Prins; M. Pertijs; J. Bosch; N. de Jong; M. Verweij;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    October 2015.

  40. A mixed-signal multiplexing system for cable-count reduction in ultrasound probes
    Q. Liu; C. Chen; Z. Y. Chang; C. Prins; M. A. P. Pertijs;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 1‒4, October 2015. DOI: 10.1109/ultsym.2015.0141

  41. Temperature sensor for a leadless cardiac pacemaker
    M. A. P. Pertijs; K. J. Carroll;
    Patent, United States 9,060,692, June~23 2015.

  42. Highlights of the ISSCC 2013 Processors and High Performance Digital Sessions
    T. Fischer; B. G. Nam; L. Chang; T. Kuroda; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 49, Issue 1, pp. 4‒8, 2014. DOI: 10.1109/jssc.2013.2284658
    Abstract: ...
    This special issue covers the ISSCC conference held in San Francisco, CA, USA, on February 17-21, 2013. The issue includes the topics from the low power and high performance digital, memory, and technology directions as well as imagers, medical and sensors. There are 27 papers in the issue.

  43. Smart sensor systems: Emerging technologies and applications
    G. Meijer; K. Makinwa; M. Pertijs;
    John Wiley \& Sons, , 2014.
    Abstract: ...
    With contributions from an internationally-renowned group of experts, this book uses a multidisciplinary approach to review recent developments in the field of smart sensor systems, covering important system and design aspects. It examines topics over the whole range of sensor technology from the theory and constraints of basic elements, physics and electronics, up to the level of application-orientated issues.

    document

  44. Calibration and Self-Calibration of Smart Sensors
    M. Pertijs;
    G. Meijer; K. Makinwa; M. Pertijs (Ed.);
    John Wiley \& Sons, , pp. 17‒41, May 2014.
    Abstract: ...
    Smart sensors acquire information about a non-electrical quantity of interest (the measurand) and convert this information to a useful electrical output signal. In order to do so, they combine a sensing element and the associated interface electronics on a single chip or in a single package. The sensing element performs the conversion from the non-electrical domain of the measurand to an electrical signal, while the interface electronics further process this signal to produce an output that can readily be used in a measurement or control system. Errors introduced in these steps affect the performance and reliability of the overall system. Therefore, it is very important to determine how large these errors are. The process of doing so is generally referred to as calibration, and is the topic of this chapter.

    document

  45. Dedicated Impedance-Sensor Systems
    G. Meijer; X. Li; B. Iliev; G. Pop; Z. Y. Chang; S. Nihtianov; Z. Tan; A. Heidari; M. Pertijs;
    G. Meijer; K. Makinwa; M. Pertijs (Ed.);
    John Wiley \& Sons, , pp. 68‒100, 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

  46. Design of a Miniature Ultrasound Probe for 3D Transesophageal Echocardiography
    D. Bera; S. B. Raghunathan; C. Chen; S. Blaak; C. Prins; M. A. P. Pertijs; M. D. Verweij; J. G. Bosch; N. de Jong;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, April 2014.

  47. An energy-efficient reconfigurable readout circuit for resonant sensors based on ring-down measurement
    Y. Yan; Z. Zeng; C. Chen; H. Jiang; Z. Y. Chang; D. M. Karabacak; M. A. P. Pertijs;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 221‒224, October 2014. DOI: 10.1109/icsens.2014.6984973

  48. In-air ultrasonic gesture sensing with MEMS microphones
    D. M. van Willigen; E. Mostert; M. A. P. Pertijs;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 90‒93, October 2014. DOI: 10.1109/icsens.2014.6984940

  49. An eddy-current displacement-to-digital converter based on a ratio-metric delta-sigma ADC
    A. Fekri; M. Nabavi; N. Radeljic-Jakic; Z. Y. Chang; M. Pertijs; S. Nihtianov;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 403‒406, September 2014. DOI: 10.1109/esscirc.2014.6942107

  50. Capacitive sensor interface with precision references
    R. Yang; M. A. P. Pertijs; S. Nihtianov; P. Haak;
    In Proc. IEEE International Conference on Industrial Technology (ICIT),
    IEEE, pp. 358‒390, March 2014. DOI: 10.1109/icit.2014.6894896

  51. Design of a miniature ultrasound probe for 3D transesophageal echocardiography
    S. B. Raghunathan; D. Bera; C. Chen; S. Blaak; C. Prins; M. A. P. Pertijs; J. G. Bosch; N. de Jong; M. D. Verweij;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 2091‒2094, September 2014. DOI: 10.1109/ultsym.2014.0521

  52. An interface for eddy-current displacement sensors with 15-bit resolution and 20 MHz excitation
    M. R. Nabavi; M. A. P. Pertijs; S. Nihtianov;
    IEEE Journal of Solid-State Circuits,
    Volume 48, Issue 11, pp. 2868‒2881, November 2013. DOI: 10.1109/jssc.2013.2281692
    Abstract: ...
    This paper presents an integrated interface for eddy-current sensors (ECSs) for displacement measurement. The employed architecture helps bridging the performance gap between the requirements of demanding and precision industrial applications and the performance of existing ECS interfaces. The interface operates with a sensor excitation frequency of 20 MHz, which is more than one order of magnitude higher than typical values. This high excitation frequency limits the eddy-current penetration depth in the target down to a few tens of micrometers, thus enabling the use of thin targets required in precision applications. The proposed interface consists of a low-power front-end oscillator that incorporates the sensor, and a two-channel offset-compensated synchronous demodulator. A ratio-metric measurement approach along with offset and 1/f noise reduction techniques is applied to improve the system stability. The interface has been realized in a 0.35-μm 3.3 V BiCMOS technology and consumes 18 mW. Measurement results obtained using two flat sensing coils show a full-range non-linearity of the sensor interface of only 0.4\%, and a resolution of 15.5 bits (65 nm on a 3 mm measurement range), with 1 kHz signal bandwidth. This translates into 1.5 pico-Henry inductance-measurement resolution, which is comparable with the performance of the most advanced LCR meters. Using the proposed solution, a long-term instability below 20 ppm (for 17 hours) and a thermal drift of 30 ppm/°C are obtained without any temperature compensation. Compared to the state-of-the-art, the proposed interface achieves a considerably better trade-off between power consumption, resolution, bandwidth, and excitation frequency.

  53. 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.

  54. A Low-Power CMOS Smart Temperature Sensor with a Batch-Calibrated Inaccuracy of ±0.25°C (±3σ) from -70°C to 130°C
    A. Aita; M. Pertijs; K. Makinwa; J. Huijsing; G. Meijer;
    IEEE Sensors Journal,
    Volume 13, Issue 5, pp. 1840‒1848, May 2013. DOI: 10.1109/JSEN.2013.2244033
    Abstract: ...
    In this paper, a low-power CMOS smart temperature sensor is presented. The temperature information extracted using substrate PNP transistors is digitized with a resolution of 0.03°C using a precision switched-capacitor (SC) incremental ΔΣ A/D converter. After batch calibration, an inaccuracy of ±0.25°C (±3) from -70°C to 130°C is obtained. This represents a two-fold improvement compared to the state-of-the-art. After individual calibration at room temperature, an inaccuracy better than ±0.1°C over the military temperature range is obtained, which is in-line with the state-of-the-art. This performance is achieved at a power consumption of 65 μW during a measurement time of 100 ms, by optimizing the power/inaccuracy tradeoffs, and by employing a clock frequency proportional to absolute temperature. The latter ensures accurate settling of the SC input stage at low temperatures, and reduces the effects of leakage currents at high temperatures.

  55. An energy-efficient readout circuit for resonant sensors based on ring-down measurement
    Z. Zeng; M. A. P. Pertijs; D. M. Karabacak;
    Review of Scientific Instruments,
    Volume 84, Issue 2, pp. 025005, February 2013. DOI: 10.1063/1.4792396
    Abstract: ...
    This paper presents an energy-efficient readout circuit for resonant sensors that operates based on a transient measurement method. The resonant sensor is driven at a frequency close to its resonance frequency by an excitation source that can be intermittently disconnected, causing the sensor to oscillate at its resonance frequency with exponentially decaying amplitude. By counting the zero crossings of this ring-down response, the interface circuit can detect the resonance frequency. In contrast with oscillator-based readout, the presented readout circuit is readily able to detect quality factor (Q) of the resonator from the envelope of the ring-down response, and can be used even in the presence of large parasitic capacitors. A prototype of the readout circuit has been integrated in 0.35 μm CMOS technology, and consumes only 36 μA from a 3.3 V supply during a measurement time of 2 ms. The resonance frequency and quality factor of a micro-machined SiN resonator obtained using this prototype are in good agreement with results obtained using impedance analysis. Furthermore, a clear transient response is observed to ethanol flow using the presented readout, demonstrating the use of this technique in sensing applications.

  56. A 7μW pH-to-digital converter for quality monitoring of perishable products
    S. H. Shalmany; M. Merz; A. Fekri; Z. Chang; R. Hoofman; M. A. P. Pertijs;
    In Proc. International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS),
    IEEE, pp. 1747‒1750, June 2013. DOI: 10.1109/Transducers.2013.6627125
    Abstract: ...
    This paper describes an energy-efficient smart pH sensor intended for use in RFID tags to monitor the quality of perishable products. The sensor is based on an Extended Gate Field-Effect Transistor (EGFET). In a measurement time of 20 ms, it achieves a pH resolution of 0.05 and an accuracy of 0.1 in a pH range from 3 to 10, while consuming only 7 μW. This level of power consumption, which is orders of magnitude lower than the prior art, is achieved by incorporating the EGFET in an ultra-low-power frontend based on a differential source-follower, and digitizing the resulting pH-dependent voltage using an incremental first-order ΔΣ ADC.

  57. 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.

  58. 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).

  59. 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.

  60. 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.

  61. Front-end receiver electronics for a matrix transducer for 3-D transesophageal echocardiography
    Z. Yu; S. Blaak; Z. Y. Chang; J. Yao; J. G. Bosch; C. Prins; C. T. Lancee; N. de Jong; M. A. P. Pertijs; G. C. M. Meijer;
    IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control,
    Volume 59, Issue 7, pp. 1500‒1512, July 2012. DOI: 10.1109/tuffc.2012.2350
    Abstract: ...
    There is a clear clinical need for creating 3-D images of the heart. One promising technique is the use of transesophageal echocardiography (TEE). To enable 3-D TEE, we are developing a miniature ultrasound probe containing a matrix piezoelectric transducer with more than 2000 elements. Because a gastroscopic tube cannot accommodate the cables needed to connect all transducer elements directly to an imaging system, a major challenge is to locally reduce the number of channels, while maintaining a sufficient signal-to-noise ratio. This can be achieved by using front-end receiver electronics bonded to the transducers to provide appropriate signal conditioning in the tip of the probe. This paper presents the design of such electronics, realizing time-gain compensation (TGC) and micro-beamforming using simple, low-power circuits. Prototypes of TGC amplifiers and micro-beamforming cells have been fabricated in 0.35-μm CMOS technology. These prototype chips have been combined on a printed circuit board (PCB) to form an ultrasound-receiver system capable of reading and combining the signals of three transducer elements. Experimental results show that this design is a suitable candidate for 3-D TEE.

  62. Energy-Efficient Capacitive Sensor Interfaces
    M. A. P. Pertijs; Z. Tan;
    A. H. M. van Roermund; A. Baschirotto; M. Steyaert (Ed.);
    Springer Science \& Business Media, , pp. 129‒147, 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

  63. A 9-channel low-power receiver ASIC for 3D transesophageal echocardiography
    Z. Yu; S. Blaak; C. Prins; Z. Chang; C. T. Lancée, CT; J. G. Bosch; N. de Jong; G. C. M. Meijer; M. A. P. Pertijs;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 2063‒2066, October 2012. DOI: 10.1109/ultsym.2012.0516

  64. 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

  65. An energy-efficient interface for resonant sensors based on ring-down measurement
    M. A. P. Pertijs; Z. Zeng; D. M. Karabacak; M. Crego-Calama; S. H. Brongersma;
    In Proc. IEEE International Symposium on Circuits and Systems (ISCAS),
    IEEE, pp. 990‒993, May 2012. (invited paper). DOI: 10.1109/iscas.2012.6272213

  66. Energy-Efficient Capacitive Sensor Interfaces
    M. A. P. 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

  67. Oven Controlled MEMS Oscillator Device
    S. Donnay; X. Rottenberg; J. Borremans; H. Tilmans; G. van der Plas; M. Pertijs;
    Patent, United States 13/150,499, December~6 2012.

  68. Oven controlled MEMS oscillator
    S. Donnay; X. Rottenberg; J. Borremans; H. Tilmans; G. van der Plas; M. Pertijs;
    Patent, European 2,530,836, December~5 2012.

  69. Ultrasound beamformer using pipeline-operated S/H delay stages and charge-mode summation
    Z. Yu; M. A. P. Pertijs; G. C. M. Meijer;
    Electronics Letters,
    Volume 47, Issue 18, pp. 1011‒1012, September 2011. DOI: 10.1049/el.2011.1786
    Abstract: ...
    The proposed ultrasound beamformer is based on the delay-and-sum beamforming principle. The circuit consists of several programmable delay lines. Each delay line is constructed by pipeline-operated sample-and-hold (S/H) stages with digitally-assisted delay control, which ensure delay-independent gain and good timing accuracy. The summation is realised in the charge domain using the charge-averaging method, which consumes virtually no extra die area or power. A prototype beamformer has been fabricated in a 0.35 m CMOS process to interface nine transducer elements. Measurement results show that this circuit consumes much less power and chip area than the prior art, while maintaining good accuracy and flexibility.

  70. A Single-Temperature Trimming Technique for MOS-Input Operational Amplifiers Achieving 0.33μV/°C Offset Drift
    M. Bolatkale; M. A. P. Pertijs; W. J. Kindt; J. H. Huijsing; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 46, Issue 9, pp. 2099‒2107, September 2011. DOI: 10.1109/JSSC.2011.2139530
    Abstract: ...
    A MOS-input operational amplifier has a reconfigurable input stage that enables trimming of both offset and offset drift based only on single-temperature measurements. The input stage consists of a MOS differential pair, whose offset drift is predicted from offset voltage measurements made at well-defined bias currents. A theoretical motivation for this approach is presented and validated experimentally by characterizing the offset of pairs of discrete MOS transistors as a function of bias current and temperature. An opamp using the proposed single-temperature trimming technique has been designed and fabricated in a 0.5 μm BiCMOS process. After single-temperature trimming, it achieves a maximum offset of ± 30 μV and an offset drift of 0.33 μV/°C (3σ) over the temperature range of -40°C to +125°C.

  71. A Ratio-metric Analog to Digital Converter for an Eddy Current Displacement Sensor
    A. Fekri; M. R. Nabavi; M. Pertijs; S. Nihtianov;
    In Proc. International Scientific Conference on Electronics,
    Sozopol, Bulgaria, September 2011.

  72. 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.

  73. Light-emitting diode junction-temperature sensing using differential voltage/current measurements
    F. D. Roscam-Abbing; M. A. P. Pertijs;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 861‒864, October 2011. DOI: 10.1109/icsens.2011.6127191

  74. 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

  75. A ping-pong-pang current-feedback instrumentation amplifier with 0.04\% gain error
    S. Sakunia; F. Witte; M. Pertijs; K. Makinwa;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    IEEE, pp. 60‒61, June 2011.
    Abstract: ...
    A ping-pong-pang auto-zeroed and chopped current-feedback instrumentation amplifier (CFIA) uses three dynamically-matched input stages to achieve 0.04\% gain error, a 2.5× improvement over prior art. Its 4 μV offset and 28 nV/√Hz noise are achieved at 3.5× less supply current than a comparable ping-pong auto-zeroed CFIA.

    document

  76. Ovenized System Containing Micro-Electromechanical Resonator
    J. Borremans; M. A. P. Pertijs;
    Patent, United States 13/300,950, November~21 2011.

  77. A Thermal-Diffusivity-Based Frequency Reference in Standard CMOS With an Absolute Inaccuracy of ±0.1\% From -55°C to 125°C
    S. M. Kashmiri; M. A. P. Pertijs; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 45, Issue 12, pp. 2510‒2520, December 2010. DOI: 10.1109/JSSC.2010.2076343
    Abstract: ...
    An on-chip frequency reference exploiting the well-defined thermal-diffusivity (TD) of IC-grade silicon has been realized in a standard 0.7 μm CMOS process. A frequency-locked loop (FLL) locks the frequency of a digitally controlled oscillator (DCO) to the process-insensitive phase shift of an electrothermal filter (ETF). The ETF's phase shift is determined by its geometry and by the thermal diffusivity of bulk silicon (D). The temperature dependence of is compensated for with the help of die-temperature information obtained by an on-chip band-gap temperature sensor. The resulting TD frequency reference has a nominal output frequency of 1.6 MHz and dissipates 7.8 mW from a 5 V supply. Measurements on 16 devices show that it has an absolute inaccuracy of ±0.1\% (σ = ±0.05\%) over the military temperature range (-55°C to 125°C ), with a worst case temperature coefficient of ± 11.2 ppm/°C.

  78. A 140 dB-CMRR current-feedback instrumentation amplifier employing ping-pong auto-zeroing and chopping
    M. A. P. Pertijs; W. J. Kindt;
    IEEE Journal of Solid-State Circuits,
    Volume 45, Issue 10, pp. 2044‒2056, October 2010. DOI: 10.1109/jssc.2010.2060253
    Abstract: ...
    This paper presents a precision general-purpose current-feedback instrumentation amplifier (CFIA) that employs a combination of ping-pong auto-zeroing and chopping to cancel its offset and 1/f noise. A comparison of offset-cancellation techniques shows that neither chopping nor auto-zeroing is an ideal solution for general-purpose CFIAs, since chopping results in output ripple, and auto-zeroing is associated with increased low-frequency noise. The presented CFIA mitigates these unintended side effects through a combination of these techniques. A ping-pong auto-zeroed input stage with slow-settling offset-nulling loops is applied to limit the bandwidth of the increased noise to less than half of the auto-zeroing frequency. This noise is then modulated away from DC by chopping the input stage at half the auto-zeroing frequency, reducing the low-frequency noise to the 27 nV/ white-noise level, without introducing extra output ripple. The auto-zeroing is augmented with settling phases to further reduce output transients. The CFIA was realized in a 0.5 μm analog CMOS process and achieves a typical offset of 2.8 μV and a CMRR of 140 dB in a common-mode voltage range that includes the negative supply.

  79. Low-cost calibration techniques for smart temperature sensors
    M. A. P. Pertijs; A. L. Aita; K. A. A. Makinwa; J. H. Huijsing;
    IEEE Sensors Journal,
    Volume 10, Issue 6, pp. 1098‒1105, June 2010. DOI: 10.1109/jsen.2010.2040730
    Abstract: ...
    Smart temperature sensors generally need to be trimmed to obtain measurement errors below ±2°C. The associated temperature calibration procedure is time consuming and therefore costly. This paper presents two, much faster, voltage calibration techniques. Both make use of the fact that a voltage proportional to absolute temperature (PTAT) can be accurately generated on chip. By measuring this voltage, the sensor's actual temperature can be determined, whereupon the sensor can be trimmed to correct for its dominant source of error: spread in the on-chip voltage reference. The first calibration technique consists of measuring the (small) PTAT voltage directly, while the second, more robust alternative does so indirectly, by using an external reference voltage and the on-chip ADC. Experimental results from a prototype fabricated in 0.7 μm CMOS technology show that after calibration and trimming, these two techniques result in measurement errors (±3σ) of ±0.15°C and ±0.25°C, respectively, in a range from -55°C to 125°C.

  80. 12-bit accurate voltage-sensing ADC with curvature-corrected dynamic reference
    N. Saputra; M. A. P. Pertijs; K. A. A. Makinwa; J. H. Huijsing;
    Electronics Letters,
    Volume 46, Issue 6, pp. 397‒398, March 2010. DOI: 10.1049/el.2010.3337
    Abstract: ...
    A sigma-delta analogue-to-digital converter (ADC) with a dynamic voltage reference is presented that achieves 12-bit absolute accuracy over the extended industrial temperature range (-40 to 105°C). Temperature-dependent gain errors due to the reference's curvature are digitally corrected by adjusting the gain of the ADC's decimation filter. The required correction factor is obtained by first using the reference to make a temperature measurement, and then translating the result into a correction factor by means of a lookup table and a linear interpolator. Thus, a dynamic voltage reference is realised with a measured temperature drift of less than 1.7 ppm/°C. The ADC was fabricated in 0.7 μm CMOS technology and consumes 85 μA from a 2.5-5.5 V supply.

  81. Design of a Beamformer for an Ultrasonic Matrix Transducer for 3D Transesophageal Echocardiography
    Z. Yu; S. Blaak; G. C. M. Meijer; M. A. P. Pertijs; C. T. Lancée, CT; J. G. Bosch; C. Prins; N. de Jong;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, April 2010. (Best Poster Award).

  82. 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.

  83. A programmable analog delay line for Micro-beamforming in a transesophageal ultrasound probe
    Z. Yu; M. A. P. Pertijs; G. C. M. Meijer;
    In Proc. IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT),
    IEEE, pp. 299‒301, November 2010. DOI: 10.1109/icsict.2010.5667749

  84. Design of a low power time-gain-compensation amplifier for a 2D piezoelectric ultrasound transducer
    J. Yao; Z. Yu; M. A. P. Pertijs; G. C. M. Meijer; C. T. Lancee; J. G. Bosch; N. de Jong;
    In Proc. IEEE International Ultrasonics Symposium (IUS),
    IEEE, pp. 841‒844, October 2010. DOI: 10.1109/ultsym.2010.5935775

  85. An interface for eddy current displacement sensors with 15-bit resolution and 20 MHz excitation
    M. R. Nabavi; M. A. P. Pertijs; S. Nihtianov;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 290‒293, September 2010. DOI: 10.1109/esscirc.2010.5619835

  86. A Thermal-diffusivity-based Frequency Reference in Standard CMOS with an Absolute Inaccuracy of ±0.1\% from -55°C to 125°C
    M. Kashmiri; M. Pertijs; K. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 74‒75, February 2010. DOI: 10.1109/ISSCC.2010.5434042
    Abstract: ...
    Most electronic systems require a frequency reference, and so, much research has been devoted to the realization of on-chip frequency references in standard CMOS. However, the accuracy of such references is limited by the process spread and temperature drift of on-chip components. By means of trimming and temperature compensation, RC and ring oscillators have achieved inaccuracies in the order of 1\%. LC oscillators achieve inaccuracies below 0.1\%, but dissipate much more power. This paper describes a new approach, which exploits the well-defined thermal diffusivity of IC-grade silicon in order to generate frequencies stable to 0.1\% over process and temperature variations. Such thermal diffusivity (TD) frequency references dissipate less power than LC oscillators, are more accurate than RC and ring oscillators and, uniquely, scale well with process.

  87. Chopped auto-zeroed ping-pong amplifier and related apparatus, system, and method
    M. A. P. Pertijs;
    Patent, United States 7,834,685, November~16 2010.

  88. Current sense amplifier with extended common mode voltage range
    W. J. Kindt; M. A. P. Pertijs;
    Patent, United States 7,671,677, March~2 2010.

  89. Digital temperature sensors and calibration thereof
    M. Pertijs; J. Huijsing;
    Patent, United States 7,674,035, March~9 2010.

  90. Digitale temperatursensoren und kalibrierung dafür
    M. A. P. Pertijs; J. H. Huijsing;
    Patent, German 602,005,020,159, May~6 2010.

  91. Autozeroing current feedback instrumentation amplifier
    M. Pertijs; G. Reitsma;
    Patent, United States 7,719,351, May~18 2010.

  92. Integrated circuit with pin-selectable mode of operation and level-shift functionality and related apparatus, system, and method
    M. A. P. Pertijs;
    Patent, United States 7,714,612, May~11 2010.

  93. Bias-steuerung
    M. A. P. Pertijs; J. H. Huijsing;
    Patent, German 602,005,018,235, January~21 2010.

  94. A 140dB-CMRR current-feedback instrumentation amplifier employing ping-pong auto-zeroing and chopping
    M. A. P. Pertijs; W. J. Kindt;
    In Highlights of ISSCC 2009,
    Eindhoven, The Netherlands, March 2009.

  95. A 140dB-CMRR current-feedback instrumentation amplifier employing ping-pong auto-zeroing and chopping
    M. A. P. Pertijs; W. J. Kindt;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 324‒325, February 2009. DOI: 10.1109/isscc.2009.4977439

  96. A CMOS smart temperature sensor with a batch-calibrated inaccuracy of ±0.25°C (3σ) from -70°C to 130°C
    A. L. Aita; M. Pertijs; K. Makinwa; J. H. Huijsing;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 342‒343, February 2009. DOI: 10.1109/ISSCC.2009.4977448
    Abstract: ...
    A major contributor to the total cost of precision CMOS temperature sensors is the cost of trimming and calibration. Significant cost savings can be obtained by batch calibration, but this is usually at the expense of an equally significant loss of accuracy. This paper presents a CMOS temperature sensor with a batch-calibrated inaccuracy of ±0.25°C (3σ) from -70°C to 130°C, which represents a 2x improvement over the state of the art. Individual trimming reduces the sensor's inaccuracy to ±0.1°C (3σ) over the military range: -55°C to 125°C. The sensor draws 25μA from a 2.5V to 5.5V supply, which is significantly less than commercial products with comparable accuracy.

  97. Autozeroing current feedback instrumentation amplifier
    M. Pertijs; G. Reitsma;
    Patent, United States 7,573,327, August~11 2009.

  98. Strom-Rückkopplungs-Instrumentenverstärker mit selbsttätiger Nullpunkt-Einstellung
    M. Pertijs; G. Reitsma;
    Patent, German 102,008,023,384, January~29 2009.

  99. Voltage calibration of smart temperature sensors
    M. A. P. Pertijs; A. L. Aita; K. A. A. Makinwa; J. H. Huijsing;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 756‒759, October 2008. DOI: 10.1109/icsens.2008.4716551

  100. Sigma delta ADC with a dynamic reference for accurate temperature and voltage sensing
    N. Saputra; M. A. P. Pertijs; K. A. A. Makinwa; J. H. Huijsing;
    In Proc. IEEE International Symposium on Circuits and Systems (ISCAS),
    IEEE, pp. 1208‒1211, May 2008. DOI: 10.1109/iscas.2008.4541641

  101. A BiCMOS Operational Amplifier Achieving 0.33μV/°C Offset Drift using Room-Temperature Trimming
    M. Bolatkale; M. A. P. Pertijs; W. J. Kindt; J. H. Huijsing; K. A. A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 76‒77, February 2008. DOI: 10.1109/isscc.2008.4523064

  102. Bias circuits
    M. Pertijs; J. Huijsing;
    Patent, United States 7,446,598, November~4 2008.

  103. Bitstream controlled reference signal generation for a sigma-delta modulator
    M. A. P. Pertijs; K. A. A. Makinwa; J. H. Huijsing;
    Patent, United States 7,391,351, June~24 2008.

  104. Smart sensor design: the art of compensation and cancellation
    K. A. A. Makinwa; M. A. P. Pertijs; J. C. van der Meer; J. H. Huijsing;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 76‒82, September 2007. DOI: 10.1109/esscirc.2007.4430251

  105. Precision temperature sensors in CMOS technology
    M. A. P. Pertijs; J. H. Huijsing;
    Springer Science \& Business Media, , 2006.
    Abstract: ...
    The low cost and direct digital output of CMOS smart temperature sensors are important advantages compared to conventional temperature sensors. This book addresses the main problem that nevertheless prevents widespread application of CMOS smart temperature sensors: their relatively poor absolute accuracy. Several new techniques are introduced to improve this accuracy. The effectiveness of these techniques is demonstrated using three prototypes. The final prototype achieves an inaccuracy of ±0.1 °C over the military temperature range, which is a significant improvement in the state of the art. Since smart temperature sensors have been the subject of academic and industrial research for more than two decades, an overview of existing knowledge and techniques is also provided throughout the book.

    document

  106. Sigma Delta ADC with Accurate Dynamic Reference for Temperature Sensing and Voltage Monitoring
    N. Saputra; M. A. P. Pertijs; K. A. A. Makinwa; J. H. Huijsing;
    In Annual Workshop on Circuits, Systems and Signal Processing (ProRISC),
    The Netherlands, pp. 80‒84, November 2006.

  107. A CMOS smart temperature sensor with a 3σ inaccuracy of ±0.1°C from -55°C to 125°C
    M. A. P. Pertijs; K. A. A. Makinwa; J. H. Huijsing;
    IEEE Journal of Solid-State Circuits,
    Volume 40, Issue 12, pp. 2805‒2815, December 2005. (JSSC Best Paper Award). DOI: 10.1109/JSSC.2005.858476
    Abstract: ...
    A smart temperature sensor in 0.7 μm CMOS is accurate to within ±0.1°C (3σ) over the full military temperature range of -55°C to 125°C. The sensor uses substrate PNP transistors to measure temperature. Errors resulting from nonidealities in the readout circuitry are reduced to the 0.01°C level. This is achieved by using dynamic element matching, a chopped current-gain independent PTAT bias circuit, and a low-offset second-order sigma-delta ADC that combines chopping and correlated double sampling. Spread of the base-emitter voltage characteristics of the substrate PNP transistors is compensated by trimming, based on a calibration at one temperature. A high trimming resolution is obtained by using a sigma-delta current DAC to fine-tune the bias current of the bipolar transistors.

  108. A CMOS smart temperature sensor with a 3σ inaccuracy of ±0.5°C from -50°C to 120°C
    M. A. P. Pertijs; A. Niederkorn; X. Ma; B. McKillop; A. Bakker; J. H. Huijsing;
    IEEE Journal of Solid-State Circuits,
    Volume 40, Issue 2, pp. 454‒461, February 2005. DOI: 10.1109/JSSC.2004.841013
    Abstract: ...
    A low-cost temperature sensor with on-chip sigma-delta ADC and digital bus interface was realized in a 0.5 μm CMOS process. Substrate PNP transistors are used for temperature sensing and for generating the ADC's reference voltage. To obtain a high initial accuracy in the readout circuitry, chopper amplifiers and dynamic element matching are used. High linearity is obtained by using second-order curvature correction. With these measures, the sensor's temperature error is dominated by spread on the base-emitter voltage of the PNP transistors. This is trimmed after packaging by comparing the sensor's output with the die temperature measured using an extra on-chip calibration transistor. Compared to traditional calibration techniques, this procedure is much faster and therefore reduces production costs. The sensor is accurate to within ±0.5°C (3σ) from -50°C to 120°C.

  109. Precision interface electronics for a CMOS smart temperature sensor
    M. A. P. Pertijs; J. H. Huijsing;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 4‒pp, October 2005. (invited paper). DOI: 10.1109/ICSENS.2005.1597856
    Abstract: ...
    This paper describes the interface electronics of a CMOS smart temperature sensor that is accurate to plusmn0.1degC over the full military temperature range. The sensor is fabricated in a standard CMOS process. Substrate bipolar transistors are used as temperature-sensitive devices. Precision interface electronics are used to make the most of their temperature characteristics. While the sensor is trimmed at one temperature, its accuracy over the full temperature range depends on the initial accuracy of the electronics. Dynamic offset cancellation and dynamic element matching are used to eliminate offset and gain errors. These techniques are combined with a sigma-delta ADC to obtain a readily usable digital temperature reading

  110. A CMOS temperature sensor with a 3σ inaccuracy of ±0.1°C from -55°C to 125°C
    M. Pertijs; K. Makinwa; J. Huijsing;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 238‒596, February 2005. ({ISSCC} 2005 {Jack} {Kilby} Award for Outstanding Student Paper). DOI: 10.1109/ISSCC.2005.1493957
    Abstract: ...
    A smart temperature sensor is accurate to within ±0.1°C (3σ) over the full military temperature range of -55°C to 125°C. This 5x improvement is achieved using DEM, a current-gain independent PTAT bias circuit, and a low-offset ΔΣ ADC combining chopping and CDS. The sensor is fabricated in 0.7μm 2M1P CMOS with 4.5mm² area and draws 75μA.

  111. Precision temperature measurement using CMOS substrate PNP transistors
    M. A. P. Pertijs; G. C. M. Meijer; J. H. Huijsing;
    IEEE Sensors Journal,
    Volume 4, Issue 3, pp. 294‒300, June 2004. DOI: 10.1109/jsen.2004.826742
    Abstract: ...
    This paper analyzes the nonidealities of temperature sensors based on substrate pnp transistors and shows how their influence can be minimized. It focuses on temperature measurement using the difference between the base-emitter voltages of a transistor operated at two current densities. This difference is proportional to absolute temperature (PTAT). The effects of series resistance, current-gain variation, high-level injection, and the Early effect on the accuracy of this PTAT voltage are discussed. The results of measurements made on substrate pnp transistors in a standard 0.5μm CMOS process are presented to illustrate the effects of these nonidealities. It is shown that the modeling of the PTAT voltage can be improved by taking the temperature dependency of the effective emission coefficient into account using the reverse Early effect. With this refinement, the temperature can be extracted from the measurement data with an absolute accuracy of ±0.1°C in the range of -50 to 130°C.

  112. Low-cost calibration techniques for smart temperature sensors
    M. A. P. Pertijs; J. H. Huijsing;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, pp. 17, March 2004.

  113. A CMOS Semi-Custom Chip for Mixed Signal Designs
    A. J. van Genderen; S. D. Cotofana; G. de Graaf; A. Kaichouhi; J. Liedorp; R. Nouta; M. A. P. Pertijs; C. J. M. Verhoeven;
    In Annual Workshop on Circuits, Systems and Signal Processing (ProRISC),
    The Netherlands, pp. 491‒496, November 2004.

  114. Bitstream trimming of a smart temperature sensor
    M. A. P. Pertijs; J. H. Huijsing;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 904‒907, October 2004. DOI: 10.1109/ICSENS.2004.1426317
    Abstract: ...
    The paper presents a high-resolution trimming technique for use in precision smart temperature sensors. A digital sigma-delta modulator is used to trim the bias current of a bipolar transistor to compensate for process spread. In contrast with conventional trimming techniques, only a small chip area is required. The implementation of this technique in a temperature sensor with a sigma-delta ADC is discussed. On a prototype realized in 0.7μm CMOS, an 8-bit trimming resolution was measured, corresponding to 0.02°C on a range of 4.5°C.

  115. A second-order sigma-delta ADC using MOS capacitors for smart sensor applications
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 421‒424, October 2004. DOI: 10.1109/ICSENS.2004.1426189
    Abstract: ...
    This paper presents a second-order sigma-delta ADC designed for use in a smart temperature sensor. It is operated in a 'one-shot' mode, i.e. the converter is powered up, produces a single conversion result, and powers down again. This paper discusses the implications of this mode of operation for the design of the modulator and the decimation filter. A sinc² decimation filter is used, which is shown to provide a higher resolution then a more complex sinc³ with the same conversion time. Through continuous-time integration of the input and reference voltages, the use of a linear sampling capacitor at the input is avoided. The modulator was implemented in a 0.5μm digital CMOS process using MOS capacitors. An effective resolution of 15.5 bits was measured with a conversion time of 25 ms.

  116. A sigma-delta modulator with bitstream-controlled dynamic element matching
    M. A. P. Pertijs; J. H. Huijsing;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    IEEE, pp. 187‒190, September 2004. DOI: 10.1109/ESSCIR.2004.1356649
    Abstract: ...
    When dynamic element matching (DEM) techniques are applied to generate a precision reference for a (single-bit) sigma-delta modulator, intermodulation occurs between the DEM residuals and the bitstream, which increases the in-band quantization noise. This can be prevented by deriving the sequence of DEM steps from the bitstream. This technique has been implemented in a second-order sigma-delta modulator with a dynamic bandgap voltage reference, which was realized in a 0.7μm CMOS process. Measurements show complete elimination of intermodulation products in the signal band, corresponding to an 8 dB reduction in quantization noise compared to conventional cyclic DEM.

  117. A high-accuracy CMOS smart temperature sensor with fast calibration procedure
    M. A. P. Pertijs; A. Niederkorn; X. Ma; B. McKillop; A. Bakker; J. Huijsing;
    In Annual Sensor Technology Workshop Sense of Contact,
    The Netherlands, pp. 37, March 2003.

  118. A CMOS temperature sensor with a 3σ inaccuracy of ±0.5°C from -50°C to 120°C
    M. Pertijs; A. Niederkorn; X. Ma; B. McKillop; A. Bakker; J. Huijsing;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 200‒201, February 2003. DOI: 10.1109/ISSCC.2003.1234266
    Abstract: ...
    A temperature sensor in 0.5μm CMOS achieves an accuracy of ±0.5°C (3σ) from -50°C to 120°C. It combines chopping, dynamic element matching and curvature correction with calibration at room temperature. Calibration time has been reduced to less than 1s by using an on-chip transistor to measure the die temperature.

  119. Calibration of Smart Temperature Sensors Using an On-Chip Transistor as Reference Thermometer
    M. A. P. Pertijs; J. H. Huijsing;
    In Annual Workshop on Semiconductor Sensors (SeSens),
    The Netherlands, pp. 657-661, November 2002.

  120. Calibration and self-calibration of smart sensors
    M. A. P. Pertijs;
    In Proc. NMI Workshop Internet Measurement and Self-Calibration,
    The Netherlands, May 2002.

  121. Non-idealities of temperature sensors using substrate PNP transistors
    M. A. P. Pertijs; G. C. M. Meijer; J. H. Huijsing;
    In Proc. IEEE Sensors Conference,
    IEEE, pp. 1018‒1023, June 2002. DOI: 10.1109/ICSENS.2002.1037251
    Abstract: ...
    This paper describes the nonidealities of temperature sensors based on substrate pnp transistors and shows how their influence can be minimized The effects of series resistance, current-gain variation, high-level injection and the Early effect on the accuracy of the PTAT voltage are discussed. The results of measurements made on substrate pnp transistors in a standard 0.5μm CMOS process are presented to show the effects of these nonidealities. It is shown that the modeling of the PTAT voltage can be improved by taking the temperature dependency of the effective emission coefficient into account using the reverse Early effect. With this refinement, the temperature can be extracted from the measurement data with an absolute accuracy of ±0.1°C in the range of -50°C to 130°C.

  122. Transistor temperature measurement for calibration of integrated temperature sensors
    M. A. P. Pertijs; J. H. Huijsing;
    In Proc. IEEE Instrumentation and Measurement Technology Conference (IMTC),
    IEEE, pp. 755‒758, May 2002. DOI: 10.1109/IMTC.2002.1006936
    Abstract: ...
    A temperature measurement technique is presented for calibrating packaged integrated temperature sensors. An on-chip bipolar transistor is used to accurately determine the sensor's temperature during calibration. The transistor's base-emitter voltage is measured at three collector currents to find the absolute temperature while compensating for series resistances. The technique does not increase the pin count for a typical smart sensor, as the transistor can be accessed via the supply pins and an existing digital input pin. Measurements on substrate pnp's in a standard CMOS process show that the temperature can be determined with an accuracy of ±0.1°C in the range of -50°C to 130°C.

  123. Non-linear signal correction
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    Patent, United States 6,456,145, September~24 2002.

  124. A batch-calibrated smart temperature sensor with second-order curvature correction
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    In Annual Workshop on Semiconductor Sensors (SeSens),
    The Netherlands, pp. 852‒855, November 2001.

  125. An Accurate CMOS Smart Temperature Sensor with Dynamic Element Matching and Second-Order Curvature Correction
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    In Proc. International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS),
    Springer Berlin Heidelberg, pp. 80‒83, June 2001. DOI: 10.1007/978-3-642-59497-7_18
    Abstract: ...
    A CMOS temperature sensor with digital bus interface is presented that combines dynamic element matching and second-order curvature correction to improve the accuracy. An error analysis is presented which shows that the remaining inaccuracy is determined by the process spread of substrate bipolar transistors. This spread is significantly less within a batch than between batches. Therefore, all sensors within a batch can be calibrated in the same way, leading to a three-sigma accuracy of ±1.5°C in the range of −50 to 120°C.

  126. A high-accuracy temperature sensor with second-order curvature correction and digital bus interface
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    In Proc. IEEE International Symposium on Circuits and Systems (ISCAS),
    IEEE, pp. 368‒371, May 2001. DOI: 10.1109/ISCAS.2001.921869
    Abstract: ...
    A high-accuracy CMOS temperature sensor with integrated bus interface is presented. It is shown that when offset cancellation and dynamic element matching techniques are applied, the accuracy of the sensor is mainly limited by process spread between batches on the substrate bipolar transistors. Therefore, the sensors can be calibrated per batch instead of per sensor. In combination with a second-order curvature correction technique, this results in a three-sigma accuracy of ±1.5°C over the full temperature range.

  127. Non-linear signal correction
    M. A. P. Pertijs; A. Bakker; J. H. Huijsing;
    Patent, WO PCT/EP2001/011,288, September~27 2001.

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