MSc U. Sonmez

PhD student
Electronic Instrumentation (EI), Department of Microelectronics

PhD thesis (Mar 2020): Compact Thermal Diffusivity Sensors for On-Chip Thermal Management
Promotor: Kofi Makinwa, Fabio Sebastiano

Expertise: Thermal-diffusivity-based frequency references and temperature sensors


Ugur Sonmez was born in Istanbul, Turkey on 3 April 1986, and graduated from the Uskudar American Academy high school in 2004. He obtained B.Sc. and M.Sc. degrees in electronics from Middle East Technical University, Ankara, Turkey in 2008 and 2011, respectively. His M.Sc. thesis was on readout circuits for capacitive MEMS accelerometers. In August 2011, he joined the Electronic Instrumentation Laboratory, where he is currently working towards a PhD in the area of thermal-diffusivity-based frequency references and temperature sensors. His non-research interests currently include cycling, music and high fidelity music reproduction, history, mythology, and table-top RPGs.


  1. Analysis and Design of VCO-Based Phase-Domain ΣΔ Modulators
    U. Sonmez; F. Sebastiano; K. Makinwa;
    IEEE Transactions on Circuits and Systems I,
    Volume 64, pp. 1075-1084, 5 2017. DOI: 10.1109/TCSI.2016.2638827

  2. Compact Thermal-Diffusivity-Based Temperature Sensors in 40-nm CMOS for SoC Thermal Monitoring
    U. Sonmez; F. Sebastiano; K. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 52, Issue 3, pp. 834-843, March 2017. DOI: 10.1109/jssc.2016.2646798

  3. 1650µm² Thermal-Diffusivity Sensors with Inaccuracies Down to ±0.75°C in 40nm CMOS
    U. Sonmez; F. Sebastiano; K.A.A. Makinwa;
    In 2016 IEEE International Solid-State Circuits Conference (ISSCC),
    IEEE, pp. 206-207, Feb 2016. DOI: 10.1109/ISSCC.2016.7417979

  4. A 4600µm² 1.5°C (3σ) 0.9kS/s thermal-diffusivity temperature sensor with VCO-based readout
    Rui Quan; Ugur Sonmez; Fabio Sebastiano and, Kofi A.A. Makinwa;
    In International Solid-state Circuits Conference Digest of Technical Papers,
    San Francisco, CA, pp. 488 - 489, Feb 2015. DOI: 10.1109/ISSCC.2015.7063139
    Keywords: ... Accuracy;CMOS integrated circuits;Modulation;Radiation detectors;Temperature sensors.

    Abstract: ... This paper presents a highly digital thermal-diffusivity temperature sensor in 0.16µm CMOS for SoC thermal monitoring. The sensor occupies only 4600µm², which is the smallest for designs above 32nm and is one of the smallest ever reported. It also achieves ±1.5°C (3σ, single trim) inaccuracy and 0.6$^circ$C resolution at a 0.9kS/s sampling rate. This small area implementation is mainly enabled by the adoption of a VCO-based phase-domain ADC whose area is 70% digital.

  5. A 2800-µm² Thermal-Diffusivity Temperature Sensor with VCO-Based Readout in 160-nm CMOS
    Jan Angevare; Lorenzo Pedalà; Ugur Sonmez; Fabio Sebastiano; Kofi A.A. Makinwa;
    In Asian Solid-state Circuits Conference Digest of Technical Papers,
    Xiamen, China, pp. 1-4, Nov 2015. DOI: 10.1109/ASSCC.2015.7387444
    Keywords: ... CMOS digital integrated circuits;analogue-digital conversion;computerised monitoring;digital readout;temperature sensors;thermal diffusivity;voltage-controlled oscillators;VCO-based phase-domain ADC;VCO-based readout;bulk silicon;digital circuitry;highly digital temperature sensor;microprocessors;size 160 nm;standard CMOS process;systems-on-chip;temperature -35 degC to 125 degC;temperature-dependent thermal diffusivity;thermal monitoring;CMOS integrated circuits;CMOS process;Heating;Radiation detectors;Temperature measurement;Temperature sensors.

    Abstract: ... A highly digital temperature sensor based on the temperature-dependent thermal diffusivity of bulk silicon has been realized in a standard 160-nm CMOS process. The sensor achieves an inaccuracy of 2.9C (3a) from -35C to 125C with no trimming and 1.2C (3a) after a single-point trim, while achieving a resolution of 0.47C (rms) at 1 kSa/s. Its compact area (2800 m2) is enabled by the adoption of a VCO-based phase-domain ADC. Since 53% of the sensor area is occupied by digital circuitry, the sensor can be easily ported to more advanced CMOS technologies with further area reduction, which makes it well suited for thermal monitoring in microprocessors and other systems-on-chip.

  6. 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

  7. A 0.008-mm² area-optimized thermal-diffusivity-based temperature sensor in 160-nm CMOS for SoC thermal monitoring
    Ugur Sonmez; Rui Quan; Fabio Sebastiano; Kofi. A. A. Makinwa;
    In Proc. European Solid-State Circuits Conference,
    Venice, Italy, pp. 395-398, September22--26 2014. DOI: 10.1109/ESSCIRC.2014.6942105
    Keywords: ... CMOS integrated circuits;system-on-chip;temperature measurement;temperature sensors;thermal diffusivity;SoC thermal monitoring;area-optimized thermal-diffusivity-based temperature sensor;bulk silicon;microprocessors;size 160 nm;standard CMOS process;systems-on-chip;temperature-dependent thermal diffusivity;thermal monitoring;Accuracy;Heating;System-on-chip;Temperature measurement;Temperature sensors.

    Abstract: ... An array of temperature sensors based on the temperature-dependent thermal diffusivity of bulk silicon has been realized in a standard 160-nm CMOS process. The sensors achieve an inaccuracy of ±2.4 °C (3σ) from -40 to 125 °C with no trimming and ±0.65 °C (3σ) with a one temperature trim. Each sensor occupies 0.008 mm², and achieves a resolution of 0.21 °C (rms) at 1 kSa/s. This combination of accuracy, speed, and small size makes such sensors well suited for thermal monitoring in microprocessors and other systems-on-chip.

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Last updated: 13 Jul 2020

Ugur Sonmez

  • Left in 2017