dr. S. Pan

1. A PNP-Based Temperature Sensor With Continuous-Time Readout and ± 0.1 °C (3σ) Inaccuracy From -55 °C to 125 °C
   Toth, Nandor G.; Tang, Zhong; Someya, Teruki; Pan, Sining; Makinwa, Kofi A. A.;
   IEEE Journal of Solid-State Circuits,
   pp. 1-10, 2024. DOI: 10.1109/JSSC.2024.3402131
   
   Keywords: ...

   Temperature sensors; Resistors; Energy efficiency; Instruments; Temperature dependence; Modulation; Energy resolution;Bitstream-controlled (BSC) dynamic-element-matching (DEM);continuous-time (CT) ΔΣ-modulator; current-mode readout; PNP-based temperature sensor; resistor ratio self-calibration.
   
   
   Abstract: ...

   This article describes a PNP-based temperature sensor that achieves both high energy efficiency and accuracy. Two resistors convert the CTAT and PTAT voltages generated by a PNP-based front-end into two currents whose ratio is then digitized by a continuous-time (CT) ΔΣ-modulator. Chopping and dynamic-element-matching (DEM) are used to mitigate the effects of component mismatch and 1/f noise, while the spread in VBE and in the ratio of the two resistors is digitally trimmed at room temperature (RT). Fabricated in a 0.18 μm CMOS process, the sensor occupies 0.12 mm2, and draws 9.5 μA from a supply voltage ranging from 1.7 to 2.2 V. Measurements on 40 samples from one batch show that it achieves an inaccuracy of ±0.1 °C (3σ ) from −55 °C to 125 °C, and a commensurate supply sensitivity of only 0.01 °C/V. Furthermore, it achieves high energy efficiency, with a resolution Figure of Merit (FoM) of 0.85 pJ·K2.

2. A Sub-1 V Capacitively Biased BJT-Based Temperature Sensor With an Inaccuracy of ±0.15°C (3σ) from −55°C to 125°C
   Tang, Zhong; Pan, Sining; Grubor, Miloš; Makinwa, Kofi A. A.;
   IEEE Journal of Solid-State Circuits,
   pp. 1-9, 2023. DOI: 10.1109/JSSC.2023.3308554

3. A Compact 10-MHz RC Frequency Reference With a Versatile Temperature Compensation Scheme
   Pan, Sining; An, Xiaomeng; Yu, Zheru; Jiang, Hui; Makinwa, Kofi A. A.;
   IEEE Journal of Solid-State Circuits,
   pp. 1-9, 2023. DOI: 10.1109/JSSC.2023.3322307

4. A BJT-Based Temperature Sensor with±0.1°C (3σ) Inaccuracy from -55°C to 125°C and a 0.85pJ.K2 Resolution FoM Using Continuous-Time Readout
   Toth, Nandor G.; Tang, Zhong; Someya, Teruki; Pan, Sining; Makinwa, Kofi A. A.;
   In 2023 IEEE International Solid-State Circuits Conference (ISSCC),
   pp. 358-360, 2023. DOI: 10.1109/ISSCC42615.2023.10067457

5. A Sub-1V 810nW Capacitively-Biased BJT-Based Temperature Sensor with an Inaccuracy of ±0.15°C (3σ) from −55°C to 125°C
   Tang, Zhong; Pan, Sining; Makinwa, Kofi A. A.;
   In 2023 IEEE International Solid-State Circuits Conference (ISSCC),
   pp. 22-24, 2023. DOI: 10.1109/ISSCC42615.2023.10067695

6. A 0.01 mm2 10MHz RC Frequency Reference with a 1-Point On-Chip-Trimmed Inaccuracy of 0.28% from −45°C to 125°C in 0.18μm CMOS
   An, Xiaomeng; Pan, Sining; Jiang, Hui; Makinwa, Kofi A. A.;
   In 2023 IEEE International Solid-State Circuits Conference (ISSCC),
   pp. 60-62, 2023. DOI: 10.1109/ISSCC42615.2023.10067530

7. A MEMS Coriolis-Based Mass-Flow-to-Digital Converter for Low Flow Rate Sensing
   de Oliveira, Arthur Campos; Pan, Sining; Wiegerink, Remco J.; Makinwa, Kofi A. A.;
   IEEE Journal of Solid-State Circuits,
   Volume 57, Issue 12, pp. 3681-3692, 2022. DOI: 10.1109/JSSC.2022.3210003

8. A 210 nW NPN-Based Temperature Sensor With an Inaccuracy of ±0.15 °C (3σ) From −15 °C to 85 °C Utilizing Dual-Mode Frontend
   Someya, Teruki; van Hoek, Vincent; Angevare, Jan; Pan, Sining; Makinwa, Kofi;
   IEEE Solid-State Circuits Letters,
   Volume 5, pp. 272-275, 2022. DOI: 10.1109/LSSC.2022.3222578

9. A 16 MHz CMOS RC Frequency Reference With ±90 ppm Inaccuracy From −45 °C to 85 °C
   Gürleyük, Çağrı; Pan, Sining; Makinwa, Kofi A. A.;
   IEEE Journal of Solid-State Circuits,
   Volume 57, Issue 8, pp. 2429-2437, 2022. DOI: 10.1109/JSSC.2022.3142662

10. Resistor-Based Temperature Sensors
    Pan, Sining; Makinwa, Kofi A. A.;
    Harpe, Pieter; Makinwa, Kofi A.A.; Baschirotto, Andrea (Ed.);
    Cham: Springer International Publishing, , pp. 209--230, 2022. DOI: 10.1007/978-3-030-91741-8_12
    
    Abstract: ...

    This paper presents an overview of resistor-based sensors, with a focus on their energy efficiency. First, the theoretical energy efficiency limit of resistor-based sensors is determined and compared to that of traditional BJT-based sensors. This is followed by a review of the different types of resistor-based sensors. Finally, the design of a high-resolution Wheatstone bridge sensor is discussed in detail. Read out by a continuous-time Delta-Sigma modulator, the sensor achieves state-of-the-art energy efficiency, with a resolution FoM of 10 fJ{\textperiodcentered}K2, which approaches the theoretical energy efficiency limit.

11. A MEMS Coriolis-Based Mass-Flow-to-Digital Converter with 100g/h/surdHz Noise i Floor and Zero Stability of pm 0.35mg/h
    De Oliveira, Arthur C.; Pan, Sining; Makinwa, Kofi A. A.;
    In 2022 IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 1-3, 2022. DOI: 10.1109/ISSCC42614.2022.9731704

12. A 210nW BJT-based Temperature Sensor with an Inaccuracy of ±0.15°C (3σ) from −15°C to 85°C
    Someya, Teruki; Van Hoek, Vincent; Angevare, Jan; Pan, Sining; Makinwa, Kofi;
    In 2022 IEEE Symposium on VLSI Technology and Circuits (VLSI Technology and Circuits),
    pp. 120-121, 2022. DOI: 10.1109/VLSITechnologyandCir46769.2022.9830266

13. A Self-Calibrated Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor
    S. Pan; and J. A Angevare; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    July 2021. DOI: 10.1109/JSSC.2021.3094166
    
    Abstract: ...

    This article describes a hybrid temperature sensor in which an accurate, but energy-inefficient, thermal diffusivity (TD) sensor is used to calibrate an inaccurate, but efficient, resistor-based sensor. The latter is based on silicided polysilicon resistors embedded in a Wien-bridge (WB) filter, while the former is based on an electrothermal filter (ETF) made from a p-diffusion/metal thermopile and an n-diffusion heater. The use of an on-chip sensor for calibration obviates the need for an external temperature reference and a temperature-stabilized environment, thus reducing the cost. To mitigate the area overhead of the TD sensor, it reuses the WB filter's readout circuitry. Realized in a 180-nm CMOS technology, the hybrid sensor occupies 0.2 mm². After calibration at room temperature (~25 °C) and at an elevated temperature (~85 °C), it achieves an inaccuracy of 0.25 °C (3σ) from -55 °C to 125 °C. The WB sensor dissipates 66 μ W from a 1.8-V supply and achieves a resolution of 450 μ K_rms in a 10-ms conversion time, which corresponds to a resolution figure-of-merit (FoM) of 0.13 pJ·K². The sensor also achieves a sub-10-mHz 1/f noise corner, which is comparable to that of bipolar junction transistor (BJT)-based temperature sensors.

14. A Self-Calibrated Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor
    S. Pan; and J. A Angevare; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 56, Issue 12, pp. 3551-3559, July 2021. DOI: 10.1109/JSSC.2021.3094166
    
    Abstract: ...

    This article describes a hybrid temperature sensor in which an accurate, but energy-inefficient, thermal diffusivity (TD) sensor is used to calibrate an inaccurate, but efficient, resistor-based sensor. The latter is based on silicided polysilicon resistors embedded in a Wien-bridge (WB) filter, while the former is based on an electrothermal filter (ETF) made from a p-diffusion/metal thermopile and an n-diffusion heater. The use of an on-chip sensor for calibration obviates the need for an external temperature reference and a temperature-stabilized environment, thus reducing the cost. To mitigate the area overhead of the TD sensor, it reuses the WB filter's readout circuitry. Realized in a 180-nm CMOS technology, the hybrid sensor occupies 0.2 mm². After calibration at room temperature (~25 °C) and at an elevated temperature (~85 °C), it achieves an inaccuracy of 0.25 °C (3σ) from -55 °C to 125 °C. The WB sensor dissipates 66 μ W from a 1.8-V supply and achieves a resolution of 450 μ K_rms in a 10-ms conversion time, which corresponds to a resolution figure-of-merit (FoM) of 0.13 pJ·K². The sensor also achieves a sub-10-mHz 1/f noise corner, which is comparable to that of bipolar junction transistor (BJT)-based temperature sensors.

15. A Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor with a Self-Calibrated Inaccuracy of ±0.25° C (3σ) from -55°C to 125°C
    S. Pan; and J. A Angevare; K. A. A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    February 2021. DOI: 10.1109/ISSCC42613.2021.9366032

16. A 0.14mm2 16MHz CMOS RC Frequency Reference with a 1-Point Trimmed Inaccuracy of ±400ppm from -45°C to 85°C
    H. Jiang; S. Pan; Ç. Gürleyük; K. A. A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    February 2021. DOI: 10.1109/ISSCC42613.2021.9365795

17. A 0.14mm2 16MHz CMOS RC Frequency Reference with a 1-Point Trimmed Inaccuracy of ±400ppm from -45°C to 85°C
    H. Jiang; S. Pan; Ç. Gürleyük; K. A. A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 436-438, February 2021. DOI: 10.1109/ISSCC42613.2021.9365795

18. A Hybrid Thermal-Diffusivity/Resistor-Based Temperature Sensor with a Self-Calibrated Inaccuracy of ±0.25° C (3σ) from -55°C to 125°C
    S. Pan; and J. A Angevare; K. A. A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 78-80, February 2021. DOI: 10.1109/ISSCC42613.2021.9366032

19. A 6.6-μW Wheatstone-Bridge Temperature Sensor for Biomedical Applications
    S. Pan; K. A. A. Makinwa;
    IEEE Solid-State Circuits Letters,
    Volume 3, pp. 334-337, August 2020. DOI: 10.1109/LSSC.2020.3019078
    
    Abstract: ...

    This letter presents a compact, energy-efficient, and low-power Wheatstone-bridge temperature sensor for biomedical applications. To maximize sensitivity and reduce power dissipation, the sensor employs a high-resistance (600 kΩ) bridge that consists of resistors with positive (silicided-poly) and negative (n-poly) temperature coefficients. Resistor spread is then mitigated by trimming the n -poly arms with a 12-bit DAC, which consists of a 5-bit series DAC whose LSB is trimmed by a 7-bit PWM generator. The bridge is readout by a second-order delta–sigma modulator, which dynamically balances the bridge by tuning the resistance of the silicided-poly arms via a 1-bit series DAC. As a result, the modulator’s bitstream average is an accurate and near-linear function of temperature, which does not require further correction in the digital domain. Fabricated in a 180-nm CMOS technology, the sensor occupies 0.12mm2 . After a 1-point trim, it achieves +0.2 °C/−0.1 °C (3σ) inaccuracy in a ±10 °C range around body temperature (37.5 °C). It consumes 6.6 μW from a 1.6-V supply, and achieves 200-μK resolution in a 40-ms conversion time, which corresponds to a state-of-the-art resolution FoM of 11 fJ⋅K2 . Duty cycling the sensor results in even lower average power: 700nW at 10 conversions/s.

20. A 10 fJ·K² Wheatstone Bridge Temperature Sensor With a Tail-Resistor-Linearized OTA
    S. Pan; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 56, Issue 501-510, September 2020. DOI: 10.1109/JSSC.2020.3018164
    
    Abstract: ...

    This article describes a highly energy-efficient Wheatstone bridge temperature sensor. To maximize sensitivity, the bridge is made from resistors with positive (silicided diffusion) and negative (poly) temperature coefficients. The bridge is balanced by a resistive (poly) FIR-DAC, which is part of a 2nd-order continuous-time delta-sigma modulator (CTΔ ΣM). Each stage of the modulator is based on an energy-efficient current-reuse OTA. To efficiently suppress quantization noise foldback, the 1st stage OTA employs a tail-resistor linearization scheme. Sensor accuracy is enhanced by realizing the poly arms of the bridge and the DAC from identical unit elements. Fabricated in a 180-nm CMOS technology, the sensor draws 55 μW from a 1.8-V supply and achieves a resolution of 150 μK_rms in an 8-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit (FoM) of 10 fJ·K². Furthermore, the sensor achieves an inaccuracy of ±0.4 °C (3σ) from -55 °C to 125 °C after a ratio-based one-point trim and systematic non-linearity removal, which improves to ±0.1 °C (3σ) after a 1st-order fit.

21. A 10 fJ·K² Wheatstone Bridge Temperature Sensor With a Tail-Resistor-Linearized OTA
    S. Pan; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 56, Issue 501-510, pp. 501-510, September 2020. DOI: 10.1109/JSSC.2020.3018164
    
    Abstract: ...

    This article describes a highly energy-efficient Wheatstone bridge temperature sensor. To maximize sensitivity, the bridge is made from resistors with positive (silicided diffusion) and negative (poly) temperature coefficients. The bridge is balanced by a resistive (poly) FIR-DAC, which is part of a 2nd-order continuous-time delta-sigma modulator (CTΔ ΣM). Each stage of the modulator is based on an energy-efficient current-reuse OTA. To efficiently suppress quantization noise foldback, the 1st stage OTA employs a tail-resistor linearization scheme. Sensor accuracy is enhanced by realizing the poly arms of the bridge and the DAC from identical unit elements. Fabricated in a 180-nm CMOS technology, the sensor draws 55 μW from a 1.8-V supply and achieves a resolution of 150 μK_rms in an 8-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit (FoM) of 10 fJ·K². Furthermore, the sensor achieves an inaccuracy of ±0.4 °C (3σ) from -55 °C to 125 °C after a ratio-based one-point trim and systematic non-linearity removal, which improves to ±0.1 °C (3σ) after a 1st-order fit.

22. A 6.6-μW Wheatstone-Bridge Temperature Sensor for Biomedical Applications
    S. Pan; K. A. A. Makinwa;
    IEEE Solid-State Circuits Letters,
    Volume 3, pp. 334-337, August 2020. DOI: 10.1109/LSSC.2020.3019078
    
    Abstract: ...

    This letter presents a compact, energy-efficient, and low-power Wheatstone-bridge temperature sensor for biomedical applications. To maximize sensitivity and reduce power dissipation, the sensor employs a high-resistance (600 kΩ) bridge that consists of resistors with positive (silicided-poly) and negative (n-poly) temperature coefficients. Resistor spread is then mitigated by trimming the n -poly arms with a 12-bit DAC, which consists of a 5-bit series DAC whose LSB is trimmed by a 7-bit PWM generator. The bridge is readout by a second-order delta–sigma modulator, which dynamically balances the bridge by tuning the resistance of the silicided-poly arms via a 1-bit series DAC. As a result, the modulator’s bitstream average is an accurate and near-linear function of temperature, which does not require further correction in the digital domain. Fabricated in a 180-nm CMOS technology, the sensor occupies 0.12mm2 . After a 1-point trim, it achieves +0.2 °C/−0.1 °C (3σ) inaccuracy in a ±10 °C range around body temperature (37.5 °C). It consumes 6.6 μW from a 1.6-V supply, and achieves 200-μK resolution in a 40-ms conversion time, which corresponds to a state-of-the-art resolution FoM of 11 fJ⋅K2 . Duty cycling the sensor results in even lower average power: 700nW at 10 conversions/s.

23. A CMOS Resistor-Based Temperature Sensor with a 10fJ· K2 Resolution FoM and 0.4° C (3σ) Inaccuracy From− 55°C to 125°C After a 1-point Trim
    S. Pan; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 68-70, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063064

24. A 16MHz CMOS RC Frequency Reference with±400ppm Inaccuracy from− 45° C to 85° C After Digital Linear Temperature Compensation
    Ç. Gürleyük; S. Pan; K. A. A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 64-66, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063029

25. A 16MHz CMOS RC Frequency Reference with±400ppm Inaccuracy from− 45° C to 85° C After Digital Linear Temperature Compensation
    Ç. Gürleyük; S. Pan; K. A. A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 64-66, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063029

26. A CMOS Resistor-Based Temperature Sensor with a 10fJ· K2 Resolution FoM and 0.4° C (3σ) Inaccuracy From− 55°C to 125°C After a 1-point Trim
    S. Pan; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 68-70, 2 2020. DOI: 10.1109/ISSCC19947.2020.9063064

27. A 0.12mm2 Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
    S. Pan; Ç. Gürleyük; M.F. Pimenta; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    2 2019. DOI: 10.1109/ISSCC.2019.8662457

28. A Wheatstone-Bridge Temperature Sensor with a Resolution FoM of 20fJ·K2
    S. Pan; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    2 2019. DOI: 10.1109/ISSCC.2019.8662337

29. A Wheatstone-Bridge Temperature Sensor with a Resolution FoM of 20fJ·K2
    S. Pan; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 186-188, 2 2019. DOI: 10.1109/ISSCC.2019.8662337

30. A 0.12mm2 Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
    S. Pan; Ç. Gürleyük; M.F. Pimenta; K.A.A Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 184-186, 2 2019. DOI: 10.1109/ISSCC.2019.8662457

31. A Resistor-Based Temperature Sensor with a 0.13pJ·K2 Resolution FOM
    S. Pan; Y. Luo; S.H. Shalmany; K.A.A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 1, pp. 164-173, 1 2018. DOI: 10.1109/JSSC.2017.2746671
    
    Abstract: ...

    This paper describes a high-resolution energy-efficient CMOS temperature sensor, intended for the temperature compensation of MEMS/quartz frequency references. The sensor is based on silicided poly-silicon thermistors, which are embedded in a Wien-bridge RC filter. When driven at a fixed frequency, the filter exhibits a temperature-dependent phase shift, which is digitized by an energy-efficient continuous-time phase-domain delta-sigma modulator. Implemented in a 0.18-μm CMOS technology, the sensor draws 87 μA from a 1.8 V supply and achieves a resolution of 410 μKrms in a 5-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit of 0.13 pJ·K². When packaged in ceramic, the sensor achieves an inaccuracy of 0.2 °C (3σ) from -40 °C to 85 °C after a single-point calibration and a correction for systematic nonlinearity. This can be reduced to ±0.03 °C (3σ) after a first-order fit. In addition, the sensor exhibits low 1/f noise and packaging shift.

32. A 0.25 mm2-Resistor-Based Temperature Sensor With an Inaccuracy of 0.12 °C (3σ) From −55 °C to 125 °C
    S. Pan; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 12, pp. 3347-3355, 12 2018. DOI: 10.1109/JSSC.2018.2869595
    
    Abstract: ...

    This paper describes a compact, energy efficient, resistor-based temperature sensor that can operate over a wide temperature range (-55 °C-125 °C). The sensor is based on a Wheatstone bridge (WhB) made from silicided poly-silicon and non-silicided poly-silicon resistors. To achieve both area and energy efficiencies, the current output of the WhB is digitized by a continuous-time zoom analog-to-digital converter (ADC). Implemented in a standard 180-nm CMOS technology, the sensor consumes 52 μA from a 1.8-V supply and achieves a resolution of 280 μKrms in a 5-ms conversion time. This corresponds to a state-of-the-art resolution figure-of-merit (FoM) of 40 fJ · K². After a first-order fit, the sensor achieves an inaccuracy of ±,0.12 °C (3σ) from -55 °C to 125 °C.

33. A CMOS Dual-RC Frequency Reference with ±200-ppm Inaccuracy from −45 °C to 85 °C
    Ç. Gürleyük; L. Pedalà; S. Pan; F. Sebastiano; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 12, pp. 3386-3395, 12 2018. DOI: 10.1109/JSSC.2018.2869083
    
    Abstract: ...

    This paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO’s output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from –45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.

34. A CMOS Dual-RC Frequency Reference with ±200-ppm Inaccuracy from −45 °C to 85 °C
    Ç. Gürleyük; L. Pedalà; S. Pan; F. Sebastiano; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 12, pp. 3386-3395, 12 2018. DOI: 10.1109/JSSC.2018.2869083
    
    Abstract: ...

    This paper presents a 7-MHz CMOS RC frequency reference. It consists of a frequency-locked loop in which the output frequency of a digitally controlled oscillator (DCO) is locked to the combined phase shifts of two independent RC (Wien bridge) filters, each employing resistors with complementary temperature coefficients. The filters are driven by the DCO’s output frequency and the resulting phase shifts are digitized by high-resolution phase-to-digital converters. Their outputs are then combined in the digital domain to realize a temperature-independent frequency error signal. This digitally assisted temperature compensation scheme achieves an inaccuracy of ±200 ppm from –45 °C to 85 °C after a two-point trim. The frequency reference draws 430 μA from a 1.8-V supply, while achieving a supply sensitivity of 0.18%/V and a 330-ppb Allan deviation floor in 3 s of measurement time.

35. A 0.25 mm2-Resistor-Based Temperature Sensor With an Inaccuracy of 0.12 °C (3σ) From −55 °C to 125 °C
    S. Pan; K. A. A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 12, pp. 3347-3355, 12 2018. DOI: 10.1109/JSSC.2018.2869595
    
    Abstract: ...

    This paper describes a compact, energy efficient, resistor-based temperature sensor that can operate over a wide temperature range (-55 °C-125 °C). The sensor is based on a Wheatstone bridge (WhB) made from silicided poly-silicon and non-silicided poly-silicon resistors. To achieve both area and energy efficiencies, the current output of the WhB is digitized by a continuous-time zoom analog-to-digital converter (ADC). Implemented in a standard 180-nm CMOS technology, the sensor consumes 52 μA from a 1.8-V supply and achieves a resolution of 280 μKrms in a 5-ms conversion time. This corresponds to a state-of-the-art resolution figure-of-merit (FoM) of 40 fJ · K². After a first-order fit, the sensor achieves an inaccuracy of ±,0.12 °C (3σ) from -55 °C to 125 °C.

36. A Resistor-Based Temperature Sensor with a 0.13pJ·K2 Resolution FOM
    S. Pan; Y. Luo; S.H. Shalmany; K.A.A. Makinwa;
    IEEE Journal of Solid-State Circuits,
    Volume 53, Issue 1, pp. 164-173, 1 2018. DOI: 10.1109/JSSC.2017.2746671
    
    Abstract: ...

    This paper describes a high-resolution energy-efficient CMOS temperature sensor, intended for the temperature compensation of MEMS/quartz frequency references. The sensor is based on silicided poly-silicon thermistors, which are embedded in a Wien-bridge RC filter. When driven at a fixed frequency, the filter exhibits a temperature-dependent phase shift, which is digitized by an energy-efficient continuous-time phase-domain delta-sigma modulator. Implemented in a 0.18-μm CMOS technology, the sensor draws 87 μA from a 1.8 V supply and achieves a resolution of 410 μKrms in a 5-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit of 0.13 pJ·K². When packaged in ceramic, the sensor achieves an inaccuracy of 0.2 °C (3σ) from -40 °C to 85 °C after a single-point calibration and a correction for systematic nonlinearity. This can be reduced to ±0.03 °C (3σ) after a first-order fit. In addition, the sensor exhibits low 1/f noise and packaging shift.

37. A 0.25mm2 resistor-based temperature sensor with an inaccuracy of 0.12°C (3σ) from −55°C to 125°C and a resolution FOM of 32fJK2
    S. Pan; K.A.A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 320 - 322, 2 2018. DOI: 10.1109/ISSCC.2018.8310313

38. A 0.25mm2 resistor-based temperature sensor with an inaccuracy of 0.12°C (3σ) from −55°C to 125°C and a resolution FOM of 32fJK2
    S. Pan; K.A.A. Makinwa;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 320 - 322, 2 2018. DOI: 10.1109/ISSCC.2018.8310313

39. Energy-Efficient High-Resolution Resistor-Based Temperature Sensors
    S. Pan; K.A.A. Makinwa;
    Springer, Chapter Hybrid ADCs, Sm, , 2017.

40. Optimum Synchronous Phase Detection and its Application in Smart Sensor Interfaces
    S. Pan; K.A.A. Makinwa;
    In IEEE International Symposium on Circuits and Systems (ISCAS),
    June 2017. DOI: 10.1109/iscas.2017.8050417

41. Energy-Efficient High-Resolution Resistor-Based Temperature Sensors
    S. Pan; K.A.A. Makinwa;
    In Proc. Advances in Analog Circuit Design Workshop (AACD),
    April 2017. DOI: 10.1007/978-3-319-61285-0_10

42. A Frequency-Locked Loop Based on an Oxide Electrothermal Filter in Standard CMOS
    L. Pedala; C. Gurleyuk; S. Pan; F. Sebastiano; K. Makinwa;
    In European Solid-State Circuits Conference (ESSCIRC),
    Leuven, Belgium, 9 2017. DOI: 10.1109/esscirc.2017.8094512

43. A CMOS Temperature Sensor with a 49fJ·K2 Resolution FoM
    S. Pan; H. Jiang; K.A.A. Makinwa;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    6 2017. DOI: 10.23919/vlsic.2017.8008557

44. A Resistor-Based Temperature Sensor with a 0.13pJ·K2 Resolution FOM
    S. Pan; Y. Luo; S.H. Shalmany; K.A.A. Makinwa;
    In IEEE International Solid-State Circuits Conference (ISSCC),
    February 2017. DOI: 10.1109/jssc.2017.2746671

45. A resistor-based temperature sensor with a 0.13pJ·K2 resolution FOM
    Pan, Sining; Luo, Yanquan; Shalmany, Saleh Heidary; Makinwa, Kofi A. A.;
    In 2017 IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 158-159, 2017. DOI: 10.1109/ISSCC.2017.7870309

46. A Frequency-Locked Loop Based on an Oxide Electrothermal Filter in Standard CMOS
    L. Pedala; C. Gurleyuk; S. Pan; F. Sebastiano; K. Makinwa;
    In European Solid-State Circuits Conference (ESSCIRC),
    Leuven, Belgium, pp. 7-10, 9 2017. DOI: 10.1109/esscirc.2017.8094512

47. A CMOS Temperature Sensor with a 49fJ·K2 Resolution FoM
    S. Pan; H. Jiang; K.A.A. Makinwa;
    In Dig. Techn. Paper IEEE Symposium on VLSI Circuits (VLSI),
    pp. C82-C83, 6 2017. DOI: 10.23919/vlsic.2017.8008557

48. Optimum Synchronous Phase Detection and its Application in Smart Sensor Interfaces
    S. Pan; K.A.A. Makinwa;
    In IEEE International Symposium on Circuits and Systems (ISCAS),
    pp. 1-4, June 2017. DOI: 10.1109/iscas.2017.8050417

49. Energy-Efficient High-Resolution Resistor-Based Temperature Sensors
    S. Pan; K.A.A. Makinwa;
    In Harpe, Pieter; Makinwa, Kofi A. A.; Baschirotto, Andrea (Ed.), Proc. Advances in Analog Circuit Design Workshop (AACD),
    Cham, Springer International Publishing, pp. 183--200, April 2017. DOI: 10.1007/978-3-319-61285-0_10
    
    Abstract: ...

    This paper presents two high-resolution CMOS temperature sensors intended for the temperature compensation of MEMS/quartz frequency references. One is based on a Wien bridge RC filter, which outputs a temperature-dependent phase shift when driven by a stable frequency; the other is based on a Wheatstone bridge, which outputs a temperature-dependent current. The bridge outputs are digitized by energy-efficient continuous-time delta-sigma modulators. Two prototypes were fabricated in a standard 0.18 $\mu$m CMOS technology. Both dissipate less than 200 $\mu$W and achieve sub-mK resolution, as well as sub-0.2pJ{\textperiodcentered}K2 resolution FoMs, which corresponds to state-of-the-art energy efficiency.

50. A high-resolution resistor-based temperature sensor
    S. Pan;
    MSc thesis, Delft University of Technology, Aug 2016. cum laude.

BibTeX support