Compact Thermal-Diffusivity-Based Temperature Sensors in 40-nm CMOS for SoC Thermal Monitoring

Research output: Contribution to journalArticleScientificpeer-review

29 Citations (Scopus)
35 Downloads (Pure)


An array of temperature sensors based on the thermal diffusivity (TD) of bulk silicon has been realized in a standard 40-nm CMOS process. In each TD sensor, a highly digital voltage-controlled oscillator-based Σ Δ ADC digitizes the temperature-dependent phase shift of an electrothermal filter (ETF). A phase calibration scheme is used to cancel the ADC's phase offset. Two types of ETF were realized, one optimized for accuracy and one optimized for resolution. Sensors based on the accuracy-optimized ETF achieved a resolution of 0.36 °C (rms) at 1 kSa/s, and inaccuracies of ±1.4 °C (3 Σ , uncalibrated) and ±0.75 °C (3 Σ, room-temperature calibrated) from -40 °C to 125 °C. Sensors based on the resolution-optimized ETFs achieved an improved resolution of 0.21 °C (rms), and inaccuracies of ±2.3 °C (3 Σ, uncalibrated) and ±1.05 °C (3 Σ, room-temperature calibrated). The sensors draw 2.8 mA from supply voltages as low as 0.9 V, and occupy only 1650 μ m2 , making them some of the smallest smart temperature sensors reported to date, and well suited for thermal monitoring applications in systems-on-chip.

Original languageEnglish
Article number7835088
Pages (from-to)834-843
Number of pages10
JournalIEEE Journal of Solid State Circuits
Issue number3
Publication statusPublished - 2017

Bibliographical note

Accepted Author Manuscript


  • Phase-to-digital converter
  • temperature sensors
  • thermal diffusivity (TD)
  • thermal monitoring
  • voltage-controlled oscillator (VCO)-based sigma-delta modulator


Dive into the research topics of 'Compact Thermal-Diffusivity-Based Temperature Sensors in 40-nm CMOS for SoC Thermal Monitoring'. Together they form a unique fingerprint.

Cite this