A CMOS-Imager-Pixel-Based Temperature Sensor for Dark Current Compensation

Research output: Contribution to journalArticleScientificpeer-review

40 Downloads (Pure)

Abstract

This brief proposes employing each of the classical 4 transistor (4T) pinned photodiode (PPD) CMOS image sensor (CIS) pixels, for both imaging and temperature measurement, intended for compensating the CISs' dark current, and dark signal non-uniformity (DSNU). The proposed temperature sensors rely on the thermal behavior of MOSFETs working in subthreshold region, when biased with ratiometric currents sequentially. Without incurring any additional hardware or penalty to the CIS, they are measured to have thermal curvature errors less than ±0.3 °C and 3sigma process variations within ±1.3 °C, from 108 sensors on 4 chips, over a temperature range from -20 °C to 80 °C. Each of them consumes 576 nJ/conversion at a conversion rate of 62 samples/s, when quantized by 1 st-order 14 bit delta-sigma ADCs and fabricated using 0.18mu text{m} CIS technology. Experimental results show that they facilitate digital compensation for average dark current and DSNU by 78% and 20%, respectively.

Original languageEnglish
Article number8704909
Pages (from-to)255 - 259
Number of pages5
JournalIEEE Transactions on Circuits and Systems II: Express Briefs
Volume67
Issue number2
DOIs
Publication statusPublished - 2020

Keywords

  • Temperature sensors
  • Temperature measurement
  • Calibration
  • Dark current
  • Semiconductor device measurement
  • delta-sigma (Delta-sigma) modulator
  • CMOS image sensor (CIS)
  • temperature compensation
  • dark current
  • DSNU
  • delta-sigma (Δ-σ) modulator

Fingerprint Dive into the research topics of 'A CMOS-Imager-Pixel-Based Temperature Sensor for Dark Current Compensation'. Together they form a unique fingerprint.

  • Cite this