A vision sensor with on-pixel ADC and in-built light adaptation mechanism

Amine Bermak, Abdessellam Bouzerdoum, Kamran Eshraghian

Research output: Contribution to journalArticle

25 Citations (Scopus)


In this paper we propose an on-pixel Analogue-to-Digital Converter (ADC) based on pulse frequency modulation (PFM) scheme. This PFM based converter presents a viable solution for pixel-level based ADC. It uses a simple and robust circuit that can be implemented in a compact area resulting in a 23% fill-factor for a digital vision sensor in 0.25 μm CMOS technology. An in-built light adaptation mechanism has also been implemented which allows the sensor to better adapt to low-light intensity or to adjust the sensor saturation level. As a consequence, the proposed sensor features a programmable dynamic range. Image lag is eliminated since a reset of the photodetector is performed after the conversion period. A prototype comprising a 32 × 32 pixel array has been implemented in CMOS 0.25 μm technology. Each pixel occupies an area of 45 × 45 μm2 with an average power consumption of 85 μW per pixel.

Original languageEnglish
Pages (from-to)1091-1096
Number of pages6
JournalMicroelectronics Journal
Issue number12
Publication statusPublished - 1 Dec 2002



  • CMOS imagers
  • CMOS vision sensors
  • Light adaptation
  • Pulse frequency modulation
  • VLSI

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering

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