PWM digital pixel sensor based on asynchronous self-resetting scheme

Alistair Kitchen, Amine Bermak, Abdesselam Bouzerdoum

Research output: Contribution to journalArticle

42 Citations (Scopus)


In this letter, a pulse-width modulated digital pixel sensor is presented along with its inherent advantages such as low power consumption and wide operating range. The pixel, which comprises an analog processor and an 8-bit memory cell, operates in an asynchronous self-resetting mode. In contrast to most CMOS image sensors, in our approach, the photocurrent signal is encoded as a pulse-width signal, and converted to an 8-bit digital code using a Gray counter. The dynamic range of the pixel can be adapted by simply modulating the clock frequency of the counter. To test the operation of the proposed pixel architecture, an image sensor array has been designed and fabricated in a 0.35-μm CMOS technology, where each pixel occupies an area of 45 × 45 μm2. Here, the operation of the sensor is demonstrated through experimental results.

Original languageEnglish
Pages (from-to)471-473
Number of pages3
JournalIEEE Electron Device Letters
Issue number7
Publication statusPublished - Jul 2004
Externally publishedYes


ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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