Digital pixel sensor array with logarithmic delta-sigma architecture

Sensors (Basel). 2013 Aug 16;13(8):10765-82. doi: 10.3390/s130810765.

Abstract

Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs). To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC) in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS) technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analog-Digital Conversion*
  • Biomimetics / instrumentation*
  • Computer-Aided Design
  • Equipment Design
  • Equipment Failure Analysis
  • Humans
  • Ocular Physiological Phenomena*
  • Photography / instrumentation*
  • Semiconductors*
  • Signal Processing, Computer-Assisted / instrumentation*
  • Transducers*