Departmental Papers (BE)

Document Type

Journal Article

Date of this Version

February 2003


An arbitrated address-event imager has been designed and fabricated in a 0.6-μm CMOS process. The imager is composed of 80 x 60 pixels of 32 x 30 μm. The value of the light intensity collected by each photosensitive element is inversely proportional to the pixel’s interspike time interval. The readout of each spike is initiated by the individual pixel; therefore, the available output bandwidth is allocated according to pixel output demand. This encoding of light intensities favors brighter pixels, equalizes the number of integrated photons across light intensity, and minimizes power consumption. Tests conducted on the imager showed a large output dynamic range of 180 dB (under bright local illumination) for an individual pixel. The array, on the other hand, produced a dynamic range of 120 dB (under uniform bright illumination and when no lower bound was placed on the update rate per pixel). The dynamic range is 48.9 dB value at 30-pixel updates/s. Power consumption is 3.4 mW in uniform indoor light and a mean event rate of 200 kHz, which updates each pixel 41.6 times per second. The imager is capable of updating each pixel 8.3K times per second (under bright local illumination).


Copyright 2003 IEEE. Reprinted from IEEE Journal of Solid-State Circuits, Volume 38, Issue 2, February 2003, pages 281-294.
Publisher URL:

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it.


arbitrated, address event, digital image sensor, high dynamic range, low-power imager



Date Posted: 10 November 2004

This document has been peer reviewed.