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A Sensitive Electronic Photoreceptor

Mead, Carver (1985) A Sensitive Electronic Photoreceptor. In: 1985 Chapel Hill Conference on Very Large Scale Integration. Computer Science Press , Rockville, MD, pp. 463-471. ISBN 0881751030.

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The photoreceptors in biological systems give meaningful outputs over about six orders of magnitude of illumination intensity. If we are to build an electronic vision system that is truly useful, it must have a similar dynamic range. The elements of an electronic receptor with many orders of magnitude dynamic range are described below. Experimental devices were fabricated in p-well cMOS bulk technology through the MOSIS foundry; npn phototransistors with collector connected to substrate are a byproduct of this process. The n-type bulk forms the collector, the p-well is the base, and the n+ diffusion the emitter. In a typical process, a large transistor of this sort has a current gain β of more than a thousand. Smaller transistors have lower current gains, but are still respectable. The key to very sensitive receptors is to use the current gain of this very clean bipolar transistor before subjecting the signal to any noise from subsequent amplification stages.

Item Type:Book Section
Additional Information:© 1985 Computer Science Press. Thanks are due David Feinstein for his careful and perceptive review of the manuscript, and to John Tanner and MaryAnn Maher for many helpful discussions. This work was supported by the System Development Foundation.
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System Development FoundationUNSPECIFIED
Record Number:CaltechAUTHORS:20150310-153332443
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:55688
Deposited On:11 Mar 2015 05:37
Last Modified:22 Feb 2022 18:01

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