Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!mips!sgi!rpw3@rigden.wpd.sgi.com
From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Newsgroups: sci.electronics
Subject: Re: LED refresh rate
Message-ID: <61580@sgi.sgi.com>
Date: 5 Jun 90 09:24:19 GMT
References: <30513@cup.portal.com>
Sender: news@sgi.sgi.com
Reply-To: rpw3@sgi.com (Rob Warnock)
Distribution: usa
Organization: Silicon Graphics, Inc., Mountain View, CA
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In article <30513@cup.portal.com> John_A_Pham@cup.portal.com writes:
+---------------
| Can someone tell me what is the average time for a LED to fully lit
| and vice-versa?  I remember it is around 3Khz or was it 300Khz?
+---------------

It depends on the LED, but more on the driving ciruits. I have driven
the red LEDs in H-P low-cost plastic fiber-optic cables at 10 MHz and
above. The 1300nm LEDs in FDDI controllers run at 125 megabaud (100 Mb/s
of 4/5 coding). Even dirt cheap LEDs can be run at several megahertz.

Of course, good luck trying to build a dirt cheap *detector*...  ;-}


-Rob

-----
Rob Warnock, MS-9U/510		rpw3@sgi.com		rpw3@pei.com
Silicon Graphics, Inc.		(415)335-1673		Protocol Engines, Inc.
2011 N. Shoreline Blvd.
Mountain View, CA  94039-7311