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From: Spehro Pefhany
Subject: Re: current source for array of infrared leds
References: <firstname.lastname@example.org> <email@example.com>
X-Newsreader: Forte Agent 1.92/32.572
Date: Mon, 02 Dec 2002 17:42:24 GMT
NNTP-Posting-Date: Mon, 02 Dec 2002 12:42:24 EST
On Mon, 2 Dec 2002 08:53:18 -0800, the renowned "Harry Dellamano"
> Now the question is, how do we set the voltage to control LED current over
>wide ranges of temperatures for constant light intensities?
There are at least two requirements to call this a temperature
1) Light intensity at nominal die temperature (most important)
2) Light intensity at one other die temperature
You are not free to set the voltage to achieve nominally zero tempco
between the two points (if it is possible), as getting the nominal
light level right is paramount. You obviously need two degrees of
freedom to be able to set the two independently.
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