Alt-BEAM Archive
Message #10296
To: beam@sgiblab.sgi.com
From: Sathe Dilip sathe_dilip@bah.com
Date: Wed, 16 Feb 2000 14:57:29 -0500
Subject: Re: pdiode ptransistor?
> It's not that simple. A photo transistor, when its base is properly
> biased, can give you some current (induced by photons/light in this
> case) amplification. A photo diode will just give you the increase in
> leakage current when exposed to light. Getting the first stage of
> amplification right at the source is important when you are dealing with
> low noise requirements in a circuit. In BEAM environment where usually
> we are using the sensor to give us a presence/absence of light type of
> indication, this may not matter that much. But say you want to build a
> light beam communicator, and you will see the need for a low noise input
> stage.
>
> Dilip
> --------------------------------------
>
> Dane Gardner wrote:
> >
> > Actually a transistor is two diodes back to back.
>
> SNIP
> ----------------------------------------------------------------------
> The early bird may get the worm, but the second mouse gets the cheese.
> ----------------------------------------------------------------------
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