Infrared photodiode and photodiode

Discussion in 'General Electronics Chat' started by bug13, May 16, 2013.

  1. bug13

    Thread Starter Well-Known Member

    Feb 13, 2012
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    Hi guys

    I got a silly question, are infrared photodiode and photodiode the same thing? I got photodiode but it looks like an infrared photodiode.

    Because it looks like a LED with dard red/black casing.

    Hope I am making sense.
     
  2. Meixner

    Member

    Sep 26, 2011
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    Yes they are the same.
     
  3. timescope

    Member

    Dec 14, 2011
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    Which is like saying a Ford and Mercedes-Benz are the same: they are both cars.

    An infrared photo diode is designed to work in the infrared part of the electromagnetic spectrum. The spectral characteristics depend on the material used to fabricate them:

    https://en.wikipedia.org/wiki/Photodiode

    Timescope
     
    Last edited: May 17, 2013
  4. bertus

    Administrator

    Apr 5, 2008
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  5. Markd77

    Senior Member

    Sep 7, 2009
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    Inside they are the same thing, but the dark casing is to filter out most of the visible light.
     
  6. Meixner

    Member

    Sep 26, 2011
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    Yes but they all peak in the infrared region.
     
  7. timescope

    Member

    Dec 14, 2011
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    Not all peak in the infrared region of 700nm to 1mm, for example the Sharp BS120 peaks at 560nm and is characterised for visible light.

    Timescope
     
  8. bug13

    Thread Starter Well-Known Member

    Feb 13, 2012
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    So if I want to make a proximity sensor out of infrared led and infrared photodiode, I will need a matching wavelength pare?
     
  9. timescope

    Member

    Dec 14, 2011
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    A matched pair would give the best results.

    Something like this

    Timescope
     
    Last edited: May 18, 2013
  10. Meixner

    Member

    Sep 26, 2011
    116
    21
    Without a part number to go by, chances are the photodiode he has is infrared. As are 99.99% of photodiodes.
     
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