LTV-4N35

Discussion in 'General Electronics Chat' started by banzai, Nov 5, 2014.

  1. banzai

    Thread Starter Member

    Jan 3, 2014
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    Hi guys

    Going trough the data sheet for the LTV-4N35 i can't find any information about pin 6.
    I have not used photocouplers before so i kind of only knows the basics on them. From the diagram on the data sheet, i can see that the output side looks like a transistor with pin 6 being the base terminal ???, and of cource the transistor kicks also in when it sees the light from the LED inside. So the question is why is there no beta rating for pin 6 ?.
     
  2. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,124
    266
    The base of the photo transistor is rarely used, most of the time it's either not present, not connected, or tied to ground through a resistor to prevent it from floating around.

    One is usually only interested in the photo current, additional bias is not relevant.
     
  3. banzai

    Thread Starter Member

    Jan 3, 2014
    71
    0
    then why do they provide the pin and not mention any information about it. Assume i want to use it, how would i know what current i need to provide to it ?
     
  4. Sensacell

    Well-Known Member

    Jun 19, 2012
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    They really assume your are not going to use the base lead, what would your idea be for how to use it? Assuming that there was appropriate documentation?
     
  5. banzai

    Thread Starter Member

    Jan 3, 2014
    71
    0
    well i don't have any thing in mind but in case one wanted to use it where should one head for information regarding the base ?
     
  6. ericgibbs

    Senior Member

    Jan 29, 2010
    2,499
    380
    hi banzai,
    Read thru this pdf for use of pin 6 [ Base pin]
    E
     
  7. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,124
    266
    Interesting! base resistor to ground substantially improves the response time- turning off! I had no idea, always just ignored the base connection.
     
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