F.E.T pin outs on a schematic

Discussion in 'Analog & Mixed-Signal Design' started by Fluxor1964, Apr 29, 2017.

  1. Fluxor1964

    Thread Starter Member

    Jun 11, 2015
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    I am attempting to lay out a schematic onto veroboard, this is my first time using F.E.T transistors and looking at the circuit, I don't know what pins are what....... I have the pin out for the 2N5951 but although the gate is clear to see, the other two connections look identical, I don't know which is the source and which is the drain according to the schematic I am following.

    Neil.
     
  2. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    Unless we are to guess, you'd better attach the schematic.
     
  3. Fluxor1964

    Thread Starter Member

    Jun 11, 2015
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    You are to guess ;-)
     
  4. crutschow

    Expert

    Mar 14, 2008
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    The it's the left one. :rolleyes:
     
  5. Fluxor1964

    Thread Starter Member

    Jun 11, 2015
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    Are you sure?.....i don't want it to smoke :confused:
     
  6. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    The pinout is given here.
     
  7. Fluxor1964

    Thread Starter Member

    Jun 11, 2015
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    Yes as I said...i already have the pin out, my issue is that on the schematic, the gate is the only pin that is Identifiable being the one with the arrow on it, the other pins either side look identical, one going to ground via a resistor and the other directly connected to the positive supply.
     
  8. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    The one connected to the positive supply is the drain.
    I'll leave you with the process of elimination.
     
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  9. Fluxor1964

    Thread Starter Member

    Jun 11, 2015
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    Good job I asked, I assumed.that to be the source :eek:....

    Thanks for your help guys.

    Neil.
     
  10. ian field

    AAC Fanatic!

    Oct 27, 2012
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    Some JFETs are symmetrical and work with D/S either way round - but don't count on it without checking the data sheet.

    Some manufacturers get confused about pin layouts on second sourced parts - I don't know any easy way to tell for sure with a JFET. It may work better one way round than the other. Usually the gate is in the wrong position - that's a little easier to figure out.

    Some parts have a suffix letter - sometimes that suffix indicates an alternative pin layout.
     
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