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Looking for a high current darlington transistor.

Discussion in 'General Electronics Discussion' started by sureshot, Jul 20, 2017.

  1. sureshot

    sureshot

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    Jul 7, 2012
    Basically as the title says, does anyone know of a high gain hfe high collector current pnp transistor. I'm looking for a flat style package like the T03P case. The best i can find is a TIP147, I was hoping to find a transistor like above with a hfe between 750 and 1000 preferably a darlington. And a collector current of around 20 to 30 Amps. Its for a series pass transistor, i can find T03 style packages with this specified above, but not much in a T03P style flat package. Thanks for reading, any thoughts appreciated.
     
  2. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    You can make your own Darlington buy adding another lower power transistor which is just used to supply the base voltage and current to the higher power transistor. Maybe not as good as a true Darlington in one package, you will have to try it.
    Cheers
    Adam
     
  3. dorke

    dorke

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    The MJH6287 could be a candidate.
    Is the darlington the only solution for you?power-mosfet?
     
  4. sureshot

    sureshot

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    Thanks for your replys, yes I knew about the two transistor darlington, but prefer a single component solution. It's for mounting 4 x transistors to a 100 watt cpu heatsink with fan. As a project for mounting and potting to a single large heatsink, then potting it, as it's outside of the case. I'd never thought about mosfets, think I should look into this..
    I'm not sure if they can be used as a series pass element for high current low voltage. I can find usable T03 darlington transistors, but nothing with greater collector current than 10 Amps of the TIP147. I will certainly look into mosfets. Thanks for your help.
     
  5. BobK

    BobK

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    When you say pass transistor, do you mean it will be in linear mode, as in a vpltage regulator, or is it simply an on/off switch?

    If it is the latter, a MOSFET is far better as there are some that can pass 20 amps without even needing a heat sink.

    Bob
     
  6. BobK

    BobK

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    Jan 5, 2010
    Here for instance. Current handling 180A On resistance 2.4mΩ. At 20A this would dissipate 48mW, it would not even get warm!

    This only applies though if it will be all ON or all OFF. If linear operation is needed, MOSFETS do not have such an advantage over bipolar transistors unless it will be dropping less than the saturation voltage of the bipolar transistor.

    https://www.digikey.com/product-det...04P4L02ATMA1/IPB180P04P4L02ATMA1TR-ND/5413673

    Bob
     
  7. sureshot

    sureshot

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    Jul 7, 2012
    Thanks Bob, it would be for linear pass transistor use, not a switch sinario. A look around the Web only threw up one article I could find, link below. So I guess BJT's are better in this application. I might try the mosfet circuit in the link, I'm curious to see how it behaves.

    http://www.homemade-circuits.com/2015/12/lm317-with-outboard-current-boost.html
     
  8. kellys_eye

    kellys_eye

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    Jun 25, 2010
  9. sureshot

    sureshot

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    Jul 7, 2012
    Thank you for the link, i didn't think just darlington transistor as a search term was enough to narrow down a high current component. I will give it a go, thanks.
     
  10. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    When you choose a transistor, be very sure to carefully read the specs. Maximum voltage and current can't be achieved together, the maximum power dissipation can often not be maintained indefinitely without exotic heatsinking, and beware of secondary breakdown.
     
  11. sureshot

    sureshot

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    Jul 7, 2012
    Thanks Steve, i'm slowly getting my head round transistor specs.
     
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