Help finding the right transistor.

Discussion in 'General Electronics Chat' started by masteropie, Feb 7, 2009.

  1. masteropie

    Thread Starter Member

    May 17, 2008
    26
    0
    I have been browsing various sites today trying to find the best transistor for a project. Fairchild is down, i really like their product browser :( I am looking for a switch transistor. Anywhere from 10Vds to 100Vds and from 10mAds to 500mAds. Also under 5nA leakage at room temp. The faster the better.

    The best i have found so far is the PN5432 JFET:
    25Vds
    150mAds
    1nS Rise
    30nS Fall
    200pA Leakage

    I don't like the 30nS fall time, 5nS would be nice. I was hoping for surface mount as well.

    I would appreciate a push in the right direction. Thanks!
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Try a search in Digikey, Farnel, RS, etc
     
  3. masteropie

    Thread Starter Member

    May 17, 2008
    26
    0
    Ya i have spent quite some time browning mouser. The problem is they don't list leakage.
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    You can look at the datasheet of the MOS your interested in.
     
  5. masteropie

    Thread Starter Member

    May 17, 2008
    26
    0
    Ya, i looked at at least a hundred today. I was wondering if there was a better way. Most datasheets don't have both leakage and rise/fall times anyways, since they are not important in most applications.
     
  6. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    What is your application?
     
  7. masteropie

    Thread Starter Member

    May 17, 2008
    26
    0
    A discrete 24bit DAC. Its pretty simple, just 24 transistors and resistors.
     
  8. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    You will be lucky to build a binary-input DAC with 10 bit accuracy and linearity using discrete parts. You can still build a 24 bit DAC, but it won't perform better than a 10 bit one.
     
  9. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    RonH is right. Real components have value tolerance, their characteristics change with temperature and so on. It would be better you buy a chip for this job. Why do you need such high resolution?
     
Loading...