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Are hybrid parameters useful for design?

Discussion in 'Electronic Design' started by Rajib Kumar Bandopadhyay, Oct 13, 2012.

  1. Can I have the current picture in the developed countries on h-
    parameters? I believe, with so much computing power at their hands,
    people should not use h-parameters nowadays. They have no reason to. In
    case of complex circuitry, you could do simulations, and in practice, you
    use ICs in place of transistors. what is your experience with hybrid
    parameters? Could you discuss this with people in the univ. laboratories?

    I would mention an important aspect which intrigued me
    while I was studying in Univ. The theory books put so much emphasis on
    hybrid parameters, but to me, they are good for later analysis, i.e.,
    not to invent something new, but when invented, they try to find how
    the system work, not for learning electronics principles. And also, in the
    practical world I did not come across specific cases of using
    h-parameters. I thought - such wastage of time and effort!
     
  2. John S

    John S Guest

    I must disagree with you, John. I know you have heard of hfe. And, I
    still have numerous modern data sheets with such things as hre, etc.

    John
     
  3. John S

    John S Guest

    So what, John?

    Allow me to cut and paste your response above (maybe because you have
    reading comprehension problems):

    You say that they are not on transistor data sheets and you are wrong.
    THAT was the essential reason for my reply; not all your other verbiage.

    No. So what? Are you just trying to pick an argument? Did you READ what
    I wrote?
    I don't give a s**t and SO WHAT?. LOOK AT WHAT I POSTED!!! I am
    beginning to believe that others on this group are correct. All you want
    to do is argue. This is another of your attempts to move the target with
    a lame attempt to put the ball in your court.

    F**CK YOU, DIPSH**T.

    John S
     
  4. miso

    miso Guest

    I can't imagine any educated engineer not doing back of the envelope
    design on discrete devices, even if it is just a simple gm*ro to
    estimate the gain of a stage, gmC for bandwidth, etc. But there are
    plenty of clueless engineers out there that just plop stuff down in spice.

    If you are selling moderate performance boards by the hundreds, then
    just how optimal do you need to be? If you are selling chips by the
    hundreds of thousands, then it is a different story. In analog chip
    design, you need to meet the spec over mil temp at the minimum power. If
    you don't, somebody else will.
     
  5. Guest

    How could you possibly have missed them on the 2N3904 datasheet??? Do you even look at the datasheet? They're on bunches of others, mostly older, too.

    The most popular transistor model is hybrid-pi, hands down. Usually as a first approximation prior to simulation, a geometric mean of small signal parameters at the corners of region of operation is sufficient for preliminary performance estimation.
    Please cease and desist presuming to speak for how things are done in America. Mnay people have heartburn with your methods.
     
  6. legg

    legg Guest

    It's just one way of looking at things. The discipline is probably not
    wasted.

    http://www.rfcafe.com/references/electrical/s-h-y-z.htm

    RL
     
  7. Guest

    Yes, but not "electronical"- too boring. And didn't I espouse hybrid-pi? That is not h-parameter. All that h- y- g- and who knows what else was a force fit into two-port network theory of the time.
     
  8. India has a tradition of excellent rote-learners. The earlier tradition
    of rote-learning verses to impress others (to rise in social rank) is
    replaced by the slavish solving of complex mathematical problems of no
    originality. There is no love for one's field, only ambition to be better
    off than the rest. That is why, you get brilliant engineering students
    from the IITs ending up in management, banking and finance. The country
    does not have appreciable input in well-cited peer-reviewed scientific
    papers. Patents are minuscule. Meritocracy is absent, so meritorious
    Indians run away abroad and try never to come back. I have seen the
    academia from up close, and the lesser said the better...
     
  9. My precise question was not about learning, but about actual use of, the
    h-parameters.
    As JL says:

    h-parameters are a subset of the entire analysis thing. We must restrict
    ourselves to discussing about h-parameters
     
  10. Why are you and personally attacking JL.
    He has stated a point, but I did not feel he wanted to pick up an
    argument!
    Please, I sought your, and others', help with information. Please let
    them help me with the information they can provide, which they believe is
    correct. It is his personal belief. You state your point and stand back
    and let someone else say his.
     
  11. Please do elaborate your statement. I am a little dimwit.
    I saw the page, but it is just another page, but probably has couple of
    citations, which makes it worthwhile:
    1. IEEE Transactions on Microwave Theory and Techniques. Vol 42, No 2.
    February 1994. Conversions Between S, Z, Y, h, ABCD, and T Parameters
    which are Valid for Complex Source and Load Impedances. By Dean A.
    Frickey, Member, IEEE

    2. IEEE Transactions on Microwave Theory and Techniques. Vol 43, No 4.
    April 1995. A correction was printed by Roger B. Marks and Dylan F.
    Williams.

    JL said so, that other than small-signal RF operations h-parameters are
    not very useful. And there are so many parameters, people are bound to be
    confused!
    I must thank you for all the trouble you took to post the information.
    My regards.
     
  12. Guest

    Apparently you fell asleep in civics class too, because India is a paradigmof meritocracy and not its absence. Meritocracy is a political term which describes the selection process for administration positions as being based on standardized test screening, aka civil service examinations, versus personal and/or political party affiliation.
     
  13. Guest

    Do you ever use transistors for anything other than non-critical switching, current sources and buffers?
     
  14. Guest

    You're still not getting it through your thick skull that the classic two-port h-parameters are NOT hybrid pi.
     
  15. John S

    John S Guest

    I read your response as "They are not on transistor data sheets." Is hfe
    an h-parameter? Can you at least admit that hfe is on most data sheets?
    All I have said is that you are wrong.

    You did not (in earlier posts). If I am wrong, please show me where.

    I did not say that h-parameters are useful. I did not say that I use
    them. I did not say that any other person uses them.

    I don't care about whether you like them, or use them, or any of your
    other excuses to avoid the fact that your statement "They are not on
    transistor data sheets" is inaccurate. At least hfe is there. There are
    other, low level bipolar transistor, data sheet which still have
    h-parameters.

    Why can't you accept that?
     
  16. John S

    John S Guest

    Do you think *you* do?
     
  17. John S

    John S Guest

    Please show the post where you asked that question.
     
  18. John S

    John S Guest

    What does that have to do with your original statement "They are not on
    transistor data sheets" ?

    Back peddling now, eh?
    And you wonder why?
     
  19. Guest

    I know more about the meaning of meritocracy than he does, that's for sure.And claiming to know "more" than him is nearly vaccuous as he seems disturbed- if he's even Indian, or maybe just some f'ing troll from some Anglo waste dump somewhere.
     
  20. Guest

    The very word has its origins in government administration and not non-governmental professions. How damned dumb are you? Here's a brief overview evenyou should be able to understand, unless you question the authority of OPM:
    http://www.opm.gov/perform/articles/054.asp
     
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