Any spice model for 6n139 optocoupler ?

Discussion in 'General Electronics Chat' started by Nik, May 20, 2006.

  1. Nik

    Thread Starter Well-Known Member

    May 20, 2006
    55
    3
    Hi, anyone have a link to a workable spice model for 6N139 optocoupler ?

    A basic coupler's LED drives a photo-tranny: 6N139 has a fast photo-diode detector and split-darlington amp with base access for sensitivity / bandwidth trade-off...

    Sadly, the usual libraries seem to lack any coupler with diode detectors, never mind a 'similar' split darlington.

    I've googled extensively, searched manufacturers' sites and documents, drawn blank. Unfortunately, I do not have access to the 'graph-to-model' tools found in some spice versions.

    ( This is not a college / assignment query. )
     
  2. CoulombMagician

    Active Member

    Jan 10, 2006
    37
    0
    Yes, right there in spice. You can make your own model using the generic diode and transistor models and a current controlled current source. Use the diode current as the control current and feed the controlled current into the base of the transistor. Try the intusoft website, they have an app note describing this.
     
  3. perteq

    New Member

    May 23, 2006
    1
    0
    ()()
     
  4. Nik

    Thread Starter Well-Known Member

    May 20, 2006
    55
    3
    Thanks, CM, I had that AppNote, but it didn't help.

    Too long since I did any programming: D'uh, I'd do better teaching TurboCAD to our cats, they love the cursor changes as it flits across the screens...

    ;-((

    Okay, I'll take another look !!
     
  5. Nik

    Thread Starter Well-Known Member

    May 20, 2006
    55
    3
    Hi, google's just found me several old app-notes (~~ 1995 ) which explain how to squeeze surprising speed out of an otherwise docile 4N25 (LED + opto tranny).

    Techniques include input pulse shaping, cascode amps, open-emitter working, positive feedback...

    I would prefer 6n139, but I can get a Spice model for 4n25 so I'll go with that.

    References:

    Isolation techniques using optical couplers. AN571A Motorola (1995)
    Isolating the control route (topic 2) by Robert Mammano, Unitrode.
    Design of isolated converters using simple switchers, AN-1095, NatSemi (1998)
     
  6. Nik

    Thread Starter Well-Known Member

    May 20, 2006
    55
    3
    I'm learning Anasoft's SuperSpice: their help-desk sent me some useful modelling info, now I'll try to put it to use....
     
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