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Op Amp burning

  1. May 3, 2012 #1
    Hello. This post is mainly dedicated to YUNGMAN. I used your trick with Transorb in a class B amplifier driving coils. Unfortunataly these Transorbs introduced more than 1 nF capacitance and so the amplifier produce a large high frequency oscillation. Without Transorb, one more time LM324 is burned. Do you have an other idea ? Thanks by advance.
  2. jcsd
  3. Jul 6, 2012 #2


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    Staff: Mentor

    To drive a capacitive load, the usual trick is to drive it through a series resistor. How big of a series resistor can you use in your application? Or did you solve this problem another way?
  4. Jul 6, 2012 #3
    My god, I post dedicated for me!!!!:bugeye::rofl:

    Anyway, they have smaller and lower capacitance transorbs. Go to Digikey:


    Type TVS array,

    This is one of the example:


    There are plenty bus TVS array that you can look into. I don't remember what I said in the last post anymore for very obvious reason........OLD AGE!!!:cry: Like Berkeman advice, if you worry about those small TVS can't handle the power, put a small series resistance from the board input to the op-amp input. Then put the TVS right at the input. You'll be surprised even a few hundred ohms can really protect the op-amp.
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