Electrical – Bulletproof ESD Powersupply Inputs

amplifierdiodesesdprotectiontvs

I have a power amp that is essentially functions like a benchtop supply, and you can connect banana plugs into it. I would like to protect it against ESD, but also protect the amplifier. People in our manufacturing floor are stupid and sometimes connect things like batteries to the supply up backwards, I really can't prevent that, and if they do they will blow the diode right out. Is there a good way to protect the diode also? These are the ways I could protect it that I don't necessarily like:

  1. I could fuse it but there would be no way to know if the fuse was blown and then you still have no diode and no protection and nobody on our floor would replace it.
  2. Resistor in series, I don't like this idea because it makes the diode less able to sink ESD and protect the input. 8kv (human body model) across a 1ohm resistor is 8000V
  3. Placing a resistor anywhere from the amp to the terminal will be bad, too much current.

schematic

simulate this circuit – Schematic created using CircuitLab

Best Answer

If you use bidirectional TVS diodes instead of unidirectional TVS diodes and spec them above the possible battery that could be connected this would protect your output.

schematic

simulate this circuit – Schematic created using CircuitLab

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