SSM2019 fails with high input current

We are using SSM2019 for balanced MIC pre-amp. It is powered by +/- 15v source.

Occassionaly a device fails in operation with no apparent reason. When testing failed device with multi-meter it looks like the input stage broke but I can't be sure on that.

The design include schottky diodes (BAR43CFILM) for clamping the input signals. In addition the microphone input connector has ESD protection diodes (TPD2E007).

Any ideas?

Thanks,

David

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  • Hi David,

    It looks like you are doing some rigorous ESD and EMC protection. I am curious about the connection between CH_GND and GND_ANALOG_AUDIO. Do you have other isolated ground nets in the design? I generally recommend that designs have only one single ground with one single solid ground plane.

    With regards to the units that have failed, did they fail in service or after assembly? Do they all appear to fail in the same way? Have you removed the IC off the board to confirm that the broken input that you describe is in the SSM2019 and not in one of the passives on the board?

    Regards,

    Coleman

Reply
  • Hi David,

    It looks like you are doing some rigorous ESD and EMC protection. I am curious about the connection between CH_GND and GND_ANALOG_AUDIO. Do you have other isolated ground nets in the design? I generally recommend that designs have only one single ground with one single solid ground plane.

    With regards to the units that have failed, did they fail in service or after assembly? Do they all appear to fail in the same way? Have you removed the IC off the board to confirm that the broken input that you describe is in the SSM2019 and not in one of the passives on the board?

    Regards,

    Coleman

Children
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