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TPD1E0B04: TPD1E0B04 ESD Protection for USB in Uncontrolled ESD Envrionment

Sasha
Prodigy 30 points
Part Number: TPD1E0B04
Other Parts Discussed in Thread: TPD1E01B04

Hello All,

I want to hardened USB ports in an uncontrolled ESD environment e.g., office environment. Additionally, I don't want the user to have to wear a ESD wrist strap when plugging in the USB cable, i.e. I don't want to label the port with an RS-471 sticker! Will this IEC 61000-4-2 8 kV provide sufficient protection?

In the literature I've been reading, IEC 61000-4-2 only tests in the powered state when the system is operational and looks for soft faults. However, i'm also concerned with damage when the equipment is in an unpowered state and any hard faults that may be associated with that. It seems an ESD path in unpowered vs. powered state can vary widely. Will the TPD1E0B04 provide sufficient ESD protection when the equipment is in both unpowered and powered states? 

  • 0
    TI__Genius 13760 points

    Hi Sasha,

    Welcome to E2E!

    The only way to find out if the device has sufficient protection would be know the magnitude of the ESD events that the system might encounter in your environment. Different standards have certain levels of protection a system must meet. Whether the device can protect or not would completely depend on the fault scenario expected.

    In both the powered and unpowered states the TPD1E01B04, and other ESD devices in our portfolio, will offer the same level ESD protection, but the total ESD protection in the system will be different in both states. The IC's that are being protected also have some ESD capabilities which adds to the total ESD protection when the system is powered. In an unpowered system the ESD capabilities of some IC's will be disabled leaving the ESD device as the only protection.

    Best regards,

    Andy Robles

  • 0 in reply to Andy Robles
    Prodigy 30 points

    Andy,

    That was a very informative response, thank you for the input! Could that be part of the reasoning why IEC-61000-4-2 now exclusively conducts ESD testing in a powered state? In previous versions (IEC 801.2)  system level testing was done in an unpowered and powered state. 

  • 0 in reply to Sasha
    TI__Genius 13760 points

    Hi Sasha,

    I'm not entirely sure I'm following. The IEC 61000-4-2 tests for the ESD capabilities of the device. Our devices do not need to be powered, so individually they provide the same protection in a system that is powered and un-powered.

    Best regards,

    Andy Robles

  • 0 in reply to Andy Robles
    Prodigy 30 points

    Yes, I agree with you.

    I was looking at older versions of the IEC standard. In that standard (IEC 802.1), there are procedures which tests the external terminals in a powered and unpowered state.

    IEEE C63.16 which is a tailored procedure of IEC-61000-4-2 also allows testing in an unpowered state, as well as injection directly into the connector pins. MIL-STD-1686B Appendix C also included a "system level" test which tested the external terminals of the equipment in an unpowered state. 

    My original question arose from this variance in system level test standards and why some (usually older standards) also tested in the powered and unpowered state. 

  • 0 in reply to Sasha
    TI__Genius 13760 points

    Hi Sasha,

    I see what you mean now. If you would like to learn more about the test for our ESD devices I encourage you to take a look into this application report: IEC 61000-4-x Tests for TI’s Protection Devices


    Best regards,

    Andy Robles