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TPD6S300: ESD Protection

Shmuel Davis
Expert 2920 points
Part Number: TPD6S300
Other Parts Discussed in Thread: TPD2S300, TPD1E05U06-Q1

We are using a FTDI FT601 controller to communicate with our USB TYPE C connector. It has the following ESD protection (taken from Data sheets)

In our design we have connected the USB 2.0 DP/DN signals to a TPD6S300 (which we also use to protect the CC lines).

1. Is the above protection provided by the FT601 chip enough that we can replace the TPD6S300 with smaller simpler TPD2S300 that will only protect the CC lines ?

2. If the above protection is not enough - is there any issues of double protection and the effect on the USB signals ?

Best regards

Shmuel 

  • 0
    TI__Genius 10370 points

    Hi Shmuel,

    If you need your SBU lines protected as well, then the TPD6s300 is the correct part. The TPD2s300 only protects CC lines to VBUS. With respect to enough ESD protection, I cannot answer that for you.  The designer decides what's enough protection for their system in terms of voltage and what type of ESD class they need in their system.

    One last note, you could possibly add a HUB that muxes the D+/D- lines from the type-c connector to either the FTDI chip or the protection device.

    I hope this helps and If this answers your question, PLEASE select  This resolved my issue 

  • 0 in reply to Aramis P. Alvarez
    Expert 2920 points
    Dear Aramis P. Alvarez,

    Thank you for your quick reply.

    We are not using the SBU lines thus the TPD2S300 should be sufficient ?

    My question really was does the FTDI ESD have ATLEAST the same level of protection as the TPD6S2000 and if so then we can go down to the TPD2S300 ?

    Also is there any issues of "double protection" that would require me ensure that these lines are not connected to the TPD6S300 ?

    Best regards

    Shmuel
  • 0 in reply to Shmuel Davis
    TI__Genius 10370 points

    Hi Shmuel,

    The above ESD models for the FTDI chip are JEDEC Specs.

    Our TPD6s300 is rated for JEDEC and IEC specs. Most systems need to pass IEC specs, but again I cannot answer that question for you. If you need to pass IEC specs for ESD then I would recommend using the TPD6s300. The double protection shouldn't affect the D+/D- lines as long as you have some kind of mux to pass the data to either the FTDI or to any other device downstream.

    If this answers your question, PLEASE select  This resolved my issue 

  • 0 in reply to Aramis P. Alvarez
    Expert 2920 points
    Dear Aramis P. Alvarez,

    Thank you for that clarification.

    Our USB DP\DN signals are currently connected to the TPD6S300 and also the the FT601 ONLY. Thus why would I need the MUX your are referring to and what has this got to do with the "doubling" of the ESD protection ?

    I was told that the USB TYPE C Spec states that the 2 sets of DP1\DP2 and DN1\DN2 signals can be shorted together without the requirement for any MUX as long as the stub is less than 3.5 mm long. ???

    Best regards

    Shmuel
  • 0 in reply to Shmuel Davis
    TI__Genius 10370 points

    Hi Shmuel,

    I don't believe the doubling of protection is the problem, I believe the issue you might have is with a long stub connected to both the FTDI and the protection device. Having a Mux/hub of some sort will prevent the stub from happening. That way, you can first talk to the FTDI to set flash your memory, and then mux the data lines back to the system.

    For stub length, please refer to the USB2.0 specs on usb.org

    I hope this helps and If this answers your question, PLEASE select  This resolved my issue 

  • 0 in reply to Aramis P. Alvarez
    Expert 2920 points
    Dear Aramis P. Alvarez,

    If the protection device is placed much closer to the USB Type C connector c.f. the distance between the FTDI chip and the USB Type C connector then this should solve the concern no ?

    Please could you explain this a little more : "you can first talk to the FTDI to set flash your memory, and then mux the data lines back to the system" - the only IC that is connected to the USB is the FTDI chip and the protection device ???

    In the end I think we have decided to go with the TPD2S300 for the CC lines, and use the TPD1E05U06-Q1 diodes for ESD protection since this will give a simpler (we are using both of these devices already in the system) design and more compact !

    I am right that the TPD1E05U06-Q1 can be also used for the USBN 2.0 lines (we are using them for the High speed USB 3.0 lines currently) ?

    Best regards

    Shmuel
  • 0 in reply to Shmuel Davis
    TI__Genius 10370 points

    Hi Shmuel,

    The D+/D- lines do not go through the  TPD6s300, instead one will just tap the D+/D- channels on the pins on our device for clamping.  When I meant about having a stub is that if one taps the D+/D- channels to both the FTDI and TPD6s300, one must be careful to not have long stubs on both of these lines. Just an FYI.

    With respect to the TPD1E05U06-Q1, please post a new question with this part number so that your question is routed to the appropriate engineer who supports this part :-)

    If this answers your question, PLEASE select  This resolved my issue