• Resolved

TPD6S300: / TPD2S300

Part Number: TPD6S300

When using TPD6S300 \ TPD2S300 in my USB Type C design for protection 

1. Is it possible to use Vbus (4.4V - 5.25V) to supply VPWR ? 

2. Should I  be adding ESD Protection Diodes such as TPD1E05U06-Q1 in addition to the TPD6S300 \ TPD2S300 on the CC & USB 2.0\USB 3.0 signals ? Why ? 

Best regards

Shmuel 

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  • In reply to Yongqiang Sun:

    Hi Shmuel,

    Please look here for two previous threads that might answer your question:

    1) https://e2e.ti.com/support/interface/circuit-protection/f/389/t/649627

    2) https://e2e.ti.com/support/interface/circuit-protection/f/389/t/651336 

    In short, look below for my comments/feedback in red: 

    1. Is it possible to use Vbus (4.4V - 5.25V) to supply VPWR ? 

    This is not recommended. At 5.25V, this goes above the abs max of the TPD6s300 (max recommended voltage is 4.5V for both devices). We recommend having a nominal voltage of 3.3V. 

    2. Should I  be adding ESD Protection Diodes such as TPD1E05U06-Q1 in addition to the TPD6S300 \ TPD2S300 on the CC & USB 2.0\USB 3.0 signals ? Why ? 

    There isn't a need to add ESD diodes on the CC and USB 2.0 lines. The TPD6s300 and TPD2s300 have system clamping diodes, as well as other protection circuit blocks. For USB3.0/3.1, please refer to a previous post here: https://e2e.ti.com/support/interface/circuit-protection/f/389/t/651336 

    If this answers your question, PLEASE select  This resolved my issue. Thanks for using TI parts for your design. 

    Best Regards,

    Aramis P. Alvarez

  • In reply to Aramis P. Alvarez:

    Dear Aramis P. Alvarez,

    So for TPD6S300 \ TPD2S300 it seems like I will need a voltage regulator to provide the +3.3V to supply VPWR,

    The only power supply I have is VBUS - can I use this as the input voltage to this 5 to 3.3V voltage regulator ? The reason I ask is if the TPD6S300 \ TPD2S300 is meant to provide protection when the USB cable is connected doesn't the TPD6S300 \ TPD2S300 need to be powered before the USB cable is connected ?

    Best regards

    Shmuel
  • In reply to Shmuel Davis:

    Hi Shmuel,

    You can use the VBUS 5V input to a 3.3V regulator. If the Type-C/PD controller has a generated  3.3V LDO pin, you can use that as well.  In terms of not having power until the cable is plugged in, please refer to the dead battery mode section on both the TPD6s300and TPD2s300 the datasheets.  I hope this helps :-)

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

    Best Regards,

    Aramis P. Alvarez

  • In reply to Aramis P. Alvarez:

    Dear Aramis P. Alvarez,

    Thank you for that.
    Another query:-

    I am placing the TPD6S300 \ TPD2S300 devices in my design for the main purpose that there is poor USB power connection then there might be 20V on the VBUS. Thus the TPD6S300 \ TPD2S300 are there to protect CC, SBU, USB 2.0 lines short to Vbus etc....

    However if there is a concern about 20V on the VBUS lines I assume that is will not be considered a transient voltage ?!

    I have a schematic of the development board for HD3SS3220 and the TPS65981. They have placed a ESD5Z6.0T1G ESD Protection Diode and a NSR20F30NXT5G Schottky Barrier Diode respectively on the VBUS line. If there is a constant 20V on the VBUS how do these protection diodes protect what I am assuming(is this a fair assumption ?) constant 20v ?

    Bets regards

    Shmuel
  • In reply to Shmuel Davis:

    Hi Shmuel,

    The diodes on VBUS on our reference designs are there for high voltage spike transient events (e.g. Hotplugging, ESD, Very Fast FET shutoff, etc.). The breakdown voltage is higher than 20V and hence won't clamp at that voltage. I hope this helps.

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

    Best Regards,

    Aramis P. Alvarez

  • In reply to Aramis P. Alvarez:

    Dear Aramis P. Alvarez,

    So if these diodes are only to protect against " high voltage spike transient events " what about protection for when VBUS is 20V not as a transient ? Which is the reason why I thought it was necessary to place TPD6S300 \ TPD2S300 in the design for the situation if VBUS will not correctly be configured and set to 20V as it states in the data sheets "Since the release of the USB Type-C connector, many products and accessories for USB Type-C have been released which do not meet the USB Type-C specification. One example of this is USB Type-C Power Delivery adaptors that start out with 20 V on the VBUS line...".

    Thus do I not have to be concerned that there might be 20V on my VBUS lines at least initially and how are I meant to protect against this ?

    Best Regards

    Shmuel
  • In reply to Shmuel Davis:

    Hi Shmuel,

    Unfortunately, the TPDxs300 family doesn't protect VBUS. What this family of devices does is it protects the CC and SBU channels from shorting to VBUS. The abs max of the CC and SBU channels are around 5.5-6.5V, whereas the VBUS voltage can go as high as 20V. If any of those pins were to short to VBUS, then certain devices would break downstream.  Also, the datasheet header states that these devices are "Short-to-VBUS" Protection.

    The diodes on VBUS are for transient conditions on VBUS. The highest current paths are going to go through VBUS, hence for the diodes in case of transient events (hotplugging, quick FET shutoff, long wires that become high inductance, etc.).

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

    Best Regards,

    Aramis P. Alvarez

  • In reply to Aramis P. Alvarez:

    Dear Aramis P. Alvarez,

    Thanks for your help ! In the end I got another response from TI and they suggested TPD1S514-1 which I am looking into. Maybe you can suggest to TI that their very good article "TI Circuit Protection for USB Type-C slyy105" should include this info on protection of the devices being powered by VBUS - I don't think I saw any info on this there !?