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TPS25730A: Questions regarding TPS25730A usage

Takashi Imai
Intellectual 440 points

Part Number: TPS25730A
Other Parts Discussed in Thread: TVS2200, TPD4S201

Hello,

I have received the following 4 inquiries from a customer. I would appreciate your support in responding to the customer.  The customer plans to use the TPS25730A as a sink controller with a 20 V / 4 A output. 

1. Recommendation for VBUS-line Schottky diode

Section 8.4.2 of the TPS25730A datasheet describes the use of a Schottky diode for current surge protection. On the other hand, the TPS25730A EVM schematic shows a TVS2200DRVR connected to VBUS. 
Could you please clarify which solution is recommended for a production design?
If a Schottky diode is recommended, could you please provide the TI recommended part number?
If there is no specific TI recommendation, could you please advise the key electrical characteristics and selection criteria that should be considered when choosing a suitable third-party Schottky diode?

2.Please advise on the proper handling of the following pins when they are not used on the PS25730AD?

  • Pin 6: CAP_MIS
  • Pin 10: DBG_ACC
  • Pin 13: PLUG_FLIP
  • Pins 15, 30: DRAIN
  • Pin 19: _SINK_EN
  • Pin 37: PLUG_EVENT

3. Handling of VIN_3V3 pin

The customer will not use the VIN_3V3 supply and plans to power the TPS25730A from VBUS only. 
Table 5-1 of the datasheet states that VIN_3V3 should be tied to GND when the device is VBUS-powered only. However, Figure 9-5 shows VIN_3V3 connected to GND through a 10-µF capacitor. 
Could you please clarify which connection method is recommended for this use case?

4. Does the TPS25730A support detection of a VBUS voltage mismatch?

If a USB PD contract is established at 20 V, but the actual VBUS voltage later deviates from the negotiated value due to a source-side fault (for example, 15 V instead of 20 V), is there any mechanism to detect this condition and disable the VBUS power path automatically?
I could not find any feature corresponding to this function in the TPS25730A datasheet. Could you please confirm whether this capability is supported?
If not, could you please recommend an implementation method or external circuitry to achieve this protection function?

Thanks & Regards,
T.Imai

  • 0
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    1. Recommendation for VBUS-line Schottky diode

    Both the TVS and the Schottkey would be recommended.  TVS2200 and something like the B340LA/B.

    Takashi Imai said:
    2.Please advise on the proper handling of the following pins when they are not used on the PS25730AD?
    • Pin 6: CAP_MIS , if unused leave floating
    • Pin 10: DBG_ACC, if unused leave floating
    • Pin 13: PLUG_FLIP, if unused leave floating
    • Pins 15, 30: DRAIN; please refer to the datasheet.  This should be connected to the drain pad and then also brought to the opposite layer for thermal purposes: https://www.ti.com/lit/ds/symlink/tps25730a.pdf#page=46
    • Pin 19: _SINK_EN, if unused leave floating
    • Pin 37: PLUG_EVENT, if unused leave floating
    Takashi Imai said:
    3. Handling of VIN_3V3 pin

    For a VBUS power only the VIN_3V3 should be connected to ground.  The example in figure 9-5 was taken from an example which supports powering from VIN_3V3.  Please follow the description in Table 5-1 and connect to ground.

    Takashi Imai said:
    4. Does the TPS25730A support detection of a VBUS voltage mismatch?

    I will need some more time to confirm if this feature is available. 

    Regards,

    Chris

  • 0 in reply to Chris Sterzik
    Intellectual 440 points

    Hi Chris-san,

    Thank you for your prompt reply. 
    Chris Sterzik said:
    Both the TVS and the Schottkey would be recommended.  TVS2200 and something like the B340LA/B.
    Is it correct that we can use either one of them, rather than both?

    Chris Sterzik said:
    I will need some more time to confirm if this feature is available.

    Understood. Thank you for the confirmation. Please share an update here once you have determined whether the TPS25730A supports this function.

    Thanks & Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    Is it correct that we can use either one of them, rather than both?

    Since the customer is intending to support 4A of current, I would recommend considering what will the impact of a disconnect from the far end  would be and if the Schottkey diode would be needed.

    If the customer is only willing to place one protection item, then i would recommend placing the TVS2200.

    Regards,

    Chris

  • +1 in reply to Chris Sterzik
    Intellectual 440 points

    Hello Chris-san,

    Thank you for your reply.

    For now, I will recommend that the customer use the TVS2200 on both the VBUS and CC1/CC2 lines.

    They will begin their evaluation using the EVM. Although the impact of a far-end disconnect is still unclear, I do not expect it to be an issue during the evaluation.

    If any issues arise during the evaluation, or after the customer implements the design on their own board, I will open a new thread and follow up accordingly.

    Thanks & Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    Intellectual 440 points

    Hi Chris-san,

    Regarding the question 4 below, I forgot that I have not received an answer yet, but could you please answer this?

    >> 4. Does the TPS25730A support detection of a VBUS voltage mismatch?

    > I will need some more time to confirm if this feature is available. 
    Thakks & Regards,
    T.Imai
  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    I will recommend that the customer use the TVS2200 on both the VBUS and CC1/CC2 lines.

    If you need to protect both the VBUS and the CC lines then I would recommend also considering the TPD4S201, but I am not sure if the cost is less.

    Takashi Imai said:
    Regarding the question 4 below, I forgot that I have not received an answer yet, but could you please answer this?

    I am working on the details.  I can confirm that the TPS25730A does monitor VBUS for under voltage events (under voltage protection).  I can give you an update on my status 09/01/2026.

    Regards,

    Chris

  • 0 in reply to Chris Sterzik
    Intellectual 440 points

    Hi Chris-san,

    Chris Sterzik said:
    If you need to protect both the VBUS and the CC lines then I would recommend also considering the TPD4S201, but I am not sure if the cost is less.

    Thank you for recommending the TPD4S201.
    When comparing prices, the TPD4S201 is approximately three times more expensive than the TVS2200. In addition, the TPS25730A datasheet recommends the TVS2200.
    Although I will introduce the TPD4S201 to the customer as an alternative option, if the customer asks whether the TVS2200 is still acceptable, my understanding is that the TVS2200 can also be used without issue. Could you please confirm whether this understanding is correct?

    Chris Sterzik said:
    I am working on the details.  I can confirm that the TPS25730A does monitor VBUS for under voltage events (under voltage protection).  I can give you an update on my status 09/01/2026.

    Thank you. I look forward to hearing your update.

    Best Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    Although I will introduce the TPD4S201 to the customer as an alternative option, if the customer asks whether the TVS2200 is still acceptable, my understanding is that the TVS2200 can also be used without issue. Could you please confirm whether this understanding is correct?

    Yes.  That is correct.

    I am still working on the update regarding the UVP feature.

    Regards,

    Chris

  • +1 in reply to Chris Sterzik
    Intellectual 440 points

    Hi Chris-san,

    Thanks a lot for your support.

    Best Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    Intellectual 440 points

    Hi Chris-san,

    Chris Sterzik said:
    Takashi Imai said:
    Regarding the question 4 below, I forgot that I have not received an answer yet, but could you please answer this?

    I am working on the details.  I can confirm that the TPS25730A does monitor VBUS for under voltage events (under voltage protection).  I can give you an update on my status 09/01/2026.

    I realized that I have not yet received your response to Question No. 4.I apologize for the reminder, but would appreciate it if you could provide an answer at your earliest convenience.
    Once this item is addressed, all of the customer's current questions will have been answered.

    Thanks & Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    Intellectual 440 points

    Hi Chris-san,

    Sorry for the consecutive questions.

    The customer has come back with an additional question regarding the protection devices for the TPS25730A. The TPS25730A datasheet recommends the TVS2200 for the VBUS, VBUS_IN, CC1, and CC2 pins. However, the TPS25730A EVM uses the TPD4S201 on the CC1 and CC2 lines.

    Could you please clarify the rationale for using the TPD4S201 on the EVM?

    Thanks & Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    Could you please clarify the rationale for using the TPD4S201 on the EVM?

    The TPD4S201 provides a fault indicator which can be used to drive the /FAULT_IN pin of the TPS25730A.

    Takashi Imai said:

    4. Does the TPS25730A support detection of a VBUS voltage mismatch?

    If a USB PD contract is established at 20 V, but the actual VBUS voltage later deviates from the negotiated value due to a source-side fault (for example, 15 V instead of 20 V), is there any mechanism to detect this condition and disable the VBUS power path automatically?
    I could not find any feature corresponding to this function in the TPS25730A datasheet. Could you please confirm whether this capability is supported?
    If not, could you please recommend an implementation method or external circuitry to achieve this protection function?

    The TPS25730A does provide a UVP (under voltage protection feature).  When the voltage falls before the UVP threshold for a USBC-PD contract voltage the power path will turn off and the /SINK_EN pin will be released.  The PD controller will perform a type-C error recovery.  For an non-PD 5V contract, the power path will turn off and the /SINK_EN pin will be released.   No error recovery is performed and the type-c connection remains. 

    Contract Voltage  UVP Threshold 
    5 2.5V
    9 6.5V
    15 11.5V
    20 16.5V

     Regards,

    Chris

  • 0 in reply to Chris Sterzik
    Intellectual 440 points

    Hello Chris-san,

    Thank you for your support.

    Chris Sterzik said:
    The TPD4S201 provides a fault indicator which can be used to drive the /FAULT_IN pin of the TPS25730A.

    So, my understanding is that the TPD4S201 was included on the EVM to demonstrate an optional fault-reporting feature, where abnormal conditions such as overvoltage can be communicated to the TPS25730A through the /FLT output. Is this correct?

    Regarding VBUS voltage mismatch function, I'm glad to hear that the TPS25730A supports VBUS voltage mismatch detection. 

    The customer would like to know how they can confirm that the TPS25730A supports VBUS voltage mismatch detection and the functionality described below. Could you please advise whether this capability is described in the datasheet, TRM, or any other relevant documentation?

    Chris Sterzik said:
    The TPS25730A does provide a UVP (under voltage protection feature).  When the voltage falls before the UVP threshold for a USBC-PD contract voltage the power path will turn off and the /SINK_EN pin will be released.

    Thanks & Regards,
    T.Imai

  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    So, my understanding is that the TPD4S201 was included on the EVM to demonstrate an optional fault-reporting feature, where abnormal conditions such as overvoltage can be communicated to the TPS25730A through the /FLT output. Is this correct?

    Yes.

    Takashi Imai said:
    The customer would like to know how they can confirm that the TPS25730A supports VBUS voltage mismatch detection and the functionality described below. Could you please advise whether this capability is described in the datasheet, TRM, or any other relevant documentation?

    No.  This capability is not described in the any relevant documentation.  My recommendation would be to find an alternative solution.  If the customer were to attempt to use this capability and an issue were to arise then TI would not accept responsibility because there is no mention of this feature in the datasheet or TRM.

    Regards,

    Chris

  • 0 in reply to Chris Sterzik
    Intellectual 440 points

    Hello Chris-san,

    Thank you for your support.

    Regarding VBUS voltage mismatch detection, I'd like to confirm my understanding. Is it correct that the TPS25730A does not support this functionality?
    Thanks ＆Regards,
    T.Imai
  • 0 in reply to Takashi Imai
    TI__Guru 74341 points

    Hello,

    Takashi Imai said:
    Regarding VBUS voltage mismatch detection, I'd like to confirm my understanding. Is it correct that the TPS25730A does not support this functionality?

    Yes.  This function is not is not available/documented at this.    


    Regards,

    Chris

  • +1 in reply to Chris Sterzik
    Intellectual 440 points

    Hello Chris-san,

    Thank you for your support. I will close this thread for now. If I have any further questions, I will open a new thread.

    Thanks & Reagrds,
    T.Imai