• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 33 subscribers
  • Views 137 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS2595: request for a schematic check (TPS259530).

user6224889
Prodigy 70 points

Part Number: TPS2595

This question is related to a previous thread I posted.
https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/1607255/tps2595-request-for-a-schematic-check-tps259530/6195569

 - Background -
The target of this discussion is “Board 1” in the following configuration:
Configuration: USB Type‑C connector <-> Board 1 (equipped with TPS259530DSGR) <-> Board 2 (DC‑DC / battery circuitry)
Role: Board 1 is designed to cut off power to Board 2 when an abnormal condition (such as a failure) occurs on Board 2.

 - Question -
When I powered Board 1 while a faulty Board 2 was connected, the TPS259530DSGR and the PCB on Board 1 reached temperatures of around 90°C.
Because Board 1 is very compact, I am concerned about the risk of burns if a user accidentally touches it.
As a countermeasure, I replaced the pull‑down resistor connected to the EN/UVLO pin of the TPS259530DSGR with an NTC thermistor.
As a result, I was able to reduce (limit) the temperature of the board and components to around 60°C.

From my perspective, this modification does not introduce any major drawbacks.
However, if there are any potential disadvantages or design concerns associated with replacing the resistor with an NTC thermistor,
I would appreciate your insights.

image.png

 

  • 0
    TI__Genius 9780 points

    Hi ,

    The disadvantage could be   that , so when the temperature increases, the resistance decreases of pull down resistor decreases ,thereby the voltage of EN pin might increase than the maximum voltage it can hold,thereby efuse getting damaged So can you help me in telling what will be the resistance range of pull down resistor 

    Best Regards,

    Sailendra

  • 0
    Prodigy 70 points

    Dear Sailendra,

    Thank you for your reply and for sharing your thoughts.
    The NTC thermistor changes its resistance as follows, for example:
    “0°C = 4.29 MΩ / 25°C = 1 MΩ / 60°C = 187 kΩ”.
    Based on the calculation, I believe the EN-pin voltage will be as follows:
    “0°C = 4.25 V / 25°C = 2.86 V / 60°C = 1.00 V”.

    Therefore, I think the EN-pin voltage will not exceed its rating.
    Could you please confirm this?

    (I wanted to upload the graph showing the IC temperature and the measured EN-pin voltage, but an error occurred, so I am sharing only the numerical values.)

  • 0 in reply to user6224889
    TI__Genius 9780 points

    Hi ,

    The data is helpful,

    You can install the thermistor

    Best Regards,

    Sailendra