• State Resolved
  • Locked Locked
  • Replies 13 replies
  • Answers 6 answers
  • Subscribers 32 subscribers
  • Views 2854 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPD13S523: Short Mode of TPD13S523

yoshiki hasebe
Mastermind 6385 points
Part Number: TPD13S523
Other Parts Discussed in Thread: TPD5S116

Dear Sirs,

My customer asked us about behavior in short mode of TPD13S523 .

I found the following description about the short mode of 5 V OUT and GND.

The short-circuit protection at 5V_OUT ensures that the device is not damaged in case there is an accidental short to GND.

So, what happens to the short mode of 5V_OUT and Power Supply(VCC Voltage)?

Best Regards,

Y.Hasebe

  • 0
    TI__Intellectual 1445 points

    Hi,

    For the TPD13S523, the protection is only rated for the instance where the GND is shorted to the 5V_Out. In HDMI interfaces, pins 17 (GND) and pin 18 (VCC) are close together and have the possibility of shorting in the case the pins are bent when plugging in.

    The 5V_Out is connected to the Supply (VCC) through the load switch as shown below.

    The below snippet also shows how the two interact within the device.

    I hope this helps!

    Very Respectfully,

    Brian Dempsey

  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank  you for your reply.

    I understood the connection condition with the comment received.

    However, my customer wants to check the effect of the device when 5 V - Power Supply and 5 V - OUT are shorted.

    If your 5 V - Power Supply and 5 V - OUT are shorted from your comment, I think that the device will be protected with 55 mA LOADSW.

    is it right?

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    TI__Intellectual 1445 points
    Hasebe-san,

    I believe you are correct. The load switch will protect the device in the event the power supply and 5V out are connected together. Hope this helps!

    Very Respectfully,
    Brian Dempsey
  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank you for your reply.

    I was misunderstanding the information from the customer.

    Please let me know the behavior of IC when 5 V-OUT and 12 V (Automotive) of battery short-circuited.

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    TI__Intellectual 1445 points

    Hi Hasebe-san,

    After running a quick test in the lab, I do not see any effect on the V_supply. This test was done by shorting a 12 VDC source with the 5V_Out pin of the device. Below, the blue waveform is the voltage level on the shorting board, the pink is the voltage level of the 5V_Out pin, and the green waveform is the 5V input voltage of the system.

    This does not indicate any issues when the 12 VDC is shorted to the 5V_Out, but due to the lack of information in the datasheet pertaining to this event occurring, it can't be guaranteed as an intended function. I hope this helps!

    Very Respectfully,

    Brian Dempsey

  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank you for your kindly reply.

    I have one more question.

    Short time seems to be 4.5ms from your test data.

    What happens if the short mode continues?

    Is there any concern that the IC will be broken?

    Is it no problem keeping shorting?

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    Mastermind 6385 points
    Hello Brian-san,

    Sorry, I forgot following question.
    Could you please tell me the test circuit of the waveform that you gave me last time?

    I'm sorry not send collectively question.

    Best Regards,
    Y.Hasebe
  • 0 in reply to yoshiki hasebe
    TI__Intellectual 1445 points

    Hi Hasebe-san,

    After a second round of testing, the following waveforms are not showing any issues with respect to a prolonged short condition. The first test is done with no voltage at the source, the green waveform, and a 12V short, the blue.

    For the second test, the source is powered up with 5V and the response of the system is acquired after applying a constant short. There were no issues seen here either.

    As far as the testing setup, we are using a multi-channel DC power supply,  a short to VBUS board with VBUS set at 12V and an HDMI product EVM (TPD5S116) with the same power protection as the target device.This EVM boardt can be found on TI.com. I hope this helps!

    Very Respectfully,

    Brian Dempsey

  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank you for your kindly reply.

    I have additional question.

    1.I tried to make your setup as follows.

    　Is it correct?

    2.As your test data 2,

       1) In the first test, a voltage drop (about 4 V) occurs in the short circuit, and then it seems to be maintained at 8 V.

       2) In the second test, a voltage drop (about 2 V) occurs in the short circuit, and then it seems to be maintained at 10 V.

    What are the causes of the above?

    Also, is there no problem if this situation lasts for a long time?
    It seems from the data sheet that ZenerDiode between 5 V - OUT and GND is on.

    Best Regards,

    Y.Hasebe

           

      

  • 0 in reply to yoshiki hasebe
    TI__Intellectual 1445 points
    Hi Hasebe-san,

    These voltage levels are due to the clamping voltage of the test device. The level increases with current and because in the 2nd test we have two sources on, we are seeing a higher current level. Thus, when the circuit clamps, there is a slight change in the voltage clamp level.

    As far as the test setup, we are powering the 5V_sys off of the VCAA voltage @ 5V and the 5V_CON from the V_CON. The 12V is introduced on the middle pin on the CON side. you are correct. Before applying the 12V, ensure that you have 5V on both the SYS and CON.

    Hope this helps!

    -Brian
  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank you for your quick reply.

    My customer's question is whether the destruction (smoking, ignition, etc.) does not occur if 5 V-OUT and 12 V are short-circuited and keeping that state for a long time.

    Is it due to ZenerDiode of the internal circuit due to the Clamp voltage?
    Or is there any other factor to clamp?

    Best Regards,

    Y.Hasebe

  • 0 in reply to yoshiki hasebe
    TI__Intellectual 1445 points
    Hi Hasebe-san,

    We haven't done long term 12V shorting to test the destruction resistance of the device, but I have not seen any effects when testing in lab for 10-15 minutes. Also, the Zener diode is responsible for the clamping of the 5V_OUT voltage.

    My recommendation for the 12VDC short to 5V_out testing would be to have the customer test this in house. As I mentioned we cannot guarantee anything not specified in the datasheet, so testing at their facilities would be the most appropriate action.

    Very Respectfully,
    Brian Dempsey
  • 0 in reply to Brian Dempsey
    Mastermind 6385 points

    Hello Brian-san,

    Thank you for your quick and kindly reply.

    I understand your comments.

    I will reply to my customer on your comment.

    Best Regards,

    Y.Hasebe