• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 2 answers
  • Subscribers 62 subscribers
  • Views 407 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.

TPS1H200A-Q1: Problems signal fault

VBM-Electronic
Prodigy 185 points
Part Number: TPS1H200A-Q1


Hi,

I used thi to monitor the current of 5Vdc and 24Vdc in stand-alone configuration with fault signal monitoring.

The 5Vdc circuit (see attached photo) works well and the signal fault goes low in the case of high current, but the 24Vdc monitoring circuit (see attached photo), the fault signal always remains low, always active, I don't understand why, you can help me?

Thank you

  • 0
    TI__Genius 16390 points

    Hi,

    Would you try to tie the Delay pin at 24V circuit to 3.3V and see if you still see a constant low fault? The abs max for the DELAY pin is 7V. Also at this point I'm not sure if the device is damaged by having too large voltage at DELAY pin. It might be worth a while to replace a new IC and test the 24V case again.

    Regards,

    Yichi

  • 0
    Prodigy 185 points

    Hi Yichi, thanks for the reply. Maximum PIN delay voltage was my first idea. I replaced the chip with a new one and I brought the pin delay to 5Vdc, but it still didn't work. Also from the datascheet you will find this example:

  • 0 in reply to Yichi Zhang.
    Prodigy 185 points

    Hi Yichi, thanks for the reply. Maximum PIN delay voltage was my first idea. I replaced the chip with a new one and I brought the pin delay to 5Vdc, but it still didn't work. Also from the datascheet you will find this example:

    in this diagram the delay pin is connected to Vs through an R100K and Vs can reach a maximum of 40V. If I power the circuit at 24Vcc and measure the voltage on the delay pin is less than 7Vcc despite the RUp at 24Vcc, I believe that the pin internally keeps itself below the maximum 7V protected by the R100K.

    The chip works, limits the output current and Auto-Retry works, the only thing wrong is that at 24V the PIN fault remains low.

    Thank you

  • 0 in reply to VBM-Electronic
    TI__Genius 16390 points

    Thanks for the additional info. Is the fault low even when the input is disabled? 

    Could you probe input voltage, output voltage, current and FAULT for both IN high and IN low cases?

    That might give us some clues.

    Regards,

    Yichi

  • 0 in reply to Yichi Zhang.
    Prodigy 185 points

    Hi Yichi,

    I discovered my problem, the fault signal is activated for the open load, in my application there is not always a load. I would only need to report any short circuits and not the open load, is there a similar High-side switch, but without open load control?

    Thank you

  • 0 in reply to VBM-Electronic
    TI__Genius 16390 points

    Hi,

    For this device, to differentiate an open load and a short-circuit, you can see the output voltage. If the output voltage is high (around VS), then it's open-load condition; if the output is low, then it would be short-circuit. Does that work in you applications?

    Regards,

    Yichi

  • +1 in reply to Yichi Zhang.
    Prodigy 185 points

    Hello,
    I thought the same thing, instead of using the pin fault I make a voltage divider on the output, checking the voltage I check for a short circuit. Thank you