• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 307 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.

TPA3111D1: Connection between SHUTDOWN and FAULT pin needed to clear FAULT state?

Ryotaro Fukui
Intellectual 2345 points
Part Number: TPA3111D1

Hello team,

i received a question from my customer about the terminal connection of TPA3111D1.

They want to know "if the FAULT terminal need to be connected to the SHUTDOWN terminal"?

(Currently their board, refer to the circuit diagram for the TPA3111D1EVM, could connect the SHUTDOWN and FAULT terminals with a 0 Ω resistor.)

When they set the shutdown terminal from low to high from an external microcontroller, the fault condition could not be cleared if shutdown and fault terminals are not connected

However, when the shutdown and fault terminals are connected, the fault terminal appears to go high after approximately 410ms and clear the fault state. Is this SHUTDOWN and FALUT connection necessary?

I would appreciate if you could give us an advice about it.

Best Regards,

Ryotaro Fukui

  • 0
    TI__Mastermind 24830 points

    Hello Fukui-san,

    The FAULT pin can be cleared by either connecting it to the SHUTDOWN pin or cycling the PVCC power. 

    Hope this helps! 

    Best Regards, 

    Robert Clifton 

  • 0 in reply to Robert Clifton56
    TI__Intellectual 2345 points

    Hello Clifton-san,

    Thank you for your response!

    [About pop noise]

    The customer seems to understood the cause of the popping sound.

    (Their condition of input impedance change from 9k Ω to 60k Ω as a result of the change in the GAIN0 and 1 terminal settings, also seems to match the description provided.)


    [About shutdown & fault pin]

    So in some cases, it is not always necessary to connect the FAULT pin to the SHUTDOWN pin?

    Also, when the SHUTDOWN pin is set to low to high, and the amplifier output is allowed, is there usually no low output on the FAULT pin?

    (This may be due to their misapplication, but their test results shows an output on FAULT pin. Could a DC detect or other condition be happening when the amplifier output is authorized?)

    Best Regards,

    Ryotaro Fukui

  • 0 in reply to Ryotaro Fukui
    TI__Mastermind 24830 points

    Hello Fukui-san,

    Pop

    If I can get a little more clarification. Are you saying the customer is changing the gain settings while the device is on?  

    Shutdown and Fault pin

    If the customer can cycle the PVCC supplies then they would be able to clear the FAULT pin. It's likely that the FAULT pin isn't cleared just from toggling the SHUTDOWN PIN. 

    I'm not fully clear on how they are misusing so I'm not sure I can answer your last question. Can you provide more details? 

    Thank you,

    Robert Clifton 

  • 0 in reply to Robert Clifton56
    TI__Intellectual 2345 points

    Hello Clifton-san,

    Pop

    Sorry for the confusion, I was asking about pop sound in another thread. I just mistakenly replied to this thread.

    It has been already solved, but just in case I will write the details below.

    As a result of testing on the prototype board, the speaker volume was sufficient and the white noise was high, so they changed the setting terminals GAIN0 and 1 were changed from high to low, respectively. Not when the power is turned on. This change seems to caused the mentioned pop sound, but after they changed the capacitor it was solved.

    Shutdown and Fault pin

    So if they can cycle the PVCC power supply, it is ok to keep those two pins disconnected. They seem to be concerned that disconnecting those, might occur issue for some another reason.

    I would ask them if they could provide us with more detailed information about their circuit. So normally, is it ok to understand that if the shutdown pin is set from low to high and the amplifier output is allowed, low is not output on the fault pin?

    Best Regards,

    Ryotaro Fukui

  • 0 in reply to Ryotaro Fukui
    TI__Mastermind 24830 points

    Hi Ryotaro,

    Once the FAULT is cleared, then the amplifier's outputs are able to switch. If the customer only toggles the shutdown pin and not cycle the PVCC supplies then the Fault condition will not be cleared, if FAULT and Shutdown pins aren't tied together.

    But if the Fault pin is tied to shutdown then toggling the shutdown pin might be all that's needed to clear the fault depending on the fault condition. 

    Best Regards,

    Robert Clifton