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TLV9002: Component burn out issue!!! And need support

Part Number: TLV9002

Hi team,

My customer use this device in their system and recently they are highlighting 11pcs devices are damage in factory.

And all these failure sample are damage pin8 and pin9.

I attach their portion circuit and please help to double check is there any strange?

And could you advise output pin ABS max voltage rating, in datasheet, we didn't see this parameter?

Thanks

  • Hi Paul,

    please show a complete schematic so that we don't need to guess. And please explain what role U26 plays.

    Kai

  • Hi Paul,

    Kai is correct, some clarification would be very helpful.

    Is U910A in a buffer configuration, where pin 9 is directly tied to pin 8? 

    We don't usually specify what the OUT pin's absolute max voltage rating is since it's an output and is derived from the Electrical Characteristics table section talking about it's voltage output swing from supply rails shown here:

    Best Regards,

    Robert Clifton 

  • U26 is only switch to set audio path. 

    Red arrow is the audio output path from SOC to output connector (connected with C292.2, net name is PositiveBus).

    Yellow arrow is the microphone path from the same connector (C292.2) to SOC.

    The connector pin (C292.2) is used for output & input function. The output and input pin is the same one pin.

     As a result, when recording, the signal passes throung C292 to U909B, and also enters U910A.9 & U910A.8. 

    For normal TLV9002, our PE got the impedance was about 30M ohm from U910.8 to GND. But our PE found the impedance of bad U910A.8 was low about 12ohm. 

    So about the bi-direction use case,

    1. could TI suggest the maximum voltage TLV9002 pin 8 & pin 9?

    2. does TI have any other suggestion?

  • The attached figure is the waveform when DUT is powered on. 

    There is a pulse of U910.8, about 2.317V. 

    So we want to know the voltage spec of U910.8 (TLV9002 pin 8).

  • Hi Peter,

    I would add current limiting resistors to the +inputs of U909A, U910A and U910B. U26 would also profit from such a current limiting resistor. Then I would add a biasing resistor from pin4 of U26 to signal ground. And I would increase R304, to reduce the current spike into the output of U910A.

    Kai

  • Robert,

    According to customer's feedback, due to there is voltage spike appeared in OUT pin when power on.

    So that's why they would like to know OUT pin ABS max voltage rating?

    Could you advise?

    BTW, My customer also asked some question in this Thread , so please help to response.

    Thanks

  • Hi Paul,

    The absolute maximum voltage that the can go on the inputs is 0.5V past the supply rails. It's best practice to only go 0.1V as shown in the recommended electrical characteristics section. 

    The output pins have a diode like-structure connected to the supply pins similarly to the inputs. I'll confirm what the usual rule of thumb is on how far it's ok to go past supply rails. 

    The attached figure is the waveform when DUT is powered on. 

    There is a pulse of U910.8, about 2.317V. 

    So we want to know the voltage spec of U910.8 (TLV9002 pin 8).

    I'm a little skeptical about the output voltage only being 2.317V. The oscilloscope might not have a fast enough bandwidth to capture the incredibly fast transient that occurs right when U26 switches in. These transients can have incredibly high transients. 

    Best Regards, 

    Robert Clifton