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TPL0102-100: OPAMP output offset

David Huang
Intellectual 2285 points
Part Number: TPL0102-100
Other Parts Discussed in Thread: TLV9054

Hi team,

My customer is currently considering using TPL0102-100 pair with TLV9054 in their design with a use case shown as below.

Offset voltage of random level can be observed at the output of the opamp, where changing the potentiometer's value does not make difference on the offset value.

Here's some questions from the customer:

1. Is it possible that TPL0102-100 is creating this offset as a leakage current and sending to the output?

2. Currently HA pin is left open and ACR register bit6 was set to 1(disable shutdown mode). Is this use case wrong?

Regards,

  • 0
    TI__Mastermind 28518 points

    Hi David, 

    There will be some leakage on the terminals:

     

    Maybe this is what is being seen. Does the offset correspond to a 1uA leakage? 

    The end to end resistance also has a 20% error, and the resistor ladder itself has an offset error in the datasheet that would be present on every code. 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    TI__Intellectual 2285 points

    Hi Katlynne,

    Thanks for the response!

    Is there any ways the customer can use to eliminate this offset? Or maybe using a different part?

    Also, the customer application sets the HA pin open, does this create any difference on this matter(offset)?

    Regards,

  • 0 in reply to David Huang
    TI__Mastermind 28518 points

    Hi David, 

    All of our digipots would have similar errors, so a new device likely wouldn't get rid of the issue completely. 

    The unused terminal in rheostat mode can be connected in two ways. The datasheet leads me to believe there is no difference between the two configurations, and I haven't heard of customer's seeing better performance in one over the other, but I would be interested to know if connecting terminal H to terminal W makes any difference in the offset the customer is seeing.

     

    Is this something they could try easily?

    Best,

    Katlynne Jones