• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 477 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.

DRV8305: Current Sense Amplifier Gain Error

Blake Ma
Intellectual 955 points
Part Number: DRV8305

Hi,

We have just got question from customer on the current sense amplifier gain error of DRV8305.

From below specification in datasheet, we can get the gain error to be -3%~+3% when input differential >0.025V.

Questions is: when input differential <= 0.025V, what will the gain error be? Can you please share more detailed data for customer's reference?

Thanks for your support!

Best Regards,

Blake Ma

  • 0
    TI__Guru 65390 points
    Blake,

    I will need to see if we have this information available.

    In the meantime, can the customer increase the sense resistor so that the current they wish to measure falls more easily above the 0.025V value?

    Regards,

    -Adam
  • 0 in reply to Adam Sidelsky
    TI__Intellectual 955 points
    Adam,
    Customer has some use case which has input differential <= 0.025V, that's why they are requiring related information from us.
    Please kindly check the more detailed data. Thanks so much!
  • 0 in reply to Blake Ma
    TI__Guru 65390 points
    Blake,

    Talking with the designers, I have an update for you.

    The gain error below 25mV does not change, we expect it to be similar to the datasheet value for the above 25mV case. The reason we spec it this way is because at below 25mV the offset of the CSA starts to interfere and it will be hard to tell how much of the measured error is due to gain error or due to offset error.

    Regards,

    -Adam