• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 29 subscribers
  • Views 175 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.

DRV8316REVM: What is the full-scale current value that can be measured?

Kenji
Intellectual 530 points
Part Number: DRV8316REVM

Hi

I’ｍ using DRV8316REVM.
And I want to know about the full-scale current value that can be measured by current sense amplifiers.

From the document, I think full scale current could be calculate as below. Is this correct?

Iout = (Vref / 2 - 0.25) / CSA_Gain
Full-Scale current = 2 * Iout

In case Vref=3.3V, Full-Scale current is as follows,

Gain Iout(A) Full-Scale Current(A)
0.15 9.333 18.666
0.3 4.666 9.332
0.6 2.333 4.666
1.2 1.166 2.333

Also, I have a question about the amplifier output signal (fig, 8-28).
Is this output an inverted output?

  • 0
    TI__Mastermind 21020 points

    Hello Kenji-san,

    Thank you for the question. The full scale current measurement that can be measured by the current sense amplifiers can be found on specifications in the datasheet. You can find this on page 14, I have attached an screenshot below:

    They are rated to handle the max output current of the device which is rated to have a peak output current of 8A for each phase.

    For the question on figure 8-28 on the inverted output, the CSA output is inverted the due to negative feedback in the current sense path. If you notice in the full scale current specification, the min current is stated as the positive 8A values and the max is stated as the -8A value. I hope this answers your questions!

    Best,

    Isaac

  • 0 in reply to Isaac Lara
    Intellectual 530 points

    Hi Lara-san

    I understood about the measurable full scale range of current of the device.

    Now I want to know about the relationship with current sense amplifier output.
    The out of the amplifier will be calculated as I wrote above, right?
    For example, in case of gain=0.15, Iout max and min output range will be 9.333A and -9.333A. 

    However, in actual operation, the output of ± 8A or more cannot be obtained from Iout because
    the measured current range of the device is ±8A.

    Is my understanding correct about the behavior of the device and amplifier?

  • 0 in reply to Kenji
    TI__Mastermind 21020 points

    Hello Kenji-san,

    I am not sure if that is the correct formula for the current sense amplifier output. Let me check with the team and should have an answer for you tomorrow. Thank you for your patience!

    Best,

    Isaac

  • +1 in reply to Isaac Lara
    TI__Mastermind 21020 points

    Hello Kenji-San,

    I apologize for the delay on responding to your question,  but just to verify your assessment on the formula is correct.

    And again that is correct, Iout of more than ±8A cannot be obtained due to the device limits. I hope this helps!

    Best,

    Isaac