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LP8860-Q1: About the accuracy of the current value

Kaji@PAN
Mastermind 7795 points
Part Number: LP8860-Q1

Hi,

I would like to ask you about the accuracy of the current value of LP8860-Q1.
I have set DRV_LED_CURRENT_SCALE [2: 0] to "101" to set the LED current to 100mA.
Moreover, RISET = 24kΩ ± 1% is used.
(Question)
What is the current accuracy for the above settings?
Is it ± 4%, which is the sum of the accuracy of the device itself (± 3%) and the accuracy of the resistance value (± 1%)?
Looking at the thread below, the current accuracy is only guaranteed at 150mA.
Also, if I set it to 100mA and it's not guaranteed, why?

Best regards,

e2e.ti.com/.../627590

  • 0
    TI__Genius 11836 points

    Hi Kaji,

    If you compare the output current to the  ideal value of current equation with 24 kohm, the accuracy will be the root mean square value of all the errors.

  • 0 in reply to Charles-Chen
    Mastermind 7795 points

    Thank you for your reply.
    I will change the content of the question and I will ask you again.
    A thread posted in the past states that ± 3% accuracy is guaranteed only at MAX 150mA.
    It is also stated that the accuracy deteriorates as the current value setting is lowered.
    I would like to know if the accuracy of ± 3% is guaranteed when DRV_LED_CURRENT_SCALE [2: 0] is set to 100mA of "101".
    Is it possible to answer my question?

    Best regards,

  • 0 in reply to Kaji@PAN
    TI__Genius 11836 points

    Hi Sir,

    The accuracy of current is related to the characteristic and accuracy of internal circuit. Therefore,  if you set it to 100mA and it's not guaranteed.