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CRAMF.1
Associate
July 29, 2022
Question

I am planning to use the STEVAL-ILL078V1 board for driving infra-red LEDs. Components will be changed to match values in the attached eDesignSuite printout. Would it be possible to replace "Rlim" with a digital potentiometer to make changes on the fl

  • July 29, 2022
  • 1 reply
  • 876 views
    This topic has been closed for replies.

    1 reply

    Peter BENSCH
    Technical Moderator
    August 8, 2022

    Welcome, @CRAMF.1​, to the community!

    Yes, you can also use a polycrystalline digital potentiometer as a RILIM instead of a fixed resistor. The important thing is that it is a real ohmic resistor and not a semiconductor junction whose behaviour may not be suitable.

    However, please keep an eye on the non-linear characteristic of ISKIP current vs. RILIM, so that you do not overload the IRLED.

    Does it answer your question?

    Regards

    /Peter

    CRAMF.1
    CRAMF.1Author
    Associate
    August 9, 2022

    Hi Peter,

    Thank you for confirming. I was waiting for your reply before looking into the details of the resistive properties provided by digital potentiometers. If the latter do not come with ohmic output resistances then I might look at using a 1x8 multiplexer connected to a various resistances. I am currently busy with another project and I may get back to you if I have additional questions regarding the ISKIP parameter you have mentioned below. Thank you for the heads-up!

    Chundra Ramful, P.Eng.

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