Dimming function-2 ADD5203

Dear Sir/Madam,

Our customer is studying with your ADD5203 as LED torch.

So LEDs will be coming on continuously.

And need the dimming function as linear current up and down.

Your datasheet shows 2.9A max current.

And also showed  "LED current adjustable up to 30 mA for each channel" on page-11.

Does this mean the dimming function 2.87A to 2.93A (2.9A +/-30mA) when we put the resister on Rset correct?

Otherwise can we adjust the dimming 0A to 2.9A by 30mA steps??

Thanks Kaos

  • The 2.9A refers to the switch current for the built-in boost converter, not the LED current.

    The LED current is regulated by individual current sources (actually sinks) for each of the eight LED strings that can be attached. These are limited to 30mA per string.

    So if you are looking for a high power LED driver this would not be the correct choice.

    Klaus

  • Hi Klaus,

    Thanks for your reply.

    So we needs 2A current LED driver.

    Also need the dimming function 0A to 2A linear dimming as current regulation not PWM control.

    What is the recommend?

    Thanks Kaos

  • As far as I know, ADI does not have a dedicated LED driver with 2A output current in their product portfolio.

    However, you could easily adapt a switching regulator to do the job with the feedback taken from a current sense resistor. Getting decent efficiency would require a fairly low sense voltage, so you might have to add an amplifier in the feedback loop.

    Klaus

  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:12 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

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