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TPS61150: Designing an LED Driver with TPS61150DRCR

Shibin Varghese
Intellectual 835 points
Part Number: TPS61150
Other Parts Discussed in Thread: TPS92390

Hi Team,
We want to use an LED driver for one of our projects.
We are using white LEDs.
The forward voltage of the  LEDs can be anywhere between 3V and 3.5V, so we believe a constant current source will be a good choice.
The supply voltage is 6V.
We want to use both the channels of the IC TPS61150DRCR.
Only one LED is needed on each channel.
1). Is such configuration possible with this IC?.
2). What is the best to choose to drive an LED if its forward voltage is unknown?.


  • 0
    TI__Genius 9630 points

    hello Shibin

           I would like to confirm your requirement: Vin=6V, Vo=3V-3.5V with only one LED, 2 channels needed. what about the current rating here? 

          If the above requirement is correct, then I think a buck/buckboost LED driver should be adopted rather than 61150(boost) .

  • 0 in reply to Mason Wang
    Intellectual 835 points

    Hi Mason,
    Thank you for your reply.
    Yes, the forward voltage of the LED will be anywhere between 3V and 4V (3.5V).
    The LED current would be about 20mA per channel.
    Could you suggest to me a buck converter if a buck LED driver is needed for my application?.
    Also, We are using 4*1.5V=6V alkaline batteries for the application.
    The minimum voltage we can expect from such a series configuration is 4*0.9V=3.6V.
    If only a buck converter is used, what will be my output voltage if the battery voltage is close to the forward voltage of the LED?.

  • +1 in reply to Shibin Varghese
    TI__Genius 9630 points

    hello Shibin

           In this case, the input voltage may be higher or lower than the output voltage depending on the battery condition, I propose to use TPS92390 that can support Sepic topology, this device has four channels and can output up to 200mA per channel.