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.

[FAQ] How to estimate the maximum output current of the LED backlight driver?

Genius 13375 points

Replies: 1

Views: 513

Hi TI Engineer,

     When I'm choosing a LED backlight driver(with internal MOSFET), I don't know how to know whether the part can support my application based on my configuration, and I don't know how much current that can drive? Can you provide the method to estimate the maximum output current? Thanks.

1 Reply

  • Hi,

        Most backlight driver were based on Boost +FB or Boost + Current Sink topology.

        For LED backlight driver with internal MOSFET, datasheet only provides the maximum current per channel( for boost + current sinks topology) or feedback voltage(for boost + feedback topology). You need to use the detail application specs and internal current sinks to calculate the maximum output current.(note: we don’t consider the thermal issue now).

        Here we give an TPS61165 example to show how to estimate the maximum output current of the LED backlight driver. This mathod is suitable for all kind of boost led backlight driver with internal MOSFET.

        1. we need to know the detail specs:    

        2. We can calculate the inductor peak to peak current ripple.

        3. Then we can calculate the maximum Iout.

        Below is the example for TPS61165:

        

        And we can also know the trend when change the input voltage or output volatge as below:

        

         May this method can help you. And I also upload the Mathcad file as below:

         How to calculate the maximum output current.xmcd

    Regards

    Sean

             

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.