Led driver for PWM-controlled power supply
A PWM-controlled power supply 48V is provided in an existing lighting application.
Until now, the LEDs have been driven with a linear constant current source. To increase efficiency, we would like to use a DC/DC LED driver instead.
Dimming would continue to be realised with the output of the same power supply unit. The PWM frequency is in the range of 500Hz-5kHz
Is there an LED driver that can be supplied from a PWM-controlled power supply?
Hello Phillip, welcome to the MPS Forums!
For your application, you will want to focus on an LED driver that can handle dimming via a PWM signal that would come from your power supply while improving upon the efficiency in comparison to the constant linear current source. What is the output current range you are trying to drive?
For now, here are some options that MPS has to choose from:
Look the datasheets of these parts over and let us know what you think.
Best,
Krishan
Thanks for your reply, Krishan!
I’ll take a closer look at the datasheets of your suggestions.
We would have 6 white leds (~3VDC each) in a row per driver. The LED current would be around 80mA. Cost efficiency is also crucial for us.
Since we are dimming with the supply voltage of the driver and not via the dimming function of the driver itself, I think the driver should have low start-up times to allow higher PWM frequencies and low duty cycles.
Based on the above information, would any of your suggestions be more suitable for the application?
Best,
Philipp
Hello again Phillip,
Thanks for providing more information of your application. The MP24833-A seems to fit your requirements and also appears to provide some headroom on your current for the LEDs you have as well.
However I understand that cost is a factor for any project despite having a good part that works. So 6 x 80mA means you’ll need at minimum to drive 480mA, so any of the parts that I listed should work well. It would just be a matter of seeing which one works well in terms of cost.
Best,
Krishan