I'm currently working in a project where I need to control the intensity of 24 high power LEDs in 5 levels. I'm planning to use LumiLeds L1CU-BLU1000000000 (https://www.lumileds.com/uploads/705/PB198-pdf) where the cut-off voltage is 2.83 volts and current is 350mA. As per the requirements, the power supply should be from an SMPS ( maximum output - 12v,6A).
I need to select a constant current driver with PWM facility ( 0-5v max ) to control the LED intensity from a micro-controller. What type of driver IC will be best suit for this application?
What I know so far is:
- I can use a constant current boost converter IC with PWM ( input-12v,3A max and output 23v,1.3A) and connect 8 leds in series and 3 such strips in parallel so that each parallel branch would get around 350mA and each LED in the strip would get around 2.8V. In this case I need only one PWM channel from micro-controller to dim all LEDs at a time. If someone could suggest a driver IC for this specification it would be great.Are there any hidden flaws in this Idea or is it less efficient in terms of power consumption?
- I can use a constant current buck converter IC with PWM ( input 12V, 3A max and output 9.5V,2.8A) and connect 3 LEDs in series and 8 such parallel strips. Each series strip gets around 350mA and each LED gets around 2.8v (with some resistors added to each series branch)
If I'm using 3 driver ICs and dividing up the LED load among those, is it still okay to use 3 pwm channels from the micro-controller for dimming all the LEDs simultaneously? I'm planning to use STM32f4 series micro-controller in my project, I hope that it can drive 3 PWM channels at a time.
I've searched and found one IC, but still I doubt whether it will suit my application or not.
