My goal is to drive an infrared LED like (this SFH 4727AS) to control IR remote controlled devices (for example a TV).
I can already output the signal on a pin of my microcontroller. The signal has a carrier frequency of 38kHz.
I am however limited to a 5V 1A power supply and would like to drive the LED as close to the 5W psu limit as possible.
I first thought about using a MOSFET like this AO3400A together with a resistor, but decided it was worth using an LED driver, do you agree?
Now I'm looking at this PAM2804 constant current LED driver but I'm not sure if I can just supply my signal to the EN pin. The EN pin is meant for PWM-dimming, so does that mean the output is smoothed to prevent flickering?
I'd love to hear your thoughts about how I should go about this.
Thanks
Hey, thanks for your comment. I looked at using a resistor in series with the LED, but if my calculations were correct I could only power the LED less than 3W and 2W would be wasted.
R = (V~s~-V~f~)/I~f~ = (5V-2.8V)/1A = 2.2Ω
P~LED~ = V~f~*I~f~ = 2.8V*1A = 2.8W
P~Resistor~ = V~s~*I~f~-P~LED~ = 5V*1A-2.8W = 2.2W
Let me know if the calculations are correct.
Edit: Calculations