I'm using a SEP8706 IR LED in pairs with a SDP8600 in a label sensing application and I'm trying to control the current of the former. In the past I was using a rheostat in series with a 270 Ohm resistor which was working fine.
So, I thought it would be a good idea to dim my LED using PWM, but using a small resistor in series with the LED and supplying it using the pwm output of a mc didn't quite work, since I need to control the current flowing through the LED, not it's voltage.
Do you think that it's plausible (using a small signal FET maybe) to control the current? Any ideas? The LED has a max Vf=1.7V and max If=50mA.