On the LED being run from a PWM source.

If strobing is an issue, a capacitor could be added in parallel to the output to smooth things out. Depending on how large the cap is and max current availible from the PWM unit, a resistor might need to be added in series to the cap to limit charging inrush current when things are turned on.

( The resistor might be needed because a capacitor looks like a dead short until it charges up. )