I'm looking at using an IN-S85AT5UW in an upcoming hobby project. I'm pretty sure it says that with the white LED, I'll get about 180 mcd and that the maximum continuous forward current is 5ma.
That feels surprisingly low, so I thought I'd get a sanity check. It also kind of makes the forward voltage range a bigger concern I think.
I have a 5V supply and if the LED has a typical forward voltage between 2.6 and 3.4, then I'll have to drop 2.4V to 1.6V across a current limiting resistor.
So, somewhere between 320 and 480 ohms? That seems like a pretty big range. If I get an LED with a forward voltage of 2.6V and I have a 320 ohms resistor, then I'll have a 7.5ma current . . . which is 50% higher than the rated forward current.
Do I pick conservatively and accept the loss in brightness? Do I pick a resistor based on the nominal forward voltage of the LED (3V) and hope I don't burn out the LED? Are the datasheets written so that if you select components at nominal values, the component will not burn out over its rated min/max range?