I have a project where a PCB has been manufactured with an error, where a 3 lead BI color LED (red/blue) has a single resistor to limit the current for both colors. I can fix this by hacking apart the PCB but I would like to know what resistor value I could potentially use to satisfy both the RED and BLUE colors of the LED.
This is the datasheet for the LED: http://www.unique-leds.com/images/datasheets/CG/D3009R1B2SBDC.pdf
As per the datasheet the RED has a min/max forward voltage for 1.9/2.5 while the blue has a min/max of 2.9/3.5 If I were to take an average of the mins and maxes and then the average of that:
((1.9+2.9)/2) = 2.4v min ((2.5+3.5)/2) = 3.0v max ((2.4+3.0)/2) = 2.7v averages
and use this to calculate the resistance needed to satisfy both colors:
R = (5v-2.7v)/0.02a R = 115ohms
Would this be the correct approach to solve my problem or is there a different way I should go about this. Is this even possible without negatively effecting one LED color or the other?
I can manage two separate resistors if I tear up the solder mask and hack it until it works but if I can use the already provided through hole it would make life easier.
Overall I am asking what is the best way to calculate the resistance that would satisfy two colors, RED and BLUE,in a single LED package with 3 leads using a single resistor.
Thank you for your time.