I have a few basic questions. I'm thinking about ordering these: https://www.sparkfun.com/products/9264
(2nd pass made to link fixed, moderator)
First, what is forward current (20 mA for each color) vs peak forward current (30 mA)? On the datasheet they appear under "absolute maximum ratings", but I'm assuming 20 mA is what I should be aiming for?
Second, it says it has a voltage drop of 2.0, 3.2, 3.2 V respectively across R,G, & B. How do I take this into account when designing a circuit? Say I have a 5 V power supply, and want to connect 3 of these in parallel (so technically 9 total, since each RGB LED acts as 3 LEDs...?). Does it change the V=IR equation?
Assuming they should each run at 20 mA (if I understood the datasheet correctly like I asked above), does that mean the resistance within each diode would be calculated by:
red: 2 V = 0.02 * R
R = 100 ohms
green & blue (each): 3.2 V = 0.02 * R
R = 160 ohms
Finally, if that IS the case, do I need to take into account those resistance values in the circuit? So:
red: 5V = 0.02 * (R1 + 100)
R1 = 150 ohm resistor is needed
green & blue: 5V = 0.02 * (R2 + 160)
R2 = 90 ohm resistor is needed for each
Or am I totally off? Please help, so confused...