OK, another question that I should be able to answer on my own, but I'm not finding what I need. I'm building a control panel and want LED back lights for the switches. There are about 40 switches, and two modes of operation that I want to handle (white or blue) with a "shift" key. LEDs will probably be tiny surface mount devices so around the 4ma current range. Now here seems to be one of the biggest problems, I'm only using 5 volt supply power which seems to mean that I can't put several LEDs in series with each other and have the proper output.
I want to stay away from putting a pile of resistors into this design but if this is the only way, I'll consider it. Size is a little bit of an issue but I should be able to squeeze in an 0603 resistor for each LED in use and I can just use a transitor to turn the power for each back on or off with the shift key.
Also I do not have a data connection to control the driver chip, so it needs an on/off (enable) function. The back lights are simply all white on or all blue on (shift).