Why hello great Arduino community! I come before all of you with a problem. I am trying to drive a single common anode LED (http://www.dealextreme.com/p/3w-led-emitter-on-star-multicolored-rgb-4530) with a Li-battery (http://www.dealextreme.com/p/ultrafire-3-7v-18650-2400mah-battery-1213).
The problems I have are: Providing 350ma (or slightly less) in constant current to the LED's three cathodes from a varying voltage source Finding a small component to do this And (this one is not as important because I could use a PNP transistor) a piece that can deliver constant current and dim LEDs based off of PWM (from arduino uno)
When I found this chip (http://www.onsemi.com/pub_link/Collateral/NCP380-D.PDF) I was so excited because I thought I had found what I needed, but then I figured out it can only regulate down to 500ma (150ma more than the max of the LEDs). I know constant voltage + resistors are not the way to go because of thermal runaway, but I'm am new to the world of high power LEDs. I need your help community!
I should also mention that I am tight on space for this project, so the smaller the piece the better!