High Power Led Driver
Arduino Controlled Analog Dimmed Led Driver
Using IS31LT3360-SDLS3-TR (constant Current Led driver) and MCP4728T-E/UN (I2c D/A Converter)
PCB Files
http://www.megafileupload.com/vMcL/led_shield_new.sch
http://www.megafileupload.com/zYlO/led_shield_new.brd
Its very adaptable to your needs , just take a look at the 2 datasheets and the schematic.
You can leave U1 free if you dont want to supply your arduino with the same Source.
