I am looking for an LED driver that can drive four (4) blue LEDs, each at a DC current of 5mA. Forward voltage at 5mA is 2.8V typical (3.4V max). Due to variations in input voltage from the vehicle (8-32V), I was thinking of doing 4 separate channels running off the 5V rail. I need constant-current control and also the ability to dim the LEDs.
Does anyone have any recommendations for this application? I was looking at TLC5916/5917 for this application as it had analog dimming and was showing a 3mA to 150mA range. Is the 3mA minimum range in reference to the maximum DC current (5mA in our application)? Or does the DC current level even during analog dimming have to remain above 3mA? If the latter, with a minimum dimming of 1/12th, I assume this would mean the max DC current would need to be ~28mA to stay above the minimum of 3mA and this device would not work in our application.