The LDD-350 has input voltage of 9-36V, output voltage of 2-32V and max output current of 350mA.

The LEDs have forward voltage of 2-2.2V and forward current of 280-350mA.

For power consumption, I multiplied 2.2V times 350mA to get 0.77W, then multiplied by eight and added 20% to get 7.4W.

Assuming I only need at least 7.4W, how do I determine the proper voltage for the power supply?