Yes, I am suggesting a led driver IC because the schematic for the whole circuit is already there in the datasheet, and a few pages further the datasheet explains how the chip works and how to choose the parts around the chip.

Resistors just won't work for this application, because the current is too high and the voltage drop is also too high.

Here's some basic lesson about limiting currents in led.

Leds has forward voltage (let's say 2.7v) and maximum current (350mA). In order to have only 2.7v reach the led, the difference between the input voltage and this 2.7v has to disappear and that's why you put a resistor in series with the led.

The formula to is simple : Vinput - Forward Voltage LED = Resistance / Current ... so Resistance = (Vin - Vled) / Current .. in your case, it's (15v - 2.7v) / 0.35A = 35.14 ohm

The power dissipated in the resistor will be equal to P = IxIxR = 0.35x0.35x35.14 = 4.3 watts. So it would be wise to use a resistor rated for 7w or 10w, just so that it wouldn't overheat. Even so, with 4w dissipated, the resistor will probably be quite hot.

Alternatively, you can use several resistors in series instead, for example 4x 8-10 ohm resistors each with a 3w rating.

But you'd still have two problems:

1. as the resistor heats, the resistance will change slightly, usually the resistance will decrease, which means the current going through the led will go up. You can counter this by picking a much higher resistor in the first place (ex use above formulas using 330mA instead of 350mA, to leave 20mA as a safety margin)

2. as the LED itself heats up, the forward voltage will change... for example let's say instead of 2.7v it will be 2.5v ... so now if you go again through the formula, you have 35.17 ohm instead of 35.14 ohm if you do the math for 350mA ... even more if you play it safe for less current.

A LED driver only needs a couple of carefully chosen parts (how to pick them is written in the datasheet) and gives you about 85-95% efficiency, and the chip will constantly monitor the current going through the led and will keep it 350mA no matter how the forward voltage fluctuates, and there's no resistor to waste a few watts on, and make extra heat.