LM3410: LM3410

Hi,

I have the same question. Now I want to drive 4 series LEDs (Vfw=3.3V for each)  with LM3410 at 500mA, the input power is 3-5V,  I cannot get simulation result in webench, the reason is: the duty cycle is exceeding the limit. 

If I change the output current to 0.3A, I've got the result.Does it mean I cannot use the LM3410 to drive 12V@0.5mA ?

Bo