DLP5530Q1EVM: DLP5530Q1EVM LED driver current problems

Hi!

We buy a DLP5530Q1EVM, and powered on ,It should be functioning normally so far.However, there were some confusing problems about LED driver currents  in the test.

1、In the schematic diagram, the default LED voltage of DLP5530Q1EVM is 8V, and the current limit is 8A. However, it is found that the maximum current of RGB LED does not exceed 3A after power on.and 

During the LED modulation turn-on Ton time, the current of the LED is zigzag change, just as introduced in the LM3409 specification book, and the measured waveform is shown in Figure.

I want to know why the LED current waveform is like this?

Why isn't the current waveform like DLP4710 or DLP3310, which is flat?

LED RED Current  waveform                                                                                         LM3409 datasheet LED current

2、In test，We refer to DLP5530PGUQ1EVM Light source used，use LED as follow，we found that It works fine.

but the LED VF voltage are 1.4A/2.9V max, 1.4A/3.5V max,1.4A/3.5V  max,

so,As in the kit, the supply voltage is 8V, so it is no problem to use this. Is the initial setting of the current made in the kit?

and Where to set the current On our own?

3、For HUD display，  Where RGB LED regulation Duty cycle can be seted? and  Whether  the sum  of R、G、B duty cycle  is satisfied 100% percent？

thanks！