TPS92641EVM: Test TPS92641EVM about LED shunt dimming issue

Part Number: TPS92641EVM

Hi, TI experts! 

TPS92641EVM-Shunt dimmer-5us-200mA.jpg

I am using the TPS92641EVM to conduct a LED shunt dimming test.

The test conditions and setup are as follows:

(1)Input Voltage: 43.5V,LED Load: 32V / 1A

(2)Connection: 10-meter cable is connected between the LED and the TPS92641EVM.

(3)SDIM Input: 100:1 PWM signal (f = 2 kHz)

(4)Shunt MOSFET: FKD4014 driven by the SDRV pin

Currently, I am unable to successfully achieve a target current pulse width of 5us at 200 mA.

Could you please help check my setup and advise on what modifications or adjustments are required to resolve this issue?

Thank you!