TPS53355: No voltage at output when converting 12V to 3.3V

Hi Experts,

I build a TPS53355 circuit, converting 12V to 3.3V.

The problem is that no voltage at output. I have checked the 12V input power, EN voltage and VREG voltage, all correct. The output loading is about 900mA, no short problem.

The following picture is my circuit according to TI online designer. 

Could you help to suggest how to debug further? what's the potential problem?

Thank you.

Lydia：

您好，

已经收到了您的案例，调查需要些时间，感谢您的耐心等待