PMP41037: PMP41037 PCB

Tool/software:

Hi all.

I am building a PMP41037 converter. 

https://www.ti.com/tool/PMP41037

I have had the PCBs from the documentation fabricated. What I'm wondering about is the circuit board circled in this image.

I can't find any info about it in the documentation. Does anyone know what this board is? Thanks.

Mark Smart

CU Aerospace

Champaign, IL, USA