TPS56637: Design questions by customer

Part Number: TPS56637 Hello, I have a customer asking the following: In my new design I use DC/DC (12V to 1V/6A) TPS56637RPAR. According to Datasheet and Evaluation Board Guideline The AGND should be designed separated from PGND and connected at one point. Are this must or as a option? What purpose of this recommendation? Is this recommendation could be to my detriment when used 8 layers PCB and many high speed ICs? Thermal problems? Report_12V_to_1V_5A.pdf Thanks in advance

Hi, it is not a must, but doing this is just helpful to provide a clean reference ground for quiet analog signal.so it is recommended, not related to thermal performance. Yuchang