LM5026: Layout for PGND and AGND

Hi Lenna Yan,
It is good practice to keep separate AGND and PGND traces on the PCB, so that sensitive signals like UVLO, RES, TIME, SS, COMP, CS are not disturbed by voltage drops caused by high currents flowing in the power stage GND tracks.
AGND and PGND traces must connect together at one single point on the PCB, usually at the negative terminal of the input capacitor or close to the controller. This ensures that they have the same potential but the currents flowing in the two GND nets are kept separate.
It is important that the two are connected together at some point on the PCB, ideally quite close to the controller, since currents flowing between them through the device, are likely to cause issues.