Recommend a four-layer or six-layer PCB for good
thermal performance and with maximum ground plane. 3" × 3", four-layer PCB with
2-oz. copper used as example.
Recommend having equal caps on each side of the IC. Place them right across VIN as close as possible.
Inner layer 1 is ground with the PGND to AGND net
tie
Inner layer2 has VIN copper pour that has vias to
the top layer VIN. Place multiple vias under the device near VIN and PGND and
near input capacitors to reduce parasitic inductance and improve thermal
performance
Bottom later is GND with the BOOT trace routing.
Reference feedback to the quite AGND and routed
away from the switch node.
Make VIN trace wide to reduce the trace
impedance.