As for all switching power supplies, the layout is an important step in the design. Care must be taken in board layout to get the specified performance.
If the layout is not carefully done, the regulator could show poor line and/or load regulation, stability issues as well as EMI problems and interference with RF circuits.
It is critical to provide a low inductance, impedance ground path. Therefore, use wide and short traces for the main current paths.
The input capacitor should be placed as close as possible to the IC pins VIN and GND. The output capacitors should be placed close between VO1/2 and GND pins.
The VO1/2 line should be connected to the output capacitor and routed away from noisy components and traces (e.g. SW line) or other noise sources.