I'm doing a DC-DC buck converter routing, using TPS62130. As known, the key point to route a DC-DC converter is to reduce the current loop area. In my design, I have a dedicated ground plane, so I have two choices to close the current loop:
- The left one, the loop is closed on the top layer.
- The right one, the loop is closed through vias, and the current flows on the ground plane and return through the thermal vias back to the PGND of the chip.
In the graph, the biggest component is the output inductor, and there are two output capacitors in parallel at the right end of the inductor. The only difference is: The left one, no current will flow on the ground plane. But the right one, the current will go through vias and flow on ground plane, then return to top layer. Which one is better?