9 Power Supply Recommendations

All power (high-current) traces should be as thick and short as possible. The inductor and output capacitors should be as close to each other as possible. This reduces EMI radiated by the power traces due to high switching currents. In a two-sided PCB, TI recommends having ground planes on both sides of the PCB to help reduce noise and ground loop errors. The ground connection for the input and output capacitors and IC ground should connect to this ground plane. In a multi-layer PCB, the ground plane separates the power plane (where high switching currents and components are) from the signal plane (where the feedback trace and components are) for improved performance. Also, arrange the components such that the switching-current loops curl in the same direction. Place the high-current components such that during conduction the current path is in the same direction. This prevents magnetic field reversal caused by the traces between the two half-cycles, and helps reduce radiated EMI. Route the feedback trace such that there is minimum interaction with any noise sources associated with the switching components. The recommended practice is to ensure the inductor is placed away from the feedback trace to prevent creating an EMI noise source. Do not locate the sensitive components and their traces near any switching nodes or high-current traces.