The Importance of PCB Layout Design

PCB Layout for a Switching Power Supply is as Important as Circuit Design

In designing a switching power supply, the PCB layout design is, like the circuit design, very important. If the PCB layout is not appropriate, not only is the inherent performance of the power supply IC impeded, but operation may be abnormal. In not a few cases, problems arising during prototyping of a switching power supply originate in the PCB layout.

Problems arising from PCB layout include noise (including spikes and oscillations), deterioration of regulation, and unstable operation. In particular, noise is closely related to conformance to recent EMC regulations. In many cases, such problems can be resolved through an appropriate PCB layout.

Examples of the circuit diagram and PCB layout diagram of a BU33UV7NUX-EVK-101 evaluation board for the BU33UV7NUX synchronous rectifying step-up DC-DC converter, as well as an actual board.
*The PCB layout diagram does not include the jumper patterns, terminals, or other features included in evaluation boards.