Layout Guidelines For TPA300x Series Parts

This article provides a well-reinforced procedure for the PCB layout task as it pertains to the TPA300x series of class D amplifiers. This information can also be used in the layout of the TPA200x series, or any other class D audio amplifier. This task needs a logical sequence. If we simply jump into the layout task, without understanding how the circuits work, we risk not having an optimal end result. Whether the design engineer does the layout on his or her own or hands the layout task off to the appropriate PCB specialist, there needs to be a clear understanding of the fundamentals of the circuit on the designer's part. As is true in most any engineering practice, there is no unique solution to a given problem. In this case, there is no unique solution to a given layout. However, several unique steps should be followed in order to achieve an optimal solution. This article has four major parts. The first is the power train analysis and output inductor specification section. This is the most important section as well as the most involved. Second,there is a brief section on noise and grounding. Third, there is a detailed section on the component placement and layout tasks. The fourth section is an EMI mitigation example performed on the same principles illustrated in this document. From front to back this should be a two hour read. More importantly before, throughout, and after the process of building the end product, this application note serves as a reference to the designer.