Reducing EMI in Class D Audio Applications: The Basics

Presentation w/ Transcript (pdf 493KB)

This web seminar gives an overview of Electro-Magnetic Interference in Class D Audio applications and some practical ramifications for the audio designer. It is intended as the first part in a series of webinars to provide information to handle the growing impact of EMI/EMC issues, with a focus on audio applications. Consumer audio and portable applications, with space constraints growing ever more stringent, will have particular relevance.

The seminar will first provide a summary of the terminology and some key points necessary to understanding the phenomenon of EMI. The next section will describe the Class D Audio Amplifer, its emergence as one of the most popular amplifier topologies, and its impact on radiated and conducted emissions for the circuit designer. The seminar then covers some practical guidelines of dealing with the Class D topology with regards to EMI in a circuit design. The final section wraps up with National's ongoing efforts to create a 'Quiet' Low-EMI Class D Amplifier.

Topics covered in this online seminar include:

• What is EMI?
• The Class D Audio Amplifer
• Dealing with EMI - Practice and approaches
• Creating a 'quiet' Class D building block