PAM8301

Filterless Class-D Mono Audio Amplifier

9

09/2008 Rev 1.2

,

Power Analog Microelectronics Inc

www.poweranalog.com

How to Reduce EMI (Electro Magnetic Interference)

A simple solution is to put an additional capacitor 1000 F at power supply terminal for power line coupling

if the traces from amplifier to speakers are short (<20cm).

Most applications require a ferrite bead filter as shown at Figure 1. The ferrite filter depresses EMI of

around 1MHz and higher. When selecting a ferrite bead, choose one with high impedance at high

frequencies and low impedance at low frequencies.

Figure 1: Ferrite Bead Filter to Reduce EMI

μ

220pF

220pF

OUT+

OUT-

Ferrite Bead

Ferrite Bead