Applications information

TDA7498L

22/27

Doc ID 16504 Rev 3

5.6

Output low-pass filter

To avoid EMI problems, it may be necessary to use a low-pass filter before the speaker. The

cutoff frequency should be larger than 22 kHz and much lower than the output switching

frequency. It is necessary to choose the L and C component values depending on the

loudspeaker impedance. Some typical values, which give a cutoff frequency of 27 kHz, are

shown in Figure 25 and Figure 26 below.

Figure 25.

Typical LC filter for a 8-

Ω speaker

Figure 26.

Typical LC filter for a 6-

Ω speaker