TDA7498

Applications information

Doc ID 16107 Rev 8

23/28

4.6

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

loud-speaker impedance. Some typical values, which give a cutoff frequency of 27 kHz, are

shown in Figure 24 and Figure 25 below.

Figure 24.

Typical LC filter for a 8-

Ω speaker

Figure 25.

Typical LC filter for a 6-

Ω speaker