TDA7492P

Applications information

Doc ID 15068 Rev 5

21/26

6.5

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-C component values depending on the loud

speaker 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 4-

Ω speaker