Applications information

TDA7492

26/32

DocID014926 Rev 6

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 33 and Figure 34 below.

Figure 33. Typical LC filter for a 8-

 speaker

Figure 34. Typical LC filter for a 4-

 speaker