TDA749213TR Datasheet, PDF (26/32 Pages) STMicroelectronics – 50 W + 50 W dual BTL class-D audio amplifier

Applications information
TDA7492
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-Ω speaker
Figure 34. Typical LC filter for a 4-Ω speaker
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Doc ID 14926 Rev 5