Datasheet

TDA7491HV Application information
Doc ID 14242 Rev 6 37/41
7.6 Reconstruction low-pass filter
Standard applications use a low-pass filter before the speaker. The cutoff frequency should
be higher 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 56 and
Figure 57 below.
Figure 56. Typical LC filter for an 8-Ω speaker
Figure 57. Typical LC filter for a 4-Ω speaker