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TFA9812_2 © NXP B.V. 2009. All rights reserved.
Preliminary data sheet Rev. 02 — 22 January 2009 51 of 66
NXP Semiconductors
TFA9812
BTL stereo Class-D audio amplifier with I
2
S input
Remark: A 4.8 Ω speaker (6 Ω speaker with 20 % spread) in BTL configuration can be
used up to a supply voltage of 17 V without running into current limiting. Current limiting
(clipping) will avoid audio holes, but it causes a distortion comparable to voltage clipping.
14.3 Speaker configuration and impedance
For a flat-frequency response (second-order Butterworth filter) it is necessary to change
the low pass filter components L
LC
and C
LC
according to the speaker configuration and
impedance.
14.4 Typical application schematics
Table 58. Filter component values
Impedance (Ω) L
LC
(µH) C
LC
(nF)
6 15 680
8 18 560
16 47 330