The TDA8933B is a high-efficiency class D amplifier with low power dissipation

TDA8933B

Manufacturer Part NumberTDA8933B
DescriptionThe TDA8933B is a high-efficiency class D amplifier with low power dissipation
ManufacturerNXP Semiconductors
TDA8933B datasheet
 
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NXP Semiconductors
14.4 Single-ended capacitor
The SE capacitor forms a high-pass filter with the speaker impedance. This means that
the frequency response will roll off with 20 dB per decade below f
frequency of 3 dB.
The 3 dB cut-off frequency is equal to:
f
=
3dB
Where:
f
3dB
R
= load resistance (W)
L
C
SE
Table 15
40 Hz or 20 Hz 3 dB cut-off frequency.
Table 15.
Impedance ( )
4
6
8
14.5 Gain reduction
The gain of the TDA8933B is internally fixed at 30 dB for SE and 36 dB for BTL. The gain
can be reduced by a resistive voltage divider at the input (see
Fig 9.
When applying a resistive divider, the total voltage gain G
Equation 8
G
=
v tot
Where:
G
v(tot)
G
v(cl)
R
EQ
TDA8933B_1
Preliminary data sheet
1
---------------------------------- -
2
R
C
L
SE
= 3 dB cut-off frequency (Hz)
= single-ended capacitance (F); see
shows an overview of the required SE capacitor values in the case of a 60 Hz,
SE capacitor values
C
( F)
SE
f
= 60 Hz
3dB
680
470
330
R1
audio in
R2
Input configuration for reducing gain
and
Equation
9:
R
EQ
G
+
20
log
----------------------------------------- -
v cl
R
+
R1
+
R2
EQ
= total voltage gain (dB)
= closed-loop voltage gain, fixed at 30 dB for SE (dB)
= equivalent resistance, R3 and Z
Rev. 01 — 23 October 2008
TDA8933B
Class D audio amplifier
and a cut-off
3dB
Figure 32
f
= 40 Hz
f
= 20 Hz
3dB
3dB
1000
2200
680
1500
470
1000
Figure
9).
470 nF
100
R3
k
470 nF
010aaa137
can be calculated using
v(tot)
(
i
© NXP B.V. 2008. All rights reserved.
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