TDA8932B NXP Semiconductors, TDA8932B Datasheet - Page 25

• Manufacturer Part Number: TDA8932B
• Description: The TDA8932B is a high efficiency class-D amplifier with low power dissipation
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8932B_4
Product data sheet
14.5 Gain reduction
The 3 dB cut-off frequency is equal to:
Where:
Table 15
or 20 Hz 3 dB cut-off frequency.
Table 15.
The gain of the TDA8932B is internally fixed at 30 dB for SE (or 36 dB for BTL). The gain
can be reduced by a resistive voltage divider at the input (see
When applying a resistive divider, the total closed-loop gain G
Equation 8
Where:
G
Impedance ( )
4
6
8
f
Fig 10. Input configuration for reducing gain
–
v tot
f
R
Cse = single-ended capacitance (F); see
G
G
R
R1 = series resistor ( )
R2 = series resistor ( )
3dB
-3dB
L
EQ
v(tot)
v(cl)
= load impedance ( )
=
= equivalent resistance, R3 and Z
= 3 dB cut-off frequency (Hz)
=
= closed-loop voltage gain, fixed at 30 dB for SE (dB)
= total closed-loop voltage gain (dB)
---------------------------------- -
2
shows an overview of the required SE capacitor values in case of 60 Hz, 40 Hz
G
SE capacitor values
and
v cl
R
1
L
+
Equation
20
Cse
log
Rev. 04 — 18 December 2008
Cse ( F)
f
680
470
330
audio in
-3dB
----------------------------------------- -
R
9:
EQ
= 60 Hz
+
R
R1
EQ
+
R1
R2
R2
i
( )
470 nF
470 nF
Figure 36
f
1000
680
470
-3dB
= 40 Hz
R3
100
k
001aad762
v(tot)
Figure
Class-D audio amplifier
can be calculated by
TDA8932B
f
2200
1500
1000
-3dB
10).
© NXP B.V. 2008. All rights reserved.
= 20 Hz
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(7)
(8)