tda2075a Tripath Technology Inc., tda2075a Datasheet - Page 15

• Manufacturer Part Number: tda2075a
• Description: Stereo Class-t Digital Audio Amplifier Driver Using Digital Power Processingtm
• Manufacturer: Tripath Technology Inc.

TDA2075A Amplifier Gain
The gain of the TDA2075A is the product of the input stage gain and the modulator gain for the
TDA2075A. Please refer to the sections, Input Stage Design, and Modulator Feedback Design, for a
complete explanation of how to determine the external component values.
For example, using a TDA2075A with the following external components,
Input Stage Design
The TDA2075A input stage is configured as an inverting amplifier, allowing the system designer flexibility
in setting the input stage gain and frequency response. Figure 2 shows a typical application where the
input stage is a constant gain inverting amplifier. The input stage gain should be set so that the maximum
input signal level will drive the input stage output to 4Vpp.
The gain of the input stage, above the low frequency high pass filter point, is that of a simple inverting
amplifier:
15
R
R
R
R
R
A
A
A
A
I
F
FBA
FBB
FBC
INPUT2
VINPUTSTAG
INPUT1
V
V
= 20k:
V
= 20k:
TDA2075A
TDA2075A
TDA2075A
= 1k:
= 1.1k:
= 10.0k:
C
C
I
|
E
I
|
+
+
A



V
R
R
R
20k
20k
R
I
I
R
R
INPUTSTAGE
F
I
F
I
§
¨ ¨
©
R
R
F
R
F
Figure 2: TDA2075A Input Stage
§
¨
©
OAOUT2
OAOUT1
FBC
10.0k
INV1
INV2
R
*
*
FBA
(R
46
45
BIASCAP
1
A
2
1.0k
V
FBA
*
*
TDA2075A
MODULATOR
R
(1.0k

FBB
AGND
+
AGND
+
-
-
*
R
V5
V5
1.1k
FBB

)
1.1k

1
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V
V