tda2500 Tripath Technology Inc., tda2500 Datasheet - Page 15

• Manufacturer Part Number: tda2500
• Description: Stereo Class-t Digital Audio Amplifier Driver Using Digital Power Processing Dpp
• Manufacturer: Tripath Technology Inc.

TD A 25 00 A MP L IF I ER GA IN
The gain of the TDA2500 is the product of the input stage gain and the modulator gain. 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 TDA2500 with the following external components,
INPUT STAGE DESIGN
The TDA2500 input stage is an inverting amplifier, with a maximum gain of 4. 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. Please note that the
input is biased between V5 and AGND. Thus, the polarity of C
The gain of the input stage, above the low frequency high pass filter point, is that of a simple inverting
amplifier:
15
R
R
A
A
A
A
I
FB
VINPUTSTAG
VTDA2500
VTDA2500
VTDA2500
= 49.9k:
INPUT1
INPUT2
= 18.7k:
|
|
A

E
CI
CI

VINPUTSTAG
4.99k
54.89k

20k
20k
4.99k
:
RI
RI
20k
:

Figure 2: Input Stage
E
:
§
¨
©
R
*
:
19.7k
A
I

§
¨
©
IN2
IN1
V
R
(1.0k
MODULATOR
1020
I
2.5V
4.99K
4.99K
*
20K
20K
:
TDA2500
2.02
1020

AGND
AGND
R
+
-
+
-
V5
V5
FB

* )
1
·
¸
¹
2.02
T r i p a t h T e c h n o l o g y , I n c . - T e c h n i c a l I n f o r m a t i o n
-
14.58

I
must be observed.
1
·
¸
¹
V
V
TDA2500 – KL/ Rev. 0.9/05.05