Datasheet

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Application Circuit
DATA
24
23
22
21
20
19
18
17
16
15
5
6
7
8
9
10
11
12
13
14
PCM1792
BCK
SCK
DGND
V
DD
MS
MDI
MC
MDO
RST
AGND2
I
OUT
R−
V
CC
1
V
COM
L
V
COM
R
I
REF
I
OUT
R+
AGND3R
AGND1
ZEROL
1
2
3
4
ZEROR
MSEL
LRCK
28
27
26
25
V
CC
2L
AGND3L
I
OUT
L−
I
OUT
L+
5 V
V
CC
2R
0.1 µF
Controller
10 µF
3.3 V
PCM
Audio
Data
Source
0.1 µF
10 µF
+
+
47 µF
47 µF
5 V
10 µF
10 kΩ
−
+
C
F
2.7 nF
R
F
1 k
0.1 µF
10 µF
5 V
+
+
+
+
V−
V+
4
12
13
14
−IND
OUTD
−
+
C
F
2.7 nF
R
F
1 k
V−
V+
4
10
9
8
−INC
−
+
C
F
2.7 nF
R
F
1 k
V−
V+
4
3
2
1
−
+
C
F
2.7 nF
R
F
1 k
V−
V+
4
5
6
7
11
11
11
11
−INB
−INA
OUTA
OUTB
OUTC
−
+
1 k
V
CC−
3
4
5
2
LOUT
0.1 F
V
CC+
LIN−
LIN+
0.1 F
R
O
10 
4
−
+
R
F
V
CC−
18
17
16
19
ROUT
0.1 F
V
CC+
RIN−
RIN+
0.1 F
20
1 k
1 k
R
I
R
F
1 k
R
I
1 k
1 k
1 k
R
I
R
F
1 k
R
I
R
F
+
10 µF
0.1 µF
5 V
V+
+
10 µF0.1 µF
−5 V
V−
OPA4134
+
100 µF
10 µF
12 V
V
CC+
+
100 µF10 µF
−12 V
V
CC−
TPA6120A2
+
+
R
O
10 
TPA6120A2
SLOS431 – MARCH 2004
Figure 36. Typical Application Circuit
In many applications, the audio source is digital. It must go through a digital-to-analog converter (DAC) so that
traditional analog amplifiers can drive the speakers or headphones.
Figure 36 shows a complete circuit schematic for such a system. The digital audio is fed into a high performance
DAC. The PCM1792, a Burr-Brown product from TI, is a 24-bit, stereo DAC.
The output of the PCM1792 is current, not voltage, so the OPA4134 is used to convert the current input to a
voltage output. The OPA4134, a Burr-Brown product from TI, is a low-noise, high-speed, high-performance
operational amplifier. C
F
and R
F
are used to set the cutoff frequency of the filter. The RC combination in
Figure 36 has a cutoff frequency of 59 kHz. All four amplifiers of the OPA4134 are used so the TPA6120A2 can
be driven differentially.
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