Datasheet


SLES071B − MARCH 2003 − REVISED NOVEMBER 2006
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34
APPLICATION INFORMATION
ANALOG OUTPUTS
–
–
SCK
24
23
22
21
20
19
18
17
16
15
5
6
7
8
9
10
11
12
13
14
PCM1791A
RST
V
DD
DGND
AGNDF
V
CC
R
AGNDR
V
OUT
R–
V
OUT
R+
V
COM
MSEL
V
OUT
L–
ZEROL
ZEROR
V
CC
F
V
CC
L
V
OUT
L+
AGNDC
AGNDL
LRCK
1
2
3
4
BCK
DATA
MUTE
28
27
26
25
MS
MC
MDI
MDO
V
CC
C
+
1 µF
+
C
3
L
R
6
L
R
4
L
R
5
L
C
1
L
C
2
L
R
3
L
R
2
L
R
1
L
V
OUT
L-Channel
+
5 V
+
V
OUT
R-Channel
10 µF
0.1 µF
C
3
R
R
6
R
R
4
R
R
5
R
C
1
R
C
2
R
R
3
R
R
2
R
R
1
R
NOTE
:
Example R and C values for f
C
= 77 kHz – R
1
, R
2
: 1.8 kΩ, R
3
,R
4
: 3.3 kΩ, R
5
,R
6
: 680 Ω, C
1
: 1800 pF, C
2
, C
3
: 560 pF.
Figure 36. Typical Application for Analog Output Stage
Analog Output Level and LPF
The signal level of the DAC differential-voltage output {(V
OUT
L+)–(V
OUT
L–), (V
OUT
R+)–(V
OUT
R–)} is 3.2 Vp-p
at 0 dB (full scale). The voltage output of the LPF is given by following equation:
V
OUT
= 3.2 Vp-p × (R
f
/R
i
)
Here, R
f
is the feedback resistor in the LPF, and R
3
= R
4
in a typical application circuit. R
i
is the input resistor
in the LPF, and R
1
= R
2
in a typical application circuit.
Operational Amplifier for LPF
An OPA2134 or 5532 type operational amplifier is recommended for the LPF circuit to obtain the specified audio
performance. Dynamic performance such as gain bandwidth, settling time, and slew rate of the operational
amplifier largely determines the audio dynamic performance of the LPF section. The input noise specification
of the operational amplifier should be considered to obtain a 113-dB S/N ratio.