PCM1738E2K BURR-BROWN [Burr-Brown Corporation], PCM1738E2K Datasheet - Page 23

• Manufacturer Part Number: PCM1738E2K
• Description: 24-Bit, 192kHz Sampling, Advanced Segment, Audio-Stereo DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

PCM1738
ANALOG OUTPUTS
FIGURE 9. Typical Application for Analog Output Stage.
ANALOG OUTPUT LEVEL AND I/V CONVERTER
The signal level of the DAC current output pins (I
I
Scale). The voltage output of the I/V converter is given by
the following equation:
Here, R
voltage) conversion circuit, R
typical application circuit. The common level of the I/V
conversion circuit must be the same as the common level of
DAC I
+2.5V DC. The non-inverting inputs of the op amps shown
in the I/V circuits are connected to V
common bias voltage.
Op Amp for I/V Converter Circuit
The OPA627BP/BM, or 5534 type op amp, is recommended
for the I/V conversion circuit to obtain specified audio
performance. Dynamic performance, such as gain band-
width, settling time, and slew rate of the op amp creates
audio dynamic performance at the I/V section. Input noise
specification of the op amp should be considered to obtain
120dB S/N ratio.
OUT
SBAS174B
PCM1738E
NOTE: Example R/C values for f
R
C
L–, I
11
23
-R
, C
OUT
18
f
24
OUT
, R
: 5600pF, C
is the feedback resistor in the I/V (current-to-
21
that is given by the V
AGND2
AGND1
I
R+, and I
I
-R
I
I
V
V
V
OUT
MUTE
OUT
OUT
OUT
V
V
V
V
COM
COM
COM
28
I
CC
CC
CC
REF
R+
R–
L+
OUT
L–
: 620 , C
3
2
1
3
2
1
15
28
27
26
25
24
23
22
21
20
19
18
17
16
15
, C
= 2.48mApp • R
OUT
25
11
: 8200pF, C
0.1 F
, C
+
R–) is 2.48mA (p-p) at 0dB (Full
10 F
16k
12
R
10 F
C
, C
1
45kHz.
10 F
11
21
+
, C
, R
16
, C
COM
22
+5.0V
+
12
: not populated, C
17
, R
, C
F
COM
2 reference voltage,
10 F
26
21
, C
2 to provide the
, and R
27
: 1800pF.
(1)
C
C
C
C
11
12
21
22
13
22
, C
OUT
14
on a
,
L+,
or OPA5534 Op Amp
OPA627BP, BM
Analog Gain by Balanced Amplifier
The I/V converters are followed by balanced amplifier
stages that sum the differential signals for each channel,
creating a single-ended voltage output. In addition, the
balanced amplifiers provide a second-order, low-pass filter
function that band limits the audio output signal. The cutoff
frequency and gain is given by external R and C component
values. In the case of Figure 9, the cutoff frequency is 45kHz
with a gain of 1. The output voltage for each channel is 6.2
Vp-p, or 2.2Vrms.
REFERENCE CURRENT RESISTOR
As shown in the analog output application circuit, marked
R
21) to the analog ground, designated as R
the current for the internal reference circuit. The value of R
must be 16k , 1% in order to match the specified gain
error shown in the Specifications table.
1
+
+
-
-
C
C
C
C
R
R
R
R
on Figure 9, there is a resistor connected from I
13
14
23
24
11
12
21
22
R
R
R
R
13
14
23
24
OPA604, OPA2604 Op Amp
OPA134, OPA2134, or
C
C
15
25
R
R
18
28
R
R
R
R
16
17
26
27
R
R
15
25
C
C
C
16
C
26
17
27
1
. This resistor sets
V
L-Channel
V
R-Channel
OUT
OUT
REF
(pin
23
1