AD1865 Analog Devices, AD1865 Datasheet - Page 8

• Manufacturer Part Number: AD1865
• Description: Complete Dual 18-Bit 16 x Fs Audio DAC
• Manufacturer: Analog Devices

AD1865
18-BIT CD PLAYER DESIGN
Figure 10 illustrates an 18-bit CD player design incorporating
an AD1865 D/A converter, an NE5532 dual op amp and the
SM5813 digital filter chip manufactured by NPC. In this de-
sign, the SM5813 filter transmits left and right digital data to
both channels of the AD1865. The left and right latch signals,
LL and LR, are both provided by the word clock signal
(WCKO) of the digital filter. The digital filter supplies data at
an 8
The digital data is converted to analog output voltages by the
output amplifiers on the AD1865. Note that no external compo-
nents are required by the AD1865. Also, no deglitching cir-
cuitry is required.
F
13
14
10
11
12
2
4
5
6
7
8
9
1
3
S
oversample rate to each channel.
VS
SM5813AP/
S1
APT
WCKO
OW20
OW18
BCKO
DOR
DOL
VS
V
DG
DD
S2
28
27
26
25
21
20
19
18
15
24
23
22
17
16
+5V DIGITAL
SUPPLY
–5V ANALOG SUPPLY
C1
Figure 10. Complete 8
11
10
12
1
2
3
4
5
6
7
8
9
TRIM
MSB
AGND
R
V
DR
LR
CLK
–V
I
SJ
+V
OUT
F
OUT
S
L
AD1865
AGND
DGND
TRIM
V
MSB
I
+V
OUT
OUT
NC
DL
SJ
R
LL
S
F
24
23
20
19
17
22
21
18
16
15
14
13
–8–
+5V ANALOG SUPPLY
An NE5532 dual op amp is used to provide the output antialias
filters required for adequate image rejection. One 2-pole filter
section is provided for each channel. An additional pole is cre-
ated from the combination of the internal feedback resistors
(R
nominal 3 k R
place a pole at approximately 147 kHz, effectively eliminating
all high frequency noise components.
Low distortion, superior channel separation, low power con-
sumption and a low parts count are all realized by this simple
design.
C2
F
S
F
) and the external capacitors C1 and C2. For example, the
18-Bit CD Player
F
with a 360 pF capacitor for C1 and C2 will
1
3
2
4
–V
S
NE5532
+V
S
8
7
6
5
LEFT
CHANNEL
OUTPUT
RIGHT
CHANNEL
OUTPUT
REV. 0