AD1843JS Analog Devices Inc, AD1843JS Datasheet - Page 57

• Manufacturer Part Number: AD1843JS
• Description: IC CODEC STEREO 5V 16BIT 80PQFP
• Manufacturer: Analog Devices Inc
• Type: Stereo Audior

Specifications of AD1843JS

• Rohs Status: RoHS non-compliant
• Data Interface: Serial
• Resolution (bits): 16 b
• Number Of Adcs / Dacs: 1 / 2
• Sigma Delta: Yes
• S/n Ratio, Adcs / Dacs (db) Typ: 92 / 86
• Dynamic Range, Adcs / Dacs (db) Typ: 85 / 80
• Voltage - Supply, Analog: 4.75 V ~ 5.25 V
• Voltage - Supply, Digital: 2.85 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 80-MQFP, 80-PQFP

REV. 0
Figure 27 illustrates reference bypassing. V
connected to its bypass capacitors. The 10 F capacitor should
be tantalum, and the 0.1 F capacitor should be ceramic. Figure
27 shows an optional voltage follower buffer on the CMOUT
signal. The output of this buffer, CMBUF, can be used in any
circuit which needs the common-mode bias point from the
AD1843’s on-chip voltage reference. The AD820 is a JFET in-
put op amp whose very high impedance inputs present essen-
tially no load on the CMOUT output from the AD1843.
Figure 28 illustrates the signal-path filtering capacitors, FILTL
and FILTR, connections to analog ground. The 1.0 F capaci-
tors required by the AD1843 can be of any type.
Figure 29 illustrates the antialias filtering capacitors, AAFILTL
and AAFILTR, connections to analog ground. The 1000 pF
capacitors must be NPO types.
The 24.576 MHz crystal shown in the crystal connection cir-
cuitry of Figure 30 should be fundamental-mode and parallel-
tuned. Note that using the exact data sheet frequency is not
V
Figure 29. AD1843 Antialias Filter Capacitor Connections
Figure 28. AD1843 External Filter Capacitor Connections
REF
10µF
Figure 27. AD1843 Voltage Reference Bypassing
MOUT
Figure 26. AD1843 Mono Output Circuit
CMBUF
10k
0.1µF
1000pF
1.0µF
CMOUT
NPO
AD1843
OP279
LOUT2LN
LOUT2LP
AAFILTL
10k
1/2
FILTL
XCTL0
LINLP
10µF
SN74HC14
3
U3B
OPTIONAL
AAFILTR
4
FILTR
0.1µF
16
SN74HC14
1
C3 100nF
C2 100nF
C1 100nF
U3A
1.0µF
1000pF
NPO
470µF
2
OPTIONAL BUFFER
REF
Figure 32. Cermetek DAA Example Circuit
+ C7
DV
4.7µF TANT
(OPTIONAL)
8
6
5
3
4
DD
R1
100k
should only be
AD820
XMIT+
XMIT–
RCV
OFFHK
RT
1/2
TO PC
SPEAKER
CERMETEK
CH1837
DAA
DV
GND
9
SN74HC14
V
9
CC
DD
U3D
C4 100nF
RING
8
TIP
SN74HC14
5
CMBUF
1
U3C
2
MOV
VR1
MOV
VR2
GROUND
6
EARTH
TO DSP OR HOST
–57–
CPU INTERRUPT
VR3
MOV
IRQ
required and that external clock sources can be used in place of
the AD1843’s internal oscillator. If using an external clock
source, apply it to the crystal input pin (XTALI) while leaving
the crystal output pin (XTALO) unconnected. Attention
should be paid to providing a low-jitter external input clock.
Ideally, there should be no greater than 5 ns rms of random
(white) phase jitter to ensure that it does not significantly de-
grade the SNR of the AD1843.
Figure 31 and Figure 32 show example circuits for a Data
Access Arrangement (DAA). These circuits are shown as
examples only; DAA circuits are subject to regulatory approval
since they connect directly to the Public Switched Telephone
Network (PSTN).
PHONE
CURRENT
CURRENT
LIMIT
LIMIT
F1
F2
SINGLE
Figure 31. Silicon Systems DAA Example Circuit
NOTES:
1. VR1,2,3. OVER VOLTAGE AND LIGHTNING PROTECTION
2. C5,6. EMI/RFI SUPPRESSION. HIGH VOLTAGE DISK
3. F1,2. CURRENT LIMITING DEVICES. RAYCHEM POLY FUSE,
4. L1,2. EMI/RFI SUPPRESSION. FERRITE BEADS, FAIR-RITE
5. J1. FCC APPROVED RJ-11 JACK. REF FCC PUBLIC NOTICE #42269
RJ11
INDICATION
MOV SIDACTORS. AVAILABLE AS A SINGLE UNIT FROM
TECCOR, PART NUMBER P3203AB OR P3203AA.
CERAMIC CAPACITORS, 1nF 1.5kV.
PART NUMBER TB600-45; LITTLE FUSE TYPE 251.250 OR
BUSSMAN TYPE MCR1/4. FOR NON UL APPLICATIONS,
A 10 OHM, 1/8W CARBON FILM RESISTOR MAY BE USED.
PART NUMBER 2643666611 OR 2943666661.
INTERRUPT
J1
TO AD1843
1
2
3
4
5
6
INDUCTOR
INDUCTOR
TO HOST
Figure 30. AD1843 Crystal Connections
C6, 1nF
L1
L2
XCTL0
RING
1.5kV
COIL
COIL
20–64pF
220
TIP (GREEN)
C5, 1nF
1.5kV
LO
LO
XTALI
HI
RING (RED)
18
23
22
15
29
14
17
8
7
2
RJ-11 JACK
24.576 MHz
TXA
TXA/
MONSUM
TIP
RING
OH/
RLY2/
AG0
AG1
POWER/
J1
SSI 73M9001
6
5
4
3
2
1
REOUT1
REOUT2
TRAN1
TRAN2
AGND
DGND
VCCA
VCCD
XTALO
SPK/
RXA
SPK
RI/
20–64pF
21
12
11
1
30
19
9
13
16
10
20
6
LOUT2LN
LOUT2LP
+5VA
220µF
AD1843
V
CC
TO
AD1843 LINLP
FROM AD1843
TO
AD1843 MIN
V
CC
56k