Datasheet

Data Sheet ADV7342/ADV7343
Rev. | Page 73 of 108
DAC
OUTPUT
390nH
33pF
33pF
75Ω
500Ω
300Ω
75Ω
BNC
OUTPUT
500Ω
3
4
1
3
4
1
06399-087
Figure 85. Example of Output Filter for HD, 4× Oversampling
0
–80
–70
–60
–50
–40
–30
–20
–10
0
–30
–60
–90
–120
–150
–180
–210
–240
1M 10M 100M
FREQUENCY (Hz)
CIRCUIT FREQUENCY RESPONSE
1G
GROUP DELAY (Seconds)
PHASE (Degrees)
MAGNITUDE (dB)
21n
18n
15n
12n
9n
6n
3n
0
24n
GAIN (dB)
06399-088
Figure 86. Output Filter Plot for SD, 16× Oversampling
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
1M 10M 100M 1G
FREQUENCY (Hz)
CIRCUIT FREQUENCY RESPONSE
MAGNITUDE (dB)
GROUP DELAY (Seconds)
PHASE
(Degrees)
GAIN (dB)
320
240
160
80
0
–80
–160
–240
480
400
14n
12n
10n
8n
6n
4n
2n
0
18n
16n
06399-089
Figure 87. Output Filter Plot for ED, 8× Oversampling
0
–50
1
FREQUENCY (MHz)
CIRCUIT FREQUENCY RESPONSE
GAIN (dB)
PHASE (Degrees)
10 100
–10
–20
–30
–40
200
–200
120
40
–40
–120
GROUP DELAY (Seconds)
PHASE
(Degrees)
MAGNITUDE (dB)
06399-090
Figure 88. Output Filter Plot for HD, 4× Oversampling
PRINTED CIRCUIT BOARD (PCB) LAYOUT
The ADV7342/ADV7343 are highly integrated circuits
containing both precision analog and high speed digital
circuitry. They are designed to minimize interference effects on
the integrity of the analog circuitry by the high speed digital
circuitry. It is imperative that these same design and layout
techniques be applied to the system-level design so that optimal
performance is achieved.
The layout should be optimized for lowest noise on the
ADV7342/ADV7343 power and ground planes by shielding the
digital inputs and providing good power supply decoupling.
It is recommended to use a 4-layer printed circuit board with
ground and power planes separating the signal trace layer and
the solder side layer.
Component Placement
Component placement should be carefully considered to
separate noisy circuits, such as clock signals and high speed
digital circuitry, from analog circuitry.
The external loop filter components and components connected
t o t he C O M P, V
REF
, and R
SETx
pins should be placed as close as
possible to and on the same side of the PCB as the ADV7342/
ADV7343. Adding vias to the PCB to get the components closer
to the ADV7342/ADV7343 is not recommended.
It is recommended that the ADV7342/ADV7343 be placed as
close as possible to the output connector, with the DAC output
traces as short as possible.
The termination resistors on the DAC output traces should be
placed as close as possible to and on the same side of the PCB as
the ADV7342/ADV7343. The termination resistors should
overlay the PCB ground plane.
D