AD9467 Analog Devices, AD9467 Datasheet - Page 20

• Manufacturer Part Number: AD9467
• Description: 16-Bit, 200 MSPS/250 MSPS Analog-to-Digital Converter
• Manufacturer: Analog Devices

Specifications of AD9467

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 250MSPS
• Interface: LVDS,Par
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: (2Vref) p-p,2 V p-p,2.5V p-p
• Adc Architecture: Pipelined,Subranging
• Pkg Type: CSP

AD9467
AD9467BCPZ-200 buffer current settings:
•
•
•
Note that for sample rates less than 150 MSPS and analog inputs
less than 100 MHz, it is recommended to set the buffer current
to 0%. Depending on the input network design and frequency
band of interest, the optimum buffer current settings may be
slightly different than the input network recommendations shown
in Figure 53 and Figure 54.
DC to 150 MHz at 80% (default setting)
150 MHz to 250 MHz at 100%
250 MHz and higher at 160%
100
98
96
94
92
90
88
86
84
82
80
0
Figure 50. Buffer Current Sweeps, 2.5 V p-p, AD9467-200
50
ANALOG INPUT FREQUENCY (MHz)
100
Figure 52. Differential Transformer-Coupled Configuration for IF Applications from 150 MHz to 300 MHz
Figure 51. Differential Transformer-Coupled Configuration for Baseband Applications up to 150 MHz
SMA
SMA
Figure 53. Wideband Balun-Coupled Configuration for IF Applications Up Greater Than 100 MHz
ANALOG
150
10nH 0.1µF
10nH 0.1µF
IN
Z = 50Ω
Z = 50Ω
INPUT
INPUT
200
B0205F5050A00
80%
100%
160%
1
2
3
ANAREN
ADT1-1WT
ADT1-1WT
0.1µF
0.1µF
4 5
250
8
7
6
0.1µF
0.1µF
ADT1-1WT
ADT1-1WT
300
0.1μF
0.1μF
C1
C2
Rev. C | Page 20 of 32
33Ω
33Ω
0.1µF
0.1µF
R1
R2
0.1µF
0.1µF
0.1µF
0.1µF
33Ω
33Ω
33Ω
33Ω
0.1μF
C3
15Ω
15Ω
R5
R6
VCM
0.1µF
0.1µF
Differential Input Configurations
There are several ways to drive the AD9467, either actively or
passively; however, optimum performance is achieved by
driving the analog input differentially.
For applications where SNR and SFDR are key parameters,
differential transformer coupling is the recommended input
configuration (see Figure 51 and Figure 52) because the noise
performance of most amplifiers is not adequate to achieve the
true performance of the AD9467.
Regardless of the configuration, the value of the shunt capacitor,
C, is dependent on the input frequency and may need to be
reduced or removed (see Figure 51, Figure 52, and Figure 53)
Using the
AD9467 provides an excellent and flexible gain option to interface
to the ADC (see Figure 54 and Figure 56) for both baseband and
high IF applications. Using an amplifier also provides better
isolation from the preceding stages as well as better pass-band
flatness. Performance plots of these amplifiers can also be seen
in Figure 55 and Figure 57.
When using any dc-coupled amplifier, the user has the option
to disconnect the input common-mode voltage buffer from the
analog inputs. This allows the common-mode output pin of the
amplifier to set this voltage between the interface of the two
devices. Otherwise, use an ac coupling capacitor in series on
each of the analog input as shown in Figure 54 for IF applica-
tions that do not require dc coupling. See the Memory Map
section for more details.
50Ω
50Ω
R3
R4
4.7pF
1.8pF
33Ω
33Ω
15Ω
15Ω
24Ω
24Ω
20Ω
20Ω
8.2pF
8.2pF
C6
C5
15Ω
15Ω
R7
R8
ADL5562
AIN+
AIN–
AIN+
AIN–
530Ω
530Ω
AIN+
AIN–
or
AD9467
3.5pF
3.5pF
ADL5201
INTERNAL
INTERNAL
AD9467
AD9467
INPUT Z
INPUT Z
ADC
ADC
differential drivers to drive the
Data Sheet