AD9252 Analog Devices, AD9252 Datasheet - Page 33

• Manufacturer Part Number: AD9252
• Description: Octal, 14-Bit, 50 MSPS, Serial LVDS, 1.8 V ADC
• Manufacturer: Analog Devices

Specifications of AD9252

• Resolution (bits): 14bit
• # Chan: 8
• Sample Rate: 50MSPS
• Interface: LVDS,Ser
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p,2 V p-p
• Adc Architecture: Pipelined
• Pkg Type: CSP

Data Sheet
EVALUATION BOARD
The AD9252 evaluation board provides all the support cir-
cuitry required to operate the ADC in its various modes and
configurations. The converter can be driven differentially by using
a transformer (default) or an
driven in a single-ended fashion. Separate power pins are provided
to isolate the DUT from the drive circuitry of the AD8334. Each
input configuration can be selected by changing the connections
of various jumpers (see Figure 62 to Figure 66). Figure 58 shows
the typical bench characterization setup used to evaluate the
ac performance of the AD9252. It is critical that the signal sources
used for the analog input and clock have very low phase noise
(<1 ps rms jitter) to realize the optimum performance of the
converter. Proper filtering of the analog input signal to remove
harmonics and lower the integrated or broadband noise at the
input is also necessary to achieve the specified noise performance.
See Figure 62 to Figure 72 for the complete schematics and
layout diagrams demonstrating the routing and grounding
techniques that should be applied at the system level.
POWER SUPPLIES
This evaluation board has a wall-mountable switching power
supply that provides a 6 V, 2 A maximum output. Connect the
supply to the rated 100 V ac to 240 V ac wall outlet at 47 Hz to
63 Hz. The other end of the supply is a 2.1 mm inner diameter
jack that connects to the PCB at P701. Once on the PC board,
the 6 V supply is fused and conditioned before connecting to
three low dropout linear regulators that supply the proper bias
to each of the various sections on the board.
When operating the evaluation board in a nondefault condition,
L701 to L704 can be removed to disconnect the switching
power supply. This enables the user to bias each section of the
WALL OUTLET
100V AC TO 240V AC
47Hz TO 63Hz
ROHDE & SCHWARZ,
ROHDE & SCHWARZ,
2V p-p SIGNAL
2V p-p SIGNAL
SYNTHESIZER
SYNTHESIZER
SMA,
SMA,
SWITCHING
POWER
SUPPLY
BAND-PASS
FILTER
2A MAX
6V DC
AD8334
XFMR
INPUT
CLK
driver. The ADC can also be
–
5.0V
+
EVALUATION BOARD
–
1.8V
AD9252
+
Figure 58. Evaluation Board Connection
–
1.8V
+
Rev. E | Page 33 of 52
CH A TO CH H
–
3.3V
SERIAL
14-BIT
LVDS
+
SPI
board individually. Use P702 to connect a different supply for
each section. At least one 1.8 V supply is needed for AVDD_DUT
and DRVDD_DUT; however, it is recommended that separate
supplies be used for both analog and digital signals and that each
supply have a current capability of 1 A. To operate the evaluation
board using the VGA option, a separate 5.0 V analog supply
(AVDD_5 V) is needed. To operate the evaluation board using
the SPI and alternate clock options, a separate 3.3 V analog supply
(AVDD_3.3 V) is needed in addition to the other supplies.
INPUT SIGNALS
When connecting the clock and analog sources to the
evaluation board, use clean signal generators with low phase
noise, such as Rohde & Schwarz SMA or HP8644 signal generators
or the equivalent, as well as a 1 m, shielded, RG-58, 50 Ω coaxial
cable. Enter the desired frequency and amplitude from the ADC
specifications tables. Typically, most Analog Devices, Inc., evalu-
ation boards can accept approximately 2.8 V p-p or 13 dBm
sine wave input for the clock. When connecting the analog
input source, it is recommended to use a multipole, narrow-band,
band-pass filter with 50 Ω terminations. Good choices of such
band-pass filters are available from TTE, Allen Avionics, and
K&L Microwave, Inc. The filter should be connected directly to
the evaluation board if possible.
OUTPUT SIGNALS
The default setup uses the Analog Devices HSC-ADC-FIFO5-
INTZ to interface with the Analog Devices standard dual-channel
FIFO data capture board (HCS-ADC-EVALCZ). Two of the
eight channels can be evaluated at the same time. For more
information on the channel settings and optional settings of
these boards, visit www.analog.com/FIFO.
INTERPOSER
BOARD
SPI
HSC-ADC-EVALCZ
FIFO DATA
CAPTURE
BOARD
–
3.3V
CONNECTION
SPI
+
USB
SPI
SOFTWARE
ANALYZER
RUNNING
AND SPI
USER
AD9252
ADC
PC