Analog Devices AD9284-250EBZ, User Manual

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AD9284-250EBZ User Guide UG-178
Rev. A | Page 3 of 24
EVALUATION BOARD HARDWARE
The AD9284 evaluation board provides all of the support
circuitry required to operate the AD9284 in its various modes
and configurations. Figure 2 shows the typical bench charac-
terization setup used to evaluate the ac performance of the
AD9284 . 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 signal chain. Proper
filtering of the analog input signal to remove harmonics and
lower the integrated or broadband noise at the input is necessary
to achieve the specified noise performance.
See the Evaluation Board Software Quick Start Procedures
section to get started, and see Figure 13 to Figure 25 for the
complete schematics and layout diagrams. These diagrams
demonstrate the routing and grounding techniques that
should be applied at the system level when designing
application boards using the
AD9284 .
POWER SUPPLIES
This evaluation board comes with 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 the 240 V ac wall outlet at
47 Hz to 63 Hz. The output from the supply is provided through
a 2.1 mm inner diameter jack that connects to the printed circuit
board (PCB) at J101. The 6 V supply is fused and conditioned
on the PCB before connecting to the low dropout linear regulators
(default configuration) that supply the proper bias to each of the
various sections on the board.
INPUT SIGNALS
When connecting the clock and analog source, use clean signal
generators with low phase noise, such as the Rohde & Schwarz SMA,
or HP8644B signal generators or an equivalent. Use a 1 m shielded,
RG-58, 50 Ω coaxial cable for connecting to the evaluation
board. Enter the desired frequency and amplitude (see the
specifications in the
AD9284 data sheet). When connecting the
analog input source, a multipole, narrow-band, band-pass filter
with 50 Ω terminations is recommended. Analog Devices, Inc.,
uses TTE and K&L Microwave, Inc., band-pass filters. The
filters should be connected directly to the evaluation board.
If an external clock source is used, it should also be supplied
with a clean signal generator as previously specified. Typically,
most Analog Devices evaluation boards can accept ~2.8 V p-p or
13 dBm sine wave input for the clock.
OUTPUT SIGNALS
The default setup uses the Analog Devices high speed converter
evaluation platform (HSC-ADC-EVALCZ) for data capture.
6V DC
2A MAX
6V DC
2A MAX
SWITCHING
POWER
SUPPLY
SWITCHING
POWER
SUPPLY
WALL OUTLET
100V TO 240V AC
47Hz TO 63Hz
PC RUNNING
VisualAnalog
AND SPIController
USER SOFTWARE
SIGNAL GENERATOR
CLOCK SOURCE
SIGNAL GENERATOR
ANALOG FILTER
SIGNAL GENERATOR
ANALOG FILTER
09228 -
002
9284EE01
REV A
AD9284
9284EE02A
HSC-ADC-EVALCZ
Figure 2. Evaluation Board Connection