Evaluation Board Operation - Analog Devices AD9776A Manual

EVALUATION BOARD OPERATION

The AD9776A/AD9778A/AD9779A evaluation board is
designed to optimize the DAC performance and the speed of
the digital interface, yet remains user friendly. To operate the
board, the user needs a power source, a clock source, and a
digital data source. The user also needs a spectrum analyzer
or an oscilloscope to look at the DAC output. The diagram in
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CLOCK
GENERATOR
ADAPTER
CABLES
CLKIN
DIGITAL
PATTERN
GENERATOR
EVALUATION
CLOCK IN
DATACLK OUT
Figure 101. Typical Test Setup
AUX33
DVDD18
P4 DIGITAL INPUT CONNECTOR
AD9779A
S7 DCLKOUT
Figure 102. AD9776A/AD9778A/AD9779A Evaluation Board Showing All Connections
Rev. A | Page 49 of 60
AD9776A/AD9778A/AD9779A
Figure 101 illustrates the test setup. A sine or square wave clock
works well as a clock source. The dc offset on the clock is not a
problem, because the clock is ac-coupled on the evaluation board
before the REFCLK inputs. All necessary connections to the
evaluation board are shown in more detail in Figure 102.
SPI PORT
SPECTRUM
AD9776A/
ANALYZER
AD9778A/
AD9779A
BOARD
1.8V POWER SUPPLY
3.3V POWER SUPPLY
DVDD33 CVDD18 AVDD33
J2
5V SUPPLY
MODULATOR
J1 CLOCK IN
OUTPUT
JP4
S5 OUTPUT 1
JP15
JP8
JP14
ADL537x
JP3
JP16
JP2
S6 OUTPUT 2
JP17
LOCAL OSC
INPUT
ANALOG
DEVICES
AD9776A/
AD9788A/
SPI PORT
AD9779A
+5V
GND