UG-207 Datasheet, PDF (3/16 Pages) Analog Devices – Evaluation Board for 1 GSPS DDS with 14-Bit DAC

Evaluation Board User Guide
EVALUATION BOARD HARDWARE
REQUIREMENTS
To successfully use the evaluation board and run the software,
the requirements listed in Table 1 must be met.
Table 1. AD9910/PCBZ Requirements
Item
Requirement
Operating
System
Windows® 98/ME/2000/XP
Processor
Pentium® I or later
Memory
128 MB minimum
Ports
One USB port
Clocking
Signal generator capable of generating
sinusoidal waves of at least 0 dBm, up to at
least 10 MHz
Power Supplies Capability to generate at least two
independent dc voltages (1.8 V/3.3 V)
Measurement
Appropriate measurement device, such as a
spectrum analyzer or a high bandwidth
oscilloscope
Cables
USB 1.1/2.0 cable, and SMA-to-X cables (X =
SMA or BNC, depending on the connector of
the device interfacing with the board)
SETTING UP THE EVALUATION BOARD
DC Power Supply
The AD9910 evaluation board has two power supply connectors
(four pins each): TB1 and TB2. TB1 powers the USB interface
circuitry, the digital I/O interface, and the digital core. TB2
powers the DAC and the clock input circuitry.
CONNECTORS
Table 2 shows the necessary connections and the appropriate
biasing voltage.
Table 2. Connections and Biasing Voltage
Connector
Pin No. Label
TB1
1
VCC_USB
TB1
2
GND
TB1
3
DVDD_IO
TB1
4
DVDD
TB2
1, 3
GND
TB2
2
DAC_VDD
TB2
4
CLK_VDD
Voltage (V)
3.3
0
3.3
1.8
0
3.3
1.8
UG-207
Device Clock Oscillator Options
The AD9910 architecture provides the user with three options
when providing an input signal to the part. The first option allows
the user to provide a high frequency input signal, connected to J1.
The second option allows the user to connect using a lower input
reference frequency, enabling the clock multiplier, and connects
through J1. The third option allows the user to connect a crystal
resonator on the backside of the board.
Note that the AD9910 evaluation board does not populate the
PLL loop filter components. Therefore, to use the internal PLL of
the AD9910, the user must solder down these components, or
else the PLL is not stable. The AD9910 data sheet has helpful
formulas to calculate the appropriate values. In addition, an Excel
file to help choose the loop filter component values is available at
www.analog.com. Go to the AD9910 product page and click on
the Evaluation Boards and Development Kits tab.
To enable the crystal mode, switch the jumper, W7, to the XTAL
mode. Remove C51 and 52. Place 0 (zero) Ω resistors at R4 and
R11 on the backside of the board. The crystal oscillates at 25 MHz.
Refer to the AD9910 data sheet for details on the maximum input
speeds and input sensitivities of these two inputs.
Device Communication Requirements
Two interface options are available on the evaluation board.
• USB 1.1/2.0
• Header row (U5 and U9), which places the part under the
control of an external controller (such as a microprocessor,
FPGA, or DSP)
Analog Devices provides a GUI for the PC; it does not provide
control software for external controllers.
JUMPERS
Use the jumper settings listed in Table 3 to enable different
modes of communication.
Table 3. Jumper Settings for Communication Modes
Mode
Settings
PC Control,
USB Port
Set Jumper W1 and Jumper W2 to enable. Set
Jumper W4 to enable. Place a jumper on W5, W6,
and W3.
External
Control
Set Jumper W1and Jumper W2 to disable. Set
Jumper W4 to disable. Remove the jumper on
W5, W6, and W3.
Jumper W1, Jumper W2, and Jumper W4 enable the USB
circuitry to control the AD9910. Jumper W3 controls the
EEPROM, used in starting up the USB circuitry. Jumper W5
and Jumper W6 control Signal SDO and Signal SDIO to and
from the AD9910.
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