AD9835EB Datasheet, PDF (1/8 Pages) Analog Devices – Evaluation Board for the AD9835 Direct Digital Synthesizer

a
Evaluation Board for the AD9835
Direct Digital Synthesizer
EVAL-AD9835EB
FEATURES
Full-Featured Evaluation Board for the AD9835
Various Linking Options
PC Software for Control of AD9835
On-Board Patchwork Area
INTRODUCTION
This Application Note describes the evaluation board for
the AD9835 Direct Digital Synthesizer (DDS). The
AD9835 is a numerically controlled oscillator employing
a phase accumulator, a sine look-up table and a 10-bit D/
A converter. The part can be operated with clock
frequencies up to 50 MHz. Both phase modulation and
frequency modulation can be performed with the AD9835.
Full data on the AD9835 is available in the AD9835
datasheet available from Analog Devices and should be
consulted in conjunction with this Application Note when
using the evaluation board.
The evaluation board interfaces to the parallel port of an
IBM compatible PC. Software is available with the
evaluation board which allows the user to easily program
the AD9835.
Components on the AD9835 Evaluation Board include a
50 MHz oscillator which provides the MCLK for the
AD9835. The user can remove this oscillator, if required,
and drive the AD9835 with a different clock oscillator or
an external clock source via a BNC connector. A digital
buffer is also on the board so that the signals from the
edge connector are buffered.
OPERATING THE AD9835 EVALUATION BOARD
Power Supplies
This evaluation board has two analog power supply inputs:
AV_DD and AGND. AV_DD equals +5V or +3.3V and is used
to provide the AV_DD for the AD9835. DGND and DV_DD
connections are also available. The DV_DD is used to
provide the DV_DD for the AD9835, the 50 MHz oscillator
and the DV_DD for the digital buffer. DGND and AGND
are connected under the AD9835. Therefore, it is
recommended not to connect AGND and DGND
elsewhere in the system.
All power supplies are decoupled to ground. AV_DD and
DV_DD are decoupled using 10µF tantalum capacitors and
0.1µF ceramic capacitors at the input to the evaluation
board. The power supplies are again decoupled using
0.1µF capacitors at the AD9835, the crystal and the logic.
AD 98 35 .E XE
Figure 1: Evaluation Board Setup
IBM Com patible PC
Parallel Port Centronics
Printer C able
AD 9835
Evaluation Board
Information furnished by Analog Devices is believed to be accurate
and reliable. However, no responsibility is assumed by Analog Devices
for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices.
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