Datasheet

AD9835 Data Sheet
Rev. A | Page 22 of 28
EVALUATION BOARD
SYSTEM DEMONSTRATION PLATFORM
The system demonstration platform (SDP) is a hardware and
software evaluation tool for use in conjunction with product
evaluation boards. The SDP board is based on the Blackfin® BF527
processor with USB connectivity to the PC through a USB 2.0 high
speed port.
Note that the SDP board is sold separately from the AD9835
evaluation board.
AD9835 TO SPORT INTERFACE
The Analog Devices SDP board has a SPORT serial port that is
used to control the serial inputs to the AD9835. The connections
are shown in Figure 30.
AD9835
FSYNC
SDATA
SCLK
09630-039
SPORT_TFS
SPORT_TSCLK
SPORT_DTO
ADSP-BF527
Figure 30. SDP to AD9835 Interface
The AD9835 evaluation board allows designers to evaluate the
high performance AD9835 DDS modulator with a minimum of
effort. The GUI interface for the AD9835 evaluation board is
shown in Figure 31.
09630-035
Figure 31. AD9835 Evaluation Software
The DDS evaluation kit includes a populated, tested AD9835
PCB. Software is available with the evaluation board that allows
the user to easily program the AD9835. The schematics and
layout of the AD9835 evaluation board are shown in Figure 32
through Figure 36. The software runs on any IBM-compatible PC
that has Microsoft® Windows® 95, Windows 98, Windows ME,
Windows 2000 NT®, or Windows 7 installed.
Additional details can be found in the EVAL-AD9835SDZ data
sheet (UG-319) that is available on the software CD and on the
AD9835 product page.
XO vs. EXTERNAL CLOCK
The AD9835 can operate with master clocks up to 50 MHz. A
50 MHz general oscillator is included on the evaluation board.
However, this oscillator can be removed and, if required, an
external CMOS clock can be connected to the part.
Two options for the general oscillator are:
• AEL 301 series crystals oscillators (AEL Crystals, Ltd.)
• SG-310SCN oscillators (Epson Toyocom Corporation)
POWER SUPPLY
Power to the AD9835 evaluation board can be provided from a
USB connector or externally through pin connections. The
power leads should be twisted to reduce ground loops.