Evaluation Board User Guide
UG-333
One
Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com
Evaluating the
AD5445
Parallel Input, Current Output DAC
FEATURES
Full-featured evaluation board for the AD5445
Graphic user interface software for board control and data analysis
Connector to EVAL-SDP-CB1Z system demonstration platform board
Various power supply options
APPLICATIONS
Portable battery-powered applications
Waveform generators
Analog processing
Instrumentation applications
Programmable amplifiers and attenuators
Digitally controlled calibration
Programmable filters and oscillators
Composite video
Ultrasound
Gain, offset, and voltage trimming
GENERAL DESCRIPTION
The AD5445
1
is a CMOS, 12-bit, current output digital-to-analog
converter (DAC). This device operates from a 2.5 V to 5.5 V power supply, making it suitable for battery-powered applications and many other applications. For evaluation purposes, however, the voltage is limited to 3.3 V due to EVAL-SDP-CB1Z restrictions.
This DAC utilizes data readback, allowing the user to read the contents of the DAC register via the DB pins. Upon power-up, the internal register and latches are filled with 0s, and the DAC outputs are at zero scale.
As a result of manufacturing with a CMOS submicron process, this part offers excellent four-quadrant multiplication characteristics, with large-signal multiplying bandwidths of up to 10 MHz.
The applied external reference input voltage (V
REF
) determines the full-scale output current. An integrated feedback resistor (R
FB
) provides temperature tracking and full-scale voltage output when combined with an external current-to-voltage precision amplifier.
Although compared with the AD7545 , the AD5445 is an upgrade in terms of the multiplying bandwidth performance, the AD5445 has a latched interface and cannot be used in transparent mode.
The AD5445 DAC is available in small, 20-lead LFCSP and
TSSOP packages.
The evaluation board, EVAL-AD5445SDZ , is available for evaluating the performance of the AD5445 DAC.
EVALUATION BOARD FUNCTIONAL BLOCK DIAGRAM
V
DD
V
REF
AD5445
12-BIT
R-2R DAC
R
R
FB
I
OUT
1
I
OUT
2
POWER-ON
RESET
DAC REGISTER
CS
R/W
INPUT LATCH
GND
DB0 DB11
DATA
INPUTS
Figure 1.
1 U.S Patent No. 5,689,257.
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
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TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
General Description ......................................................................... 1
Evaluation Board Functional Block Diagram ............................... 1
Revision History ............................................................................... 2
Evaluation Board .............................................................................. 3
System Demonstration Platform ................................................ 3
Operating the Evaluation Board ................................................. 3
Microprocessor Interfacing ......................................................... 3
REVISION HISTORY
8/12—Revision 0: Initial Version
Evaluation Board User Guide
Evaluation Board Software ...............................................................4
Installing the Software ..................................................................4
Running the Software ...................................................................4
Using the Evaluation Board Software .............................................5
Evaluation Board Functions and Registers ....................................5
Evaluation Board Schematics and Artwork ...................................6
Schematics ......................................................................................6
Evaluation Board Layout ..............................................................8
Related Links ..................................................................................9
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Evaluation Board User Guide
EVALUATION BOARD
The EVAL-AD5445SDZ evaluation board consists of an AD5445
DAC and a current-to-voltage amplifier, the AD8065 . Included on the evaluation board is a 10 V reference, the ADR01 . An external reference can also be applied via an SMB input. The evaluation kit includes a CD-ROM with self-installing PC-based software to control the DAC. The software allows the user to write a code to the device and to read a code from the device.
The EVAL-AD5445SDZ evaluation board is used in conjunction with the EVAL-SDP-CB1Z board, which is available from Analog
Devices, Inc., and must be purchased separately from the evaluation board. The USB-to-SPI communication to the AD5445 is completed using this Blackfin®-based demonstration board. The software offers a waveform generator.
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
ADSP-BF527 processor with USB connectivity to the PC through a USB 2.0 high speed port. For more information about this device, see the SDP-B Web page.
OPERATING THE EVALUATION BOARD
The board requires ±12 V and +5 V supplies. The +12 V V
DD
and
−12 V V
SS
supplies are used to power the output amplifier; the +5 V supply is used to power the DAC (V
DD1
) and transceivers (V
CC
).
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Both supplies are decoupled to their respective ground plane using 10 µF tantalum and 0.1 µF ceramic capacitors.
MICROPROCESSOR INTERFACING
The SDP is a hardware and software platform that provides a means to communicate from the PC to Analog Devices products and systems that require digital control and/or readback. The
SDP has a Blackfin processor ( ADSP-BF5xx ) at its core.
The ADSP-BF5xx processor incorporates an asynchronous parallel port. An asynchronous parallel interface between the
Blackfin processor and the AD5445
DAC is shown in Figure 2.
For more information about the system demonstration platform, see the SDP-B Web page.
PAR_D1
PAR_D2
DB1
DB2
PAR_D10
PAR_D11
DB10
DB11
PAR_CS
PAR_WR
CS
R/W
SDP STANDARD CONNECTOR
FOR BLACKFIN
®
ADSP-BF5xx
EVAL-AD5445SDZ
Figure 2. ADSP-BF5xx -toAD5445 Interface
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EVALUATION BOARD SOFTWARE
INSTALLING THE SOFTWARE
The EVAL-AD5445SDZ evaluation kit includes a CD containing the software and drivers. To install the software, follow these steps:
1.
Install the software before connecting the SDP board to the
USB port of the PC.
2.
Start the Windows® operating system, and insert the CD included in the EVAL-AD5445SDZ evaluation board kit.
3.
Download the EVAL-AD5445SDZ LabVIEW® software. The correct driver, SDPDriversNET, for the SDP board should download automatically after LabVIEW is downloaded, supporting both 32- and 64-bit systems. However, if the driver does not download automatically, the driver executable file can also be found in the
Analog Devices
folder (from the
Start
menu, point to
All Programs
and then click
Analog
Devices
). Follow the on-screen prompts to install the driver.
4.
After installation of the software and drivers is complete, plug the EVAL-AD5445SDZ into the SDP board and plug the SDP board into the PC using the USB cable included in the evaluation board kit.
5.
When the software detects the evaluation board, proceed through any dialog boxes that appear to finalize the installation (such as
Found New Hardware Wizard/Install the Software Automatically
).
Evaluation Board User Guide
RUNNING THE SOFTWARE
To run the evaluation board program,
1.
From the
Start
menu, point to
All Programs
and then click
Analog Devices
and
EVAL-AD5445SDZ
.
2.
If the SDP board is not connected to the USB port when the software is launched, a connectivity error displays (see
Figure 3.). If this message appears, connect the evaluation
board to the USB port of the PC, wait a few seconds, click
Rescan
, and follow the on-screen instructions.
Figure 3. Connectivity Error
Figure 4. Device Manager Showing the SDP Board Connected
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Evaluation Board User Guide
USING THE EVALUATION BOARD SOFTWARE
To operate the evaluation board software,
1.
Ensure that the USB cable connects the PC to the system demonstration platform (SDP1Z) and the SDPIZ to the evaluation board.
2.
Run the program file from the
Analog Devices
menu. The
EVAL-AD5445SDZ
window is displayed, as shown in
Figure 5.
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EVALUATION BOARD FUNCTIONS AND REGISTERS
The AD5445 evaluation software window allows you to write a data-word to or to read a data-word from the DAC.
Example 1
Type 0x800 (the 12-bit midscale data value) in the
Input Data
box, and click
Write DAC
. The output should then show a voltage of
−5 V, based on the following formula:
V
OUT
= −
V
REF
×
2
D n
Example 2
= −
10
×
2048
4096
= −
5 V
Type 0xBFD (the three quarter scale data value) in the
Input
Data
box, and then click
Write DAC
. The output should then show a voltage of −7.5 V, based on the following formula:
V
OUT
= −
V
REF
×
2
D n
= −
10
×
3069
4096
= −
7 .
5 V
Click
Read DAC
. The
Output Data
indicator should then show the 12-bit data value of the last data written to the part. Therefore, for this example, the indicator would show a value of 0xBFD.
Figure 5. Evaluation Software Window
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EVALUATION BOARD SCHEMATICS AND ARTWORK
SCHEMATICS
Evaluation Board User Guide
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Figure 6. Evaluation Board Schematic, SDP Board ( EVAL-SDP-CB1Z )
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Evaluation Board User Guide
+
+
C6
C5
µF 0.1
10µF
DB
DB
6
7
8 DB
9 DB
4
3
5 DB
DB
DB
10 DB
11 DB
S /C
0 DB
1 DB
2 DB
R/W
Figure 7. Evaluation Board Schematic, AD5445
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EVALUATION BOARD LAYOUT
Figure 8. Silkscreen
Figure 9. Component Side
Figure 10. Solder Side
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Evaluation Board User Guide
Evaluation Board User Guide
RELATED LINKS
Resource Description
AD5445
EVAL-SDP-CB1Z
AD7545
AD8065
ADR01
ADSP-BF527
Product Page—12-Bit, High Bandwidth Multiplying DAC with Parallel Interface
Product Page—SDP-B: System Demonstration Platform-Blackfin
Product Page—CMOS 12-Bit Buffered Multiplying DAC with On-Board Data Latches
Product Page—High Performance, 145 MHz
FastFET
™ Op Amp
Product Page—Ultracompact, Precision 10.0 V Voltage Reference
Product Page—Low Power Blackfin Processor with Advanced Peripherals
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NOTES
Evaluation Board User Guide
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NOTES
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NOTES
Evaluation Board User Guide
ESD Caution
ESD (electrostatic discharge) sensitive device
. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.
Legal Terms and Conditions
By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc.
(“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term
“Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board.
Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO
WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED
TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL
PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF
THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE
AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable
United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of
Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby submits to the personal jurisdiction and venue of such courts. The United Nations Convention on Contracts for the International Sale of Goods shall not apply to this Agreement and is expressly disclaimed.
©2012 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.
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