UG-322: Evaluation Board for the AD5110 Digital Potentiometer PDF

Evaluation Board User Guide
UG-322
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
Evaluation Board for the AD5110 Digital Potentiometer
FEATURES
GENERAL DESCRIPTION
Full-featured evaluation board for the AD5110
Several test circuits
Various ac/dc input signals
PC control via a separately purchased system demonstration
platform (SDP)
PC control software
Resistor tolerance error stored in EEMEM
This user guide describes the evaluation board for evaluating the
AD5110—a single-channel, 128-position, nonvolatile memory
digital potentiometer.
The AD5110 supports single-supply 2.3 V to 5.5 V operation,
making the device suited for battery-powered applications and
many other applications, offering guaranteed low resistor
tolerance errors of ±8% and high bandwidth while allowing
up to ±6 mA current density in the A, B, and W pins.
PACKAGE CONTENTS
The logic voltage levels operate from single 1.8 V to 5.5 V
supplies.
EVAL-AD511xSDZ evaluation board
CD that includes
Self-installing software that allows users to control the
board and exercise all functions of the device
Electronic version of the AD5110 data sheet
Electronic version of the UG-322 user guide
The versatile I2C-compatible digital interface allows readback
of the wiper register and EEPROM content which contain the
resistor tolerance, providing an end-to-end tolerance accuracy
of 0.1%.
The EVAL-AD5110SDZ can operate in single-supply mode and
incorporates an internal power supply from the USB.
Complete specifications for the AD5110 part can be found in
the AD5110 data sheet, which is available from Analog Devices,
Inc., and should be consulted in conjunction with this user
guide when using the evaluation board.
10199-001
DIGITAL PICTURE OF EVALUATION BOARD WITH SYSTEM DEMONSTRATION PLATFORM
Figure 1.
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
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Evaluation Board User Guide
TABLE OF CONTENTS
Features .............................................................................................. 1
Test Circuits ...................................................................................4
Package Contents .............................................................................. 1
Evaluation Board Software ...............................................................5
General Description ......................................................................... 1
Installing the Software ..................................................................5
Digital Picture of Evaluation Board with System
Demonstration Platform.................................................................. 1
Running the Software ...................................................................5
Revision History ............................................................................... 2
Evaluation Board Schematics and Artwork ...................................7
Evaluation Board Hardware ............................................................ 3
Ordering Information .................................................................... 11
Power Supplies .............................................................................. 3
Bill of Materials ........................................................................... 11
Software Operation .......................................................................6
Link Options ................................................................................. 3
REVISION HISTORY
11/11—Revision 0: Initial Version
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Evaluation Board User Guide
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EVALUATION BOARD HARDWARE
POWER SUPPLIES
LINK OPTIONS
The EVAL-AD5110SDZ supports using single power supplies.
Several link and switch options are incorporated in the evaluation board and should be set up before using the board. Table 1
describes the positions of the links to control the evaluation board
by a PC, via the SDP board, using the EVAL-AD5110SDZ. The
functions of these link and switch options are described in
detail in Table 3.
The evaluation board can be powered either from the SDP
port or externally by the EXTERNAL-1 and EXTERNAL-2
connectors, as described in Table 2.
The digital logic levels can be powered either from the SDP
port or externally by the VLOGIC_EXT-1 and VLOGIC_EXT-2
connectors, as described in Table 2.
All supplies are decoupled to ground using 10 µF tantalum and
0.1 µF ceramic capacitors.
Table 1. Link Options Setup for SDP Control (Default)
Link No.
LK2
LK8
Option
3V3
+5V
Table 2. Maximum and Minimum Voltages of the Connectors
Connector Number
EXTERNAL-1
Label
VDD
EXTERNAL-2
VLOGIC_EXT-1
AGND
VLOGIC_EXT +
VLOGIC_EXT-2
VLOGIC_EXT −
Voltage
Analog positive power supply, VDD.
If connected to the SDP, VDD is 3.3 V to 5.5 V.
If controlled externally, VDD is 2.3 V to 5.5 V.
Analog ground, AGND.
Logic positive power supply, VLOGIC.
If connected to the SDP board, VLOGIC is 3.3 V.
If controlled externally, VLOGIC is 1.8 V to VDD.
Logic ground, DGND.
Table 3. Link Functions
Link Number
LK2
Power Supply
VLOGIC
LK8
VDD
1
Option
This link selects one of the following as the logic power supply:
3V3 (from SDP).
EXT (external supply from the VLOGIC_EXT connector).
This link selects one of the following as the positive power supply:
+5V (from SDP).
+3V3 (from SDP).
EXT 1 (external supply from the EXTERNAL connector).
If the part is powered using the external connector without connecting the SDP board, +5V jumper must be connected as well.
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Evaluation Board User Guide
AC Signal Attenuation
TEST CIRCUITS
The AD5110 can be used to attenuate an ac signal, which must
be provided externally using the AC_INPUT connector, as
shown in Figure 3.
The EVAL-AD5110SDZ incorporates several test circuits to
evaluate the AD5110 performance.
DAC
The AD5110 can be operated as a digital-to-analog converter
(DAC), as shown in Figure 2.
AC
HPF
AC
fC = 200Hz
A
–
W
W
BUF-W
12Ω
VOUT
+
A
A
–
A
750Ω
R9
12Ω
W
R7
B
VOUT
B
+
BUF-W
W
R8
B
B
VDD
2
R8
AC
GND
AC
Figure 3. AC Signal Attenuator
10199-002
VDD
2
750Ω
R9
DC
VDD
10199-003
VDD
2
VDD
2
AC_INPUT
GND
Table 4 shows the options available for the voltage references.
Depending on the voltage supply rails and the dc offset voltage
of the ac signal, various configurations can be used as described
in Table 5.
Table 4. DAC Voltage References
Table 5. AC Signal Attenuation Link Options
Figure 2. DAC
Terminal
A
Link
LK1
W
BUF-W
B
LK6
Options
AC
DC
AC
GND
Description
Connects Terminal A to VDD/2
Connects Terminal A to VDD
Connects Terminal W to an
output buffer
Connects Terminal B to VDD/2
Connects Terminal B to
analog ground
RDAC
256
Link
LK1
W
BUF-W
B
LK6
1
The output voltage is defined in Equation 1.
VOUT = (VA − VB ) ×
Terminal
A
Options
AC
AC1
GND
Description
Remove dc voltage and biased
the signal to VDD/2
Connects Terminal W to an
output buffer
Connects Terminal B to VDD/2
Connects Terminal B to analog
ground
Recommended to ensure optimal total harmonic distortion (THD) performance.
The signal attenuation is defined in Equation 2.
(1)
where:
RDAC is the code loaded in the RDAC register.
VA is the voltage applied to Terminal A (LK1 link).
VB is the voltage applied to Terminal B (LK6 link).
RDAC 
Attenuation (dB) ≈ 20 × log 

 128 
(2)
where:
RDAC is the code loaded in the RDAC register.
However, by using the R8 and R9 external resistors, the user can
reduce the voltage of the voltage references. In this case, use the
A and B test points to measure the voltage applied to the A and
B terminals and recalculate VA and VB in Equation 1.
In addition, R7 can be used to achieve an exponential attenuation. To do so, adjust the R7 resistor until a desirable transfer
function is found, typically around 1.6 kΩ for a 10 kΩ
potentiometer.
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EVALUATION BOARD SOFTWARE
INSTALLING THE SOFTWARE
RUNNING THE SOFTWARE
The EVAL-AD5110SDZ evaluation kit includes evaluation
board software provided on a CD. The software is compatible
with Windows® XP, Windows Vista, and Windows 7 (both 32
and 64 bits).
To run the evaluation board software, use the following steps:
1.
2.
Install the software before connecting the SDP board to the USB
port of the PC to ensure that the SDP board is recognized when
it is connected to the PC.
1.
2.
3.
4.
5.
Start the Windows operating system and insert the CD.
The installation software opens automatically. If it does
not, run the setup.exe file from the CD.
After the installation is completed, power up the evaluation
board as described in the Power Supplies section.
Plug the EVAL-AD511xSDZ into the SDP board and the SDP
board into the PC using the USB cable included in the box.
When the software detects the evaluation board, follow the
instructions that appear to finalize the installation.
Click Start > All Programs > Analog Devices > AD5110
> AD5110 Eval Board.
If the SDP board is not connected to the USB port when
the software is launched, a connectivity error is displayed
(see Figure 4). Connect the evaluation board to the USB
port of the PC, wait a few seconds, click Rescan, and follow
the instructions.
10199-004
To uninstall the program, click Start > Control Panel > Add or
Remove Programs > AD5110 Eval Board.
Figure 4. Pop-Up Window Error
10199-005
The main window of the EVAL-AD5110SDZ evaluation
software then opens, as shown in Figure 5.
Figure 5. EVAL-AD5110SDZ Evaluation Board Software Main Window
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OPERATING THE SOFTWARE
The main window of the EVAL-AD5110SDZ software is divided
into the following sections: QUICK COMMANDS, MANUAL
DATA, RDAC, and MEMORY. The features of the main
window are as follows:
•
•
The QUICK COMMANDS section allows you to send
quick commands directly to the AD5110.
The RDAC section can be used to update the RDAC
registers by typing a value into a text box and clicking
WRITE. When WRITE is clicked or a quick command
is executed, a write-read operation is performed and the
•
•
•
Rev. 0 | Page 6 of 12
values displayed in this section are updated with the actual
RDAC register values.
The MANUAL DATA can be used to send a customized
I2C data word by manually switching the scroll bars from 0
to 1 or from 1 to 0, as desired, and then clicking SEND
DATA. The scroll bars are updated upon each write
transfer.
The MEMORY section displays the data stored in the
memory block. The data can be updated manually by
clicking UPDATE.
Clicking EXIT closes the program but does not reset the part.
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10199-006
EVALUATION BOARD SCHEMATICS AND ARTWORK
Figure 6. Schematic of the AD5110 Circuitry
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10199-007
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Figure 7. Schematic of SDP Connector
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10199-008
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10199-009
Figure 8. Component Placement Drawing
Figure 9. Component Side PCB Drawing
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10199-010
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Figure 10. Solder Side PCB Drawing
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ORDERING INFORMATION
BILL OF MATERIALS
Table 6.
Qty
1
2
4
2
1
2
1
8
1
1
1
1
4
2
2
7
1
1
1
1
1
1
Reference Designator
C3
C1,C2
C25, C26, C27, C34
C24, C33
D1
VLOGIC_EXT, EXTERNAL
J4
LK1, LK2, LK3, LK4, LK5, LK6, LK8, ASE
BUF-W
R11
R10
R4
R5, R6, R12, R13
R8, R9
DGND, AGND
3V3, A, B, VDD, VLOGIC, VOUT, W
U1
U3
U5
U7
U15
Description
100 nF, 0402 capacitor
0.1 µF, 0603 capacitor
0.1 µF, 0603 capacitor
10 µF, 1206 capacitor
Green LED
2-pin connector
Receptacle, 0.6 mm, 120 way
Header, 2-row, 36 + 36 way, and jumper socket, black
Supplier 1/Part Number
FEC 1414580
FEC 138-2224
FEC 301-9482
FEC 197-130
FEC 579-0852
FEC 151789
Digi-Key H1219-ND
FEC 148-535 and FEC 150-411
Header, 1-row, 2-way, and jumper socket, black
12 Ω, 0603, 1% resistor
750 Ω, 0603, 1% resistor
1 kΩ, 0603, 0.01% resistor
2.7 kΩ, 1206, 1% resistor
0 Ω, 0603 resistor
Test point, PCB, black, PK100
Test point, PCB, red, PK100
AD5110
ADA4860
ADP3303
24LC64 serial EEPROM
AD8652
FEC 102-2247 and FEC 150-411
FEC 9330534
FEC 9331506
FEC 9330380
FEC 9337288
FEC 9331662
FEC 873-1128
FEC 873-1144
Analog Devices AD5110
Analog Devices ADA4860
Analog Devices ADP3303
FEC 9758070
Analog Devices AD8652
FEC refers to Farnell Electronic Component Distributors.
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Evaluation Board User Guide
NOTES
I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors).
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.
©2011 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
UG10199-0-11/11(0)
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