Analog Devices EVAL-AD51150SDZ User manual

Evaluation Board User Guide
UG-322
One Technology Way •P. O . Box 9106 •Norwood, MA 02062-9106, U.S.A. •Tel: [phone] •Fax: [phone] •www.analog.com
Evaluation Board for the AD5110 Digital Potentiometer
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.Rev. 0 | Page 1 of 12
FEATURES
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
PACKAGE CONTENTS
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
GENERAL DESCRIPTION
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.
The logic voltage levels operate from single 1.8 V to 5.5 V
supplies.
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 E VA L-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.
DIGITAL PICTURE OF EVALUATION BOARD WITH SYSTEM DEMONSTRATION PLATFORM
10199-001
Figure 1.

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TABLE OF CONTENTS
Features .............................................................................................. 1
Package Contents .............................................................................. 1
General Description ......................................................................... 1
Digital Picture of Evaluation Board with System
Demonstration Platform.................................................................. 1
Revision History ............................................................................... 2
Evaluation Board Hardware ............................................................ 3
Power Supplies .............................................................................. 3
Link Options ................................................................................. 3
Test Circuits ...................................................................................4
Evaluation Board Software...............................................................5
Installing the Software ..................................................................5
Running the Software ...................................................................5
Software Operation .......................................................................6
Evaluation Board Schematics and Artwork...................................7
Ordering Information.................................................................... 11
Bill of Materials........................................................................... 11
REVISION HISTORY
11/11—Revision 0: Initial Version

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EVALUATION BOARD HARDWARE
POWER SUPPLIES
The E VA L -AD5110SDZ supports using single power supplies.
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.
LINK OPTIONS
Several link and switch options are incorporated in the evalu-
ation 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 E VA L -AD5110SDZ. The
functions of these link and switch options are described in
detail in Table 3.
Table 1. Link Options Setup for SDP Control (Default)
Link No. Option
LK2 3V3
LK8 +5V
Table 2. Maximum and Minimum Voltages of the Connectors
Connector Number Label Voltage
EXTERNAL-1 VDD 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.
EXTERNAL-2 AGND Analog ground, AGND.
VLOGIC_EXT-1 VLOGIC_EXT + 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.
VLOGIC_EXT-2 VLOGIC_EXT −Logic ground, DGND.
Table 3. Link Functions
Link Number Power Supply Option
LK2 VLOGIC This link selects one of the following as the logic power supply:
3V3 (from SDP).
EXT (external supply from the VLOGIC_EXT connector).
LK8 VDD This link selects one of the following as the positive power supply:
+5V (from SDP).
+3V3 (from SDP).
EXT1(external supply from the EXTERNAL connector).
1If the part is powered using the external connector without connecting the SDP board, +5V jumper must be connected as well.

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TEST CIRCUITS
The E VA L -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.
VOUT
V
DD
AC
DC
GND
A
BWBUF-W +
–
W
AC
V
DD
2
V
DD
2
B
A
750Ω
12Ω
R9
R8
10199-002
Figure 2. DAC
Table 4 shows the options available for the voltage references.
Table 4. DAC Voltage References
Terminal Link Options Description
A LK1 AC Connects Terminal A to VDD/2
DC Connects Terminal A to VDD
W BUF-W Connects Terminal W to an
output buffer
B LK6 AC Connects Terminal B to VDD/2
GND Connects Terminal B to
analog ground
The output voltage is defined in Equation 1.
256
)( RDAC VVV B
A
OUT ×−=
(1)
where:
RDAC is the code loaded in the RDAC register.
VAis the voltage applied to Ter minal A (LK1 link).
VBis the voltage applied to Terminal B (LK6 link).
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 VAand VBin Equation 1.
AC Signal Attenuation
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.
B
A
AC
AC
GND
A
BW
BUF-W
AC_INPUT
WVOUT
+
–
VDD
2
VDD
2
HPF
f
C= 200Hz
12Ω
750Ω
R8
R9
R7
10199-003
Figure 3. AC Signal Attenuator
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 5. AC Signal Attenuation Link Options
Terminal Link Options Description
A LK1 AC Remove dc voltage and biased
the signal to VDD/2
W BUF-W Connects Terminal W to an
output buffer
B LK6 AC1Connects Terminal B to VDD/2
GND Connects Terminal B to analog
ground
1Recommended to ensure optimal total harmonic distortion (THD) performance.
The signal attenuation is defined in Equation 2.






×≈ 128 log20)dB(RDAC nAttenuatio
(2)
where:
RDAC is the code loaded in the RDAC register.
In addition, R7 can be used to achieve an exponential attenua-
tion. 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
The E VA L -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).
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. Start the Windows operating system and insert the CD.
2. The installation software opens automatically. If it does
not, run the setup.exe file from the CD.
3. After the installation is completed, power up the evaluation
board as described in the Power Supplies section.
4. P lu g t he EVA L -AD511xSDZ into the SDP board and the SDP
board into the PC using the USB cable included in the box.
5. When the software detects the evaluation board, follow the
instructions that appear to finalize the installation.
To uninstall the program, click Start > Control Panel > Add or
Remove Programs > AD5110 Eval Board.
RUNNING THE SOFTWARE
To run the evaluation board software, use the following steps:
1. Click Start > All Programs > Analog Devices > AD5110
>AD5110 Eval Board.
2. 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
Figure 4. Pop-Up Window Error
The main window of the E VA L -AD5110SDZ evaluation
software then opens, as shown in Figure 5.
10199-005
Figure 5. EVAL-AD5110SDZ Evaluation Board Software Main Window

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OPERATING THE SOFTWARE
The main window of the E VA L -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 COMMANDSsection 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
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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EVALUATION BOARD SCHEMATICS AND ARTWORK
10199-006
Figure 6. Schematic of the AD5110 Circuitry

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10199-007
Figure 7. Schematic of SDP Connector

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10199-008
Figure 8. Component Placement Drawing
10199-009
Figure 9. Component Side PCB Drawing

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10199-010
Figure 10. Solder Side PCB Drawing