Analog Devices EVAL-AD5162SDZ User manual

EVAL-AD5162SDZ User Guide
UG-348
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 AD5162 Digital Potentiometer
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.Rev. 0 | Page 1 of 16
FEATURES
Full-featured evaluation board for the AD5162
Various test circuits
Various ac/dc input signals
PC control via a separately purchased system demonstration
platform (SDP-B)
PC software for control
PACKAGE CONTENTS
EVAL-AD5162SDZ 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 AD5162 data sheet
Electronic version of the UG-348 user guide
GENERAL DESCRIPTION
This user guide describes the evaluation board for evaluating the
AD5162,a dual-channel, 256-position digital potentiometer.
The AD5162 supports a single-supply 2.7 V to 5.5 V operation,
making the device suitable for battery-powered applications and
many other applications. In addition, the AD5162 uses a versa-
tile SPI-compatible serial interface, allowing speeds of up
to 25 MHz.
The EVAL-AD5162SDZ can operate in single-supply mode and
incorporates an internal power supply from the USB.
Complete specifications for the AD5162 part can be found in
the AD5162 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
Figure 1.
EVAL-AD5162SDZ
SYSTEM DEMONSTRATION
PLATFORM
10366-001

UG-348 EVAL-AD5162SDZ User Guide
Rev. 0 | Page 2 of 16
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...............................................................6
Installing the Software ..................................................................6
Running the Software ...................................................................6
Software Operation .......................................................................7
Evaluation Board Schematics and Artwork...................................8
Ordering Information.................................................................... 14
Bill of Materials........................................................................... 14
Related Links............................................................................... 15
REVISION HISTORY
12/11—Revision 0: Initial Version

EVAL-AD5162SDZ User Guide UG-348
Rev. 0 | Page 3 of 16
EVALUATION BOARD HARDWARE
POWER SUPPLIES
The EVA L-AD5162SDZ supports using single power supplies.
The evaluation board can be powered either from the SDP-B
port or externally by the J1-1 and J1-2 connectors, as described
in Table 1.
All supplies are decoupled to ground using 10 µF tantalum and
0.1 µF ceramic capacitors.
Table 1. Maximum and Minimum Voltages of the Connectors
Connector No. Label Voltage
J1-1 EXT Analog positive power supply, VDD.
VDD For single-supply operation, it is 2.7 V
to 5 V.
J1-2 GND Analog ground.
LINK OPTIONS
Several link and switch options are incorporated in the
evaluation board and should be set up before using the board.
Tabl e 2 describes the positions of the links to control the
evaluation board by a PC, via the SDP-B board, using the EVA L -
AD5162SDZ in single-supply mode. The functions of these link
options are described in detail in Table 3 through Tabl e 6.
Table 2. Link Options Setup for SDP-B Control (Default)
Link No. Option
A25 +3.3V
A24 GND
Table 3. Link Functions
Link No. Power Supply Options
A25 VDD This link selects one of the following as the positive power supply:
+5V (from SDP-B).
+3.3V (from SDP-B).
EXT (external supply from the J1-1 connector).
A24 VSS This link should be connected to GND (analog ground).

UG-348 EVAL-AD5162SDZ User Guide
Rev. 0 | Page 4 of 16
TEST CIRCUITS
The EVA L-AD5162SDZ incorporates several test circuits to
evaluate the AD5162 performance.
DAC
RDAC1 can be operated as a digital-to-analog converter (DAC),
as shown in Figure 2.
Figure 2. DAC
Tabl e 4 shows the options available for the voltage references.
Table 4. DAC Voltage References
Terminal Link Options Description
A1 A20 AC + DC Connects Terminal A1 to
(VDD − VSS)/2.
VDD Connects Terminal A1 to VDD.
W1 BUF_W1 Connects Terminal W1 to an
output buffer.
B1 A21 DC Connects Terminal B1 to
(VDD − VSS)/2.
GND Connects Terminal B1 to
analog ground.
The output voltage is defined in Equation 1.
256
)( WB1
B1
A1
OUT
R
VVV ×−=
(1)
where:
RWB1 is the resistor between the W1 and B1 terminals.
VA1 is the voltage applied to the A1 terminal (A20 link).
VB1 is the voltage applied to the B1 terminal (A21 link).
However, by using the R34 and R35 external resistors, the user
can reduce the voltage of the voltage references. In this case, use
the A1 and B1 test points to measure the voltage applied to the
A0 and B0 terminals and recalculate VA0 and VB0 in Equation 1.
AC Signal Attenuation
RDAC1 can be used to attenuate an ac signal, which must be
provided externally using the AC_INPUT connector, as shown
in Figure 3.
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 Tabl e 5.
Table 5. AC Signal Attenuation Link Options
Link Options Conditions
A20 AC + DC No dc offset voltage.
AC signal is outside the voltage supply rails
due to the dc offset voltage.
DC offset voltage ≠ VDD/2.1
AC All other conditions.
A21 DC Use in conjunction with ac + dc link.
GND All other conditions.
1Recommended to ensure optimal total harmonic distortion (THD) performance.
The signal attenuation is defined in Equation 2.







+
×=
−− ENDTOEND
WWB1
R
RR
nAttenuatio log20)dB(
(2)
where:
RWB1is the resistor between the W1 and B1 terminals.
RWis the wiper resistance.
REND-TO-END is the end-to-end resistance value.
In addition, R36 can be used to achieve a pseudologarithmic
attenuation. To do so, adjust the R36 resistor until a desirable
transfer function is found.
W1_BUF
A1
RDAC1
AC + DC
VDD
A1
B1 BUF_W1
GND
DC
2
VDD – VSS
VDD
2
VDD – VSS
R34
R35
W1
W1
B1
10366-002
W1_BUF
A1
RDAC1
AC + DC
AC_INPUT
AC
A1
B1 BUF_W1
GND
2
V
DD
– V
SS
R34
R35
W1
W1
B1
1µF
R36
DC
2
V
DD
– V
SS
10366-003

EVAL-AD5162SDZ User Guide UG-348
Rev. 0 | Page 5 of 16
Signal Amplifier
RDAC2 can be operated as an inverting or noninverting signal
amplifier supporting linear or pseudologarithmic gains. Tabl e 6
shows the available configurations.
The noninverting amplifier with linear gain is shown in Figure 4,
and the gain is defined in Equation 3.
R38
R
GWB2
+=1
(3)
where RWB2 is the resistor between the W2 and B2 terminals.
Figure 4. Linear Noninverting Amplifier
R42 can be used to set the maximum and minimum gain limits.
The inverting amplifier with linear gain is shown in Figure 5,
and the gain is defined in Equation 4.
Note that the input signal, VIN, must be negative.
R38
R
G
WB2
−=
(4)
where RWB2 is the resistor between the W2 and B2 terminals.
Figure 5. Linear Inverting Amplifier
Table 6. Amplifier Selection Link Options
Amplifier Gain Link Label VIN Range
Noninverting
Linear
A27
LINEAR
0 V to V
DD
A29 NON-INV
A30 NON-INV
Inverting
Linear
A27
LINEAR
−V
DD
to 0 V
A29 INV
A30 INV
VIN
RDAC2
B2 R42
W2 B2
W2
VOUT
OAVOUT
C1
10nF
R41
1.7kΩ
R38
2.7kΩ
10366-004
VIN
RDAC2
B2 R42
W2 B2
W2
VOUT
OAVOUT
C1
10nF
R41
1.7kΩ
R38
2.7kΩ
10366-006

UG-348 EVAL-AD5162SDZ User Guide
Rev. 0 | Page 6 of 16
EVALUATION BOARD SOFTWARE
INSTALLING THE SOFTWARE
The EVA L-AD5162SDZ evaluation kit includes evaluation
board software provided on a CD. The software is compatible
with Windows® XP, Windows Vista, and Windows 7 (both
32 bits and 64 bits).
Install the software before connecting the SDP-B board to the USB
port of the PC to ensure that the SDP-B 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 installation is completed, power up the evaluation
board as described in the Power Supplies section.
4. Connect the E VA L -AD5162SDZ to the SDP-B board and the
SDP-B board to the PC using the USB cable included in the
evaluation kit.
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 > AD5162 Eval Board.
RUNNING THE SOFTWARE
To run the program, do the following:
1. Click Start > All Programs > Analog Devices > AD5162 >
AD5162 Eval Board.
2. If the SDP-B board is not connected to the USB port when
the software is launched, a connectivity error displays (see
Figure 6). Simply connect the evaluation board to the USB
port of the PC, wait a few seconds, click Rescan, and follow
the instructions.
Figure 6. Pop-Up Window Error
The main window of the E VAL -AD5162SDZ evaluation
software then opens, as shown in Figure 7.
Figure 7. EVAL-AD5162SDZ Evaluation Board Software Main Window
10366-009
10366-010

EVAL-AD5162SDZ User Guide UG-348
Rev. 0 | Page 7 of 16
SOFTWARE OPERATION
The main window of the E VA L -AD5162SDZ software is
divided into the following sections: RDAC1, RDAC2, and
REGISTER ACCESS.
RDAC1 and RDAC2 can be used to update the RDAC registers
by entering a desirable value into the text box and clicking
WRITE.
REGISTER ACCESS has the following options:
•SEND DATA is a customized I2C data-word that can be
sent by manually switching the scroll bars from 0 to 1 or
from 1 to 0, as desired, and then clicking SEND DATA.
In addition, the scroll bars are updated on each write
transfer, showing the command sent to the part.
•Clicking EXIT closes the program but does not reset the part.

UG-348 EVAL-AD5162SDZ User Guide
Rev. 0 | Page 8 of 16
EVALUATION BOARD SCHEMATICS AND ARTWORK
Figure 8. Schematic of Multiboard Digital Potentiometers
10366-011
MULTICHANNEL
I2C
SPI
U/D
0x5E
0x5E
0x58 0x5A
1AGND2 2B2 3A2 7A4 8W4
9
DGND
10
SHDN
11
SYNC
12
DIN
5AGND4 6B4 4W2
21 AGND1 19 A3
13
SDO
14
SCLK
15
RESET
16
VDD
17 AGND3 18 W3 24 B1 22 W1 23 A1 20 B3
U6 AD8403
1W1 2B1 3A1 7B2 8A2 9
SDA
10
VSS
11 A3 12 B3 5
WP
6W2
4
AD0
19 W4 13 W3
14
SCL
15
DGND
16
AD1
17 A4 18 B4
20
VDD
U7 AD5254
1
NC
2
NC
3
GND
7
SHDN
8
DIN
9
SCLK
10
SDO
11
VSS
12
NC
5
RESET
6
VDD
4
SYNC
21 B2 19 A2 13 B3 14 W3 15 A3 16 B1 17 W1 18 A1 24 B4 22 A4 23 W4 20 W2
U8 AD5204
4
GND
5
VDD
6
SCL
8A2
7
SDA
1B1 2A1 3W2 9B2
10 W1
U1
AD5243
4
GND
5
VDD
6
SCLK
8
SYNC 7
DIN
1B1 2A1 3W2 9B2
10 W1
U2
AD5162
4
GND
5
VDD
6
SCL
8A2
7
SDA
1B1 2A1 3W2 9B2
10 W1
U3
AD5172_SOCKET
1
O1
2
SCLK 3
DIN
7A1 8W1 9B1
10 A2 11 W2 12 B2
5
GND 6
VSS
4
SDO
19
VDD
13 B3
14 W3
15 A3 16 B4 17 W4 18 A4 20
WP
21
RESET
22
SYNC
23
RDY
24
O2
U4 AD5233
4
VSS
5W2 6A2
8
GND
7B2 1B1 2A1 3W1
9
MODE 10
DACSEL 11
U/D 12 CLK 13
CS
14
VDD
U5
AD5222
4W1 5B1 6A1
8
VSS
7
SDA
1
VDD
2
AD0
3
WP
9
SCL
10
DGND
11
AD1
12 A3 13 B3 14 W3
U9
AD5252
4
GND 5
VSS
6A1 8B1 7W1
1
SCLK 2
DIN 3
SDO
9B2
10 W2 11 A2
12
VDD
13
WP 14
RESET
15
SYNC
16
RDY
U10
AD5232
4
GND 5
VSS
6A1 8B1 7W1
1
SCLK 2
DIN 3
SDO
9B2
10 W2 11 A2
12
VDD
13
WP 14
RESET
15
SYNC
16
RDY
U11
AD5235
4
GND 5
VSS
6V1 8B1 7W1
1
SCLK 2
DIN 3
SDO
9B2
10 W2 11 V2
12
VDD
13
WP 14
RESET
15
SYNC
16
RDY
U12
ADN2850
A1
W1-1
B1 A2
W2-1
B2 A3
W3-1
B3 A4
W4-1
B4
SHDN
RESET SCLK SDO DIN SYNC-1
A1
W1-8
B1 A2
W2-8
B2 A3
W3-8
B3 A4
W4-8
B4
SDA SCL WP
A1
W1-5
B1 A2
W2-5
B2
RDY SDO DIN SCLK SYNC-5
WP RESET
VDD
VDD
VSS
VSS
VDD
A1
W1-4
B1
W2-4
B2
SYNC-4
DIN SCLK
VDD
A1
W1-2
B1 A2
W2-2
B2 A3
W3-2
B3 A4
W4-2
B4
SYNC-2
SCLK DIN SDO RESET SHDN
VDD
VSS
A1
W1-3
B1 A2
W2-3
B2 A3
W3-3
B3 A4
W4-3
B4
O1 O2 RDY SDO SCLK DIN SYNC-3
RESET WP
VDD
VSS
W1-6
B1
W2-6
B2 V1 V2
RDY SDO DIN SCLK SYNC-6
WP RESET
VDD
VSS
A1
W1-9
B1 A2
W2-9
B2
A1
W1-7
B1 A2
W2-7
B2
RDY SDO DIN SCLK SYNC-7
WP RESET
VDD
VSS
VDD
SCL SDA WP
VSS
VDD
A1
W1-10
B1 A2
W2-10
B2
SDA SCL
A1
W1-11
B1 A2
W2-11
B2
SDA SCL
VDD VDD
A1
W1-12
B1 A2
W2-12
B2
CS
CLK U/D DACSEL MODE
VDD
VSS

EVAL-AD5162SDZ User Guide UG-348
Rev. 0 | Page 9 of 16
Figure 9. Schematic of Multiboard RDAC1 Circuits
Figure 10. Schematic of Multiboard RDAC2 Circuits
VDD
DAC + FLOATING DAC + BW
PSEUDOLOGATTENUATOR
B1
AC
AD8403-1
AD5204-1
AD5233-1
AD5162-1
AD5232-1
ADN2850-1
AD5235-1
AD5254-1
AD5252-1
AD5172
AD5243-1
W1
AD5222-1
+
-1
2
3U14-A
AD8618ARZ
BUF-W1 W1_BUF
R34
R35
R39
R40
AC_INPUT C3
A1
B1
R36
A
B
C
A20
A
B
C
A21
R3
R4
3+
2-
1
U15-A
AD8652AR
5+
6-7
U15-B
AD8652AR
8
V+
4
V-
U15-C
W1-1
W1-2
W1-3
W1-4
W1-5
W1-6
W1-7
W1-8
W1-9
W1-10
W1-11
W1
W1-12
VDD
VSS
A1
B1
VSS
VDD
VSS
VDD
VSS
10366-012
AC + DC
10366-013
INVERTINGANDNON-INVERTINGWITHLINEARANDPSEUDO-LOGGAIN
DIGIPOT
PSEUDOLOG
LINEAR
NON-INVERTING
INVERTING
NON-INVERTING
INVERTING
CIRCUIT CONNECTION
VIN
GND
+
-
7
6
5U14-B
AD8618ARZ
AD8403 -2
AD5204 -2
AD5233 -2
AD5162 -2
AD5232 -2
ADN2850 -2
AD5235 -2
AD5254 -2
AD5252 -2
AD5172 -2
AD5243 -2
AD5322 -2
W2
VOUT
R38
J2-1
J2-2
R41
R42
R43
B2
A2
OAVOUT
C1
BA
A29
BA
A27
BA
A30
W2-1
W2-2
W2-3
W2-4
W2-5
W2-6
W2-7
W2-8
W2-9
W2-10
W2-11
W2-12
W2
A2
B2W2

UG-348 EVAL-AD5162SDZ User Guide
Rev. 0 | Page 10 of 16
Figure 11. Schematic of AD5162 Power Supplies and Other Channels
10366-014
POWER-SUPPLIES
EXT VDD
+5V
+3.3V
GND
EXT VSS
GND
CHANNELS 3 AND 4 POWER-SUPPLY
DIGITAL PINS CURRENT MONITOR
+C24
10uF C25
0.1uF
C26 0.1uF
+C27
10uF
J1-1
J1-2 J1-3
A
B C
A25
A B
A24
+ -14
13 12 U14-D
AD8618ARZ
AD8403-4 AD5204-4 AD5233-4 AD5254-4
+ -8
9
10 U14-C
AD8618ARZ
AD8403-3 AD5204-3 AD5233-3 AD5254-3
BUF-4
BUF-3
A4
VOUT4
B4
A3
VOUT3
B3
W4
W3
O2
O1
V2 V1
C2 0.1uF
C4 0.1uF
VSS
VDD
+3.3V +5V
W4-1 W4-2 W4-3 W4-8
W3-1 W3-2 W3-3 W3-8
B4
A3
B3
A4
O1
O2
V1
V2