PRELIMINARY TECHNICAL DATA
a
FEATURES
Nonvolatile Memory Preset Maintains Wiper Settings
AD5231 Single, 1024 Position Resolution
AD5232 Dual, 256 Position Resolution
AD5233 Quad, 64 Position Resolution
10K, 50K, 100K Ohm Terminal Resistance
Linear or Log taper Settings
Increment/Decrement Commands, Push Button Command
SPI Compatible Serial Data Input with Readback Function
+3 to +5V Single Supply or 鹵2.5V Dual Supply Operation
User EEMEM nonvolatile memory for constant storage
APPLICATIONS
Mechanical Potentiometer Replacement
Instrumentation: Gain, Offset Adjustment
Programmable Voltage to Current Conversion
Programmable Filters, Delays, Time Constants
Line Impedance Matching
Power Supply Adjustment
DIP Switch Setting
CS
CLK
SDI
Nonvolatile Memory
Digital Potentiometers
AD5231/AD5232/AD5233
FUNCTIONAL BLOCK DIAGRAMS
AD 523 1
AD DR
D ECO D E
V
DD
A
1
W
1
SDI
S E R IA L
IN T E R F A C E
RDAC1
R E G IS T E R
RDAC1
GND
EEMEM1
B
1
SDO
WP
RDY
PR
SDO
EEMEM
C ON TR O L
28 B Y TE S
USER EEMEM
D IG IT A L 2
R E G IS T E R
2
D IG IT A L
O UTPUT
BU FFER
O
1
O
2
V
SS
EEMEM2
CS
C LK
SDI
SDI
S E R IA L
IN T E R F A C E
AD D R
D EC O D E
A D 5232
RDAC1
R E G IS T E R
RDAC1
V
DD
A
1
W
1
GENERAL DESCRIPTION
The AD5231/AD5232/AD5233 family provides a single-
/dual-/quad-channel, digitally controlled variable resistor (VR)
with resolutions of 1024/256/64 positions respectively. These
devices perform the same electronic adjustment function as a
potentiometer or variable resistor. The AD523X鈥檚 versatile
programming via a Micro Controller allows multiple modes of
operation and adjustment.
In the direct program mode a predetermined setting of the
RDAC register can be loaded directly from the micro controller.
Another key mode of operation allows the RDAC register to be
refreshed with the setting previously stored in the EEMEM
register. When changes are made to the RDAC register to
establish a new wiper position, the value of the setting can be
saved into the EEMEM by executing an EEMEM save
operation. Once the settings are saved in the EEMEM register
these values will be transferred automatically to the RDAC
register to set the wiper position at system power ON. Such
operation is enabled by the internal preset strobe and the preset
can also be accessed externally.
The basic mode of adjustment is the increment and decrement
command controlling the present setting of the Wiper position
setting (RDAC) register. An internal scratch pad RDAC register
can be moved UP or DOWN, one step of the nominal terminal
resistance between terminals A-and-B. This linearly changes the
wiper to B terminal resistance (R
WB
) by one position segment of
the device's end-to-end resistance (R
AB
). For
exponential/logarithmic changes in wiper setting, a left/right
shift command adjusts levels in +/-6dB steps, which can be
useful for sound and light alarm applications.
The AD523X are available in the thin TSSOP package. All
parts are guaranteed to operate over the extended industrial
temperature range of -40擄C to +85擄C.
REV PrF, 22 MAR '01
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use; nor for any infringements of patents
or other rights of third parties, which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of Analog Devices.
GND
EEM EM 1
B
1
RDAC2
A
2
W
2
SDO
WP
RDY
PR
SDO
EEM EM
CONTRO L
14 BYTES
USER EEM EM
RDAC2
R E G IS T E R
EEM EM 2
B
2
V
SS
CS
C LK
SDI
SDI
S E R IA L
IN T E R F A C E
AD D R
D EC O D E
A D 5233
RDAC1
R E G IS T E R
RDAC1
V
DD
A
1
W
1
EEM EM 1
B
1
RDAC2
A
2
W
2
SDO
WP
RDY
GND
SDO
EEM EM
CONTRO L
RDAC2
R E G IS T E R
EEM EM 2
11 BY T ES
USER EEM EM
B
2
O
1
O
2
D IG IT A L
OUTPUT
BUFFER
2
RDAC3
R E G IS T E R
RDAC3
A
3
W
3
EEM EM 3
B
3
RDAC4
A
4
W
4
D IG IT A L 5
R E G IS T E R
PR
EEM EM 5
RDAC4
R E G IS T E R
EEM EM 4
B
4
V
SS
One Technology Way, P.O. Box 9106,
Norwood, MA 02062-9106 U
.
S
.
A
.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax:617/326-8703
漏 Analog Devices, Inc., 1999
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