FEATURES
FUNCTIONAL BLOCK DIAGRAM
AD5231
CS
ADDR
DECODE
CLK
RDAC
REGISTER
A
SDI
SDI
W
SERIAL
INTERFACE
GND
SDO
SDO
WP
EEMEM(0)
DIGITAL
REGISTER
O1
2
EEMEM
CONTROL
RDY
B
DIGITAL
OUTOUT
BUFFER
VSS
PR
Figure 1.
100
RWA (D), RWB (D); (% of Nominal RAB)
Mechanical potentiometer replacement
Instrumentation: gain, offset adjustment
Programmable voltage to current conversion
Programmable filters, delays, time constants
Programmable power supply
Low resolution DAC replacement
Sensor calibration
O2
EEMEM(1)
28 BYTES
USER EEMEM
RWB
RWA
APPLICATIONS
VDD
RDAC
02739-001
1024-position resolution
Nonvolatile memory maintains wiper setting
Power-on refresh with EEMEM setting
EEMEM restore time: 140 µs typ
Full monotonic operation
10 kΩ, 50 kΩ, and 100 kΩ terminal resistance
Permanent memory write protection
Wiper setting readback
Predefined linear increment/decrement instructions
Predefined ±6 dB/step log taper increment/decrement
instructions
SPI®-compatible serial interface
3 V to 5 V single-supply or ±2.5 V dual-supply operation
28 bytes extra nonvolatile memory for user-defined data
100-year typical data retention, TA = 55°C
75
50
25
0
0
256
512
1023
768
CODE (Decimal)
02739-002
Data Sheet
Nonvolatile Memory,
1024-Position Digital Potentiometer
AD5231
Figure 2. RWA (D) and RWB (D) vs. Decimal Code
GENERAL DESCRIPTION
The AD5231 is a nonvolatile memory1, digitally controlled
potentiometer2 with 1024-step resolution. The device performs
the same electronic adjustment function as a mechanical
potentiometer with enhanced resolution, solid state reliability,
and remote controllability. The AD5231 has versatile programming
that uses a standard 3-wire serial interface for 16 modes of
operation and adjustment, including scratchpad programming,
memory storing and restoring, increment/decrement, ±6 dB/step
log taper adjustment, wiper setting readback, and extra EEMEM
for user-defined information, such as memory data for other
components, look-up table, or system identification information.
In scratchpad programming mode, a specific setting can be
programmed directly to the RDAC register that sets the
resistance between Terminals W–A and Terminals W–B. This
setting can be stored into the EEMEM and is transferred
automatically to the RDAC register during system power-on.
The EEMEM content can be restored dynamically or through
external PR strobing, and a WP function protects EEMEM
contents. To simplify the programming, the linear-step increment
or decrement commands can be used to move the RDAC wiper
up or down, one step at a time. The ±6 dB step commands can
be used to double or half the RDAC wiper setting.
The AD5231 is available in a 16-lead TSSOP. The part is
guaranteed to operate over the extended industrial temperature
range of −40°C to +85°C.
The terms nonvolatile memory and EEMEM are used interchangeably.
The terms digital potentiometer and RDAC are used interchangeably.
Rev. D
Document Feedback
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