256-Position SPI/I
2
C Selectable
Digital Potentiometer

AD5161


Rev. 0
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FEATURES
256-position
End-to-end resistance 5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
Compact MSOP-10 (3 mm × 4.9 mm) package
Pin selectable SPI/I
2
C compatible interface
Extra package address decode pin AD0
Full read/write of wiper register
Power-on preset to midscale
Single supply 2.7 V to 5.5 V
Low temperature coefficient 45 ppm/°C
Low power, IDD = 8 µA
Wide operating temperature –40°C to +125°C
SDO output allows multiple device daisy-chaining
Evaluation board available
APPLICATIONS
Mechanical potentiometer replacement in new designs
Transducer adjustment of pressure, temperature, position,
chemical, and optical sensors
RF amplifier biasing
Automotive electronics adjustment
Gain control and offset adjustment

GENERAL OVERVIEW
The AD5161 provides a compact 3 mm × 4.9 mm packaged
solution for 256-position adjustment applications. These devices
perform the same electronic adjustment function as mechanical
potentiometers or variable resistors, with enhanced resolution,
solid-state reliability, and superior low temperature coefficient
performance.
The wiper settings are controllable through a pin selectable SPI
or I
2
C compatible digital interface, which can also be used to
read back the wiper register content. When the SPI mode is
used, the device can be daisy-chained (SDO to SDI), allowing
several parts to share the same control lines. In the I
2
C mode,
address pin AD0 can be used to place up to two devices on the
same bus. In this same mode, command bits are available to
reset the wiper position to midscale or to shut down the device
into a state of zero power consumption.
Operating from a 2.7 V to 5.5 V power supply and consuming
less than 5 µA allows for usage in portable battery-operated
applications.
FUNCTIONAL BLOCK DIAGRAM
WIPER
REGISTER
SDI/SDA
CLK/SCL
DIS
CS/AD0
GND
SDO/NCV
DD
A
W
B
SPI OR I
2
C
INTERFACE

Figure 1.


PIN CONFIGURATION
1
2
3
4
5
10
9
8
7
6
A
B
CS/ADO
SDO/NC
SDI/SDA
DD
AD5161
TOP VIEW
(Not to Scale)
W
V
DIS
GND
CLK/SCL

Figure 2.








Note:
The terms digital potentiometer, VR, and RDAC are used interchangeably.

Purchase of licensed I
2
C components of Analog Devices or one of its sublicensed
Associated Companies conveys a license for the purchaser under the Philips I
2
C
Patent Rights to use these components in an I
2
C system, provided that the system
conforms to the I
2
C Standard Specification as defined by Philips.