64-Position OTP Digital Potentiometer
AD5171
FUNCTIONAL BLOCK DIAGRAM
FEATURES
64 position
SCL
A
One-time programmable (OTP) set-and-forget resistance
setting—low cost alternative over EEMEM
Unlimited adjustments prior to OTP activation
5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ end-to-end resistance
Low temperature coefficient: 5 ppm/°C in potentiometer mode
Low temperature coefficient: 35 ppm/°C in rheostat mode
Compact standard 8-lead SOT-23 package
Low power: IDD = 10 μA maximum
2
I C INTERFACE
SDA
AD0
AND
CONTROL LOGIC
W
B
WIPER
REGISTER
V
DD
GND
FUSE
LINK
Fast settling time: tS = 5 μs typical in power-up
I2C-compatible digital interface
AD5171
Computer software replaces microcontroller in factory
programming applications
Figure 1.
Full read/write of wiper register
W
1
2
3
4
8
7
6
5
A
B
Extra I2C device address pin
V
AD5171
DD
TOP VIEW
Low operating voltage: 2.7 V to 5.5 V
OTP validation check function
GND
SCL
AD0
SDA
(Not to Scale)
Automotive temperature range: −40°C to +125°C
Figure 2. Pin Configuration
When this permanent setting is achieved, the value does not
change regardless of supply variations or environmental stresses
under normal operating conditions. To verify the success of
permanent programming, Analog Devices, Inc., patterned the
OTP validation such that the fuse status can be discerned from
two validation bits in read mode.
APPLICATIONS
System calibrations
Electronics level settings
Mechanical trimmers and potentiometer replacements
Automotive electronics adjustments
Gain control and offset adjustments
Transducer circuit adjustments
For applications that program the AD5171 in factories, Analog
Devices offers device programming software that operates
across Windows® 95 to XP platforms, including Windows NT.
This software application effectively replaces the need for external
I2C controllers or host processors and, therefore, significantly
reduces the development time of the users.
Programmable filters up to 1.5 MHz BW1
GENERAL DESCRIPTION
The AD5171 is a 64-position, one-time programmable (OTP)
digital potentiometer2 that uses fuse link technology to achieve
the memory retention of the resistance setting function. OTP is
a cost-effective alternative over the EEMEM approach for users
who do not need to reprogram new memory settings in the
digital potentiometer. This device performs the same electronic
adjustment function as most mechanical trimmers and variable
resistors. The AD5171 is programmed using a 2-wire, I2C®-
compatible digital control. It allows unlimited adjustments
before permanently setting the resistance value. During the
OTP activation, a permanent fuse blown command is sent after the
final value is determined, freezing the wiper position at a given
setting (analogous to placing epoxy on a mechanical trimmer).
An AD5171 evaluation kit includes the software, connector, and
cable that can be converted for factory programming applications.
The AD5171 is available in a compact 8-lead SOT-23 package.
All parts are guaranteed to operate over the automotive temper-
ature range of −40°C to +125°C. Besides its unique OTP feature,
the AD5171 lends itself well to other general-purpose digital
potentiometer applications due to its temperature performance,
small form factor, and low cost.
1 Applies to 5 kΩ parts only.
2 The terms digital potentiometer and RDAC are used interchangeably.
Rev. D
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responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
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