AD5171_15 Datasheet, PDF (1/24 Pages) Analog Devices – 64-Position OTP Digital Potentiometer

64-Position OTP Digital Potentiometer
AD5171
FEATURES
64 position
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
Fast settling time: tS = 5 μs typical in power-up
I²C-compatible digital interface
Computer software replaces microcontroller in factory
programming applications
Full read/write of wiper register
Extra I²C device address pin
Low operating voltage: 2.7 V to 5.5 V
OTP validation check function
Automotive temperature range: −40°C to +125°C
APPLICATIONS
System calibrations
Electronics level settings
Mechanical trimmers and potentiometer replacements
Automotive electronics adjustments
Gain control and offset adjustments
Transducer circuit adjustments
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).
FUNCTIONAL BLOCK DIAGRAM
SCL
A
SDA
I²C INTERFACE
AND
CONTROL LOGIC
W
AD0
B
V_DD
GND
WIPER
REGISTER
FUSE
LINK
AD5171
Figure 1.
W1
8A
V_DD 2 AD5171 7 B
TOP VIEW
GND 3 _{(Not to Scale)} 6 AD0
SCL 4
5 SDA
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.
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.
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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