256-Position, One-Time Programmable,
Dual-Channel, I2C Digital Potentiometers
AD5172/AD5173
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
A1
W1
B1
A2
W2
B2
2-channel, 256-position potentiometers
One-time programmable (OTP) set-and-forget resistance
setting provides a low cost alternative to EEMEM
Unlimited adjustments prior to OTP activation
OTP overwrite allows dynamic adjustments with user-
defined preset
FUSE
LINKS
V
DD
1
2
End-to-end resistance: 2.5 kΩ, 10 kΩ, 50 kΩ, and 100 kΩ
Compact 10-lead MSOP: 3 mm × 4.9 mm
Fast settling time: tS = 5 μs typical on power-up
Full read/write of wiper register
Power-on preset to midscale
Extra package address decode pins: AD0 and AD1 (AD5173)
Single supply: 2.7 V to 5.5 V
RDAC
REGISTER 1
RDAC
REGISTER 2
GND
8
SDA
SCL
SERIAL INPUT
REGISTER
Figure 1. AD5172 Functional Block Diagram
Low temperature coefficient: 35 ppm/°C
Low power: IDD = 6 μA maximum
W1
B1
W2
B2
Wide operating temperature: −40°C to +125°C
APPLICATIONS
FUSE
LINKS
Systems calibration
Electronics level setting
V
DD
1
2
Mechanical trimmers replacement in new designs
Permanent factory PCB setting
Transducer adjustment of pressure, temperature, position,
chemical, and optical sensors
RDAC
REGISTER 1
RDAC
REGISTER 2
GND
AD0
AD1
ADDRESS
DECODE
8
RF amplifier biasing
Automotive electronics adjustment
Gain control and offset adjustment
SDA
SCL
SERIAL INPUT
REGISTER
Figure 2. AD5173 Functional Block Diagram
GENERAL DESCRIPTION
The AD5172/AD5173 are dual-channel, 256-position, one-time
programmable (OTP) digital potentiometers1 that employ fuse
link technology to achieve memory retention of resistance
settings. OTP is a cost-effective alternative to EEMEM for users
who do not need to program the digital potentiometer setting
in memory more than once. These devices perform the same
electronic adjustment function as mechanical potentiometers or
variable resistors but with enhanced resolution, solid-state reliabil-
ity, and superior low temperature coefficient performance.
before permanently setting the resistance value. During OTP
activation, a permanent blow fuse command freezes the wiper
position (analogous to placing epoxy on a mechanical trimmer).
Unlike traditional OTP digital potentiometers, the AD5172/
AD5173 have a unique temporary OTP overwrite feature that
allows for new adjustments even after a fuse is blown. However,
the OTP setting is restored during subsequent power-up condi-
tions. This allows users to treat these digital potentiometers as
volatile potentiometers with a programmable preset.
The AD5172/AD5173 are programmed using a 2-wire, I2C®-
compatible digital interface. Unlimited adjustments are allowed
1 The terms digital potentiometer, VR, and RDAC are used interchangeably.
Rev. H
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