AD5172 Datasheet, PDF (1/24 Pages) Analog Devices – 256-Position One-Time Programmable Dual-Channel I2C Digital Potentiometers

256-Position One-Time Programmable
Dual-Channel I²C Digital Potentiometers
AD5172/AD5173
FEATURES
2-channel, 256-position
OTP (one-time programmable) set-and-forget resistance
setting, low cost alternative to EEMEM
Unlimited adjustments prior to OTP activation
OTP overwrite allows dynamic adjustments with user
defined preset
End-to-end resistance: 2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
Compact MSOP-10 (3 mm × 4.9 mm) package
Fast settling time: tS = 5 µs typ in 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
Low temperature coefficient: 35 ppm/°C
Low power, IDD = 6 µA max
Wide operating temperature: –40°C to +125°C
Evaluation board and software are available
Software replaces µC in factory programming applications
APPLICATIONS
Systems calibration
Electronics level setting
Mechanical Trimmers® replacement in new designs
Permanent factory PCB setting
Transducer adjustment of pressure, temperature, position,
chemical, and optical sensors
RF amplifier biasing
Automotive electronics adjustment
Gain control and offset adjustment
GENERAL OVERVIEW
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
setting. 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. This device performs the same elec-
tronic adjustment function as mechanical potentiometers or
variable resistors with enhanced resolution, solid-state reliabil-
ity, and superior low temperature coefficient performance.
The AD5172/AD5173 are programmed using a 2-wire, I²C
compatible digital interface. Unlimited adjustments are allowed
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).
Rev. A
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However, no 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 license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
FUNCTIONAL BLOCK DIAGRAMS
A1 W1 B1
A2 W2 B2
V_DD
GND
SDA
SCL
FUSE
LINKS
1
2
RDAC
REGISTER 1
RDAC
REGISTER 2
/₈
SERIAL INPUT
REGISTER
Figure 1. AD5172
W1 B1
W2 B2
V_DD
GND
FUSE
LINKS
1
2
RDAC
REGISTER 1
RDAC
REGISTER 2
AD0
AD1
ADDRESS
/ ^DECODE
8
SDA
SCL
SERIAL INPUT
REGISTER
Figure 2. AD5173
Unlike traditional OTP digital potentiometers, the AD5172/
AD5173 have a unique temporary OTP overwrite feature that
allows for new adjustments even after the fuse has been blown.
However, the OTP setting is restored during subsequent power-
up conditions. This feature allows users to treat these digital
potentiometers as volatile potentiometers with a programmable
preset.
For applications that program the AD5172/AD5173 at the
factory, Analog Devices offers device programming software
running on Windows® NT®, 2000, and XP® operating systems.
This software effectively replaces any external I²C controllers,
thus enhancing the time-to-market of the user’s systems.
1_{The terms digital potentiometer, VR, and RDAC are used interchangeably.}
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