AD5170 Datasheet, PDF (1/24 Pages) Analog Devices – 256-Position Two-Time Programmable I2C Digital Potentiometer

256-Position Two-Time Programmable
I²C Digital Potentiometer
AD5170
FEATURES
256-position
TTP (two-time programmable) set-and-forget resistance
setting allows second-chance permanent programming
Unlimited adjustments prior to OTP (one-time
programming) 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
Single-supply 2.7 V to 5.5 V
Low temperature coefficient: 35 ppm/°C
Low power, IDD = 6 µA maximum
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 AD5170 is a 256-position, two-time programmable (TTP)
digital potentiometer¹ that employs fuse link technology to
enable two opportunities at permanently programming the
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 electronic adjustment function as mechanical
potentiometers or variable resistors with enhanced resolution,
solid-state reliability, and superior low temperature coefficient
performance.
FUNCTIONAL BLOCK DIAGRAM
AW B
V_DD
GND
AD0
AD1
SDA
SCL
FUSE
LINKS
1
2
RDAC
REGISTER
ADDRESS
DECODE
/₈
SERIAL INPUT
REGISTER
Figure 1.
The AD5170 is programmed using a 2-wire, I²C® compatible
digital interface. Unlimited adjustments are allowed before
permanently (there are actually two opportunities) 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 AD5170 has
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 AD5170 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.}
Rev. A
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