Single-Channel, 1024-Position, Digital Rheostat
with SPI Interface and 50-TP Memory
AD5174
FUNCTIONAL BLOCK DIAGRAM
FEATURES
V
DD
Single-channel, 1024-position resolution
10 kΩ nominal resistance
50-times programmable (50-TP) wiper memory
Rheostat mode temperature coefficient: 35 ppm/°C
2.7 V to 5.5 V single-supply operation
2.5 V to 2.75 V dual-supply operation for ac or bipolar
operations
SPI-compatible interface
Wiper setting and memory readback
Power on refreshed from memory
POWER-ON
RESET
AD5174
RDAC
REGISTER
SCLK
SYNC
DIN
A
10
SPI
SERIAL
W
INTERFACE
50-TP
MEMORY
BLOCK
Resistor tolerance stored in memory
Thin LFCSP 10-lead, 3 mm × 3 mm× 0.8 mm package
Compact MSOP, 10-lead, 3 mm × 4.9 mm × 1.1 mm package
SDO
APPLICATIONS
V
EXT_CAP
GND
SS
Figure 1.
Mechanical rheostat replacements
Op-amp: variable gain control
Instrumentation: gain, offset adjustment
Programmable voltage-to-current conversions
Programmable filters, delays, time constants
Programmable power supply
Sensor calibration
GENERAL DESCRIPTION
The AD5174 is a single-channel, 1024-position digital rheostat
that combines industry leading variable resistor performance
with nonvolatile memory (NVM) in a compact package.
The AD5174 device wiper settings are controllable through the
SPI digital interface. Unlimited adjustments are allowed before
programming the resistance value into the 50-TP memory. The
AD5174 does not require any external voltage supply to facili-
tate fuse blow and there are 50 opportunities for permanent
programming. During 50-TP activation, a permanent blow fuse
command freezes the resistance position (analogous to placing
epoxy on a mechanical rheostat).
This device supports both dual-supply operation at 2.5 V to
2.75 V and single-supply operation at 2.7 V to 5.5 V and offers
50-times programmable (50-TP) memory.
The AD5174 is available in a 3 mm × 3mm 10-lead LFCSP
package and in a 10-lead MSOP package. The part is guaranteed
to operate over the extended industrial temperature range of
−40°C to +125°C.
Rev. 0
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