AD5270 Datasheet, PDF (1/24 Pages) Analog Devices – 1024-/256-Position, 1% Resistor Tolerance Error, SPI Interface and 50-TP Memory Digital Rheostat

Data Sheet
1024-/256-Position, 1% Resistor Tolerance Error,
SPI Interface and 50-TP Memory Digital Rheostat
AD5270/AD5271
FEATURES
Single-channel, 1024-/256-position resolution
20 kΩ, 50 kΩ, 100 kΩ nominal resistance
Maximum ±1% nominal resistor tolerance error
50-times programmable (50-TP) wiper memory
Rheostat mode temperature coefficient: 5 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 readback
Power on refreshed from 50-TP 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
APPLICATIONS
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 AD5270/AD5271¹ are single-channel, 1024-/256-position
digital rheostats that combine industry leading variable resistor
performance with nonvolatile memory (NVM) in a compact
package.
The AD5270/AD5271 ensure less than 1% end-to-end resistor
tolerance error and offer 50-times programmable (50-TP) memory.
The guaranteed industry leading low resistor tolerance error
feature simplifies open-loop applications as well as precision
calibration and tolerance matching applications.
FUNCTIONAL BLOCK DIAGRAM
V_DD
POWER-ON
RESET
AD5270/AD5271
RDAC
SCLK
REGISTER
A
SERIAL
10/8
SYNC
INTERFACE
W
DIN
SDO
50-TP
MEMORY
BLOCK
V_SS
EXT_CAP
Figure 1.
GND
The AD5270/AD5271 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 AD5270/AD5271 do not require any
external voltage supply to facilitate 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 trimmer).
The AD5270/AD5271 are available in a 3 mm × 3 mm, 10-lead
LFCSP package and in a 10-lead MSOP package. The parts are
guaranteed to operate over the extended industrial temperature
range of −40°C to +125°C.
1 _{Protected by U.S.Patent Number 7688240}
Rev. F
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