256-Position, 1% Resistor Tolerance Error, SPI Interface and 50-TP Memory Digital Rheostat

The AD5270/AD5271 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.

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.

Applications

* Mechanical potentiometer 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

* Single-channel, 1024-/256-position resolution

* 20 kΩ, 50 kΩ and 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