3-Channel, Dual 512- and Single 128-Position IC Digital Potentiometer with Nonvolatile Memory and IC Interface

The AD5255 provides a dual 512 position and a single 128 position digitally controlled variable resistors1 (VR) in a TSSOP package. This device performs the same electronic adjustment function as a potentiometer, trimmer, or VR. Each VR offers a completely programmable value of resistance between the A terminal and the wiper or the B terminal and the wiper. The fixed A-to-B terminal resistance of 25 kΩ or 250 kΩ has a 1% channel-to-channel matching tolerance and a nominal temperature coefficient of 35 ppm/°C.

Wiper position programming, EEPROM2 reading, and EEPROM writing is conducted via the standard 2-wire I2C interface. Pre-vious/default wiper position settings can be stored in memory and refreshed upon system power-up.

Additional features of the AD5255 include preprogrammed linear and logarithmic increment/decrement wiper changing. The actual resistor tolerances are stored in EEPROM, so the actual end-to-end resistance is known, which is valuable for calibration in precision applications.

The AD5255 is available in a 24-lead TSSOP. All parts are guaranteed to operate over the extended industrial temperature range of −40°C to +85°C.

1 The terms programmable resistor, variable resistor, RDAC, and digital potentiometer are used interchangeably.

2 The terms nonvolatile memory, EEMEM, and EEPROM are used interchangeably.

Applications

* Mechanical potentiometer replacement

* RGB LED backlight controls

* White LED brightness adjustment

* Programmable gain and offset controls

* Programmable filters

* I2C-compatible serial interface * 2.7 V to 5.5 V single-supply operation

±2.25 V to ±2.75 V dual-supply operation