The MAX5477/MAX5478/MAX5479 are nonvolatile, dual, linear-taper, digital potentiometers that perform the function of a mechanical potentiometer, but replace the mechanics with a simple 2-wire digital interface. Each device performs the same function as a discrete potenti- tiometer or variable resistor and has 256 tap points. The devices feature an internal, nonvolatile EEPROM used to store the wiper position for initialization during power-up. A write-protect feature prevents accidental overwrites of the EEPROM. The fast-mode I2C-compati- ble serial interface allows communication at data rates up to 400kbps, minimizing board space and reducing interconnection complexity in many applications. Three address inputs allow a total of eight unique address combinations. The MAX5477/MAX5478/MAX5479 provide three nomi- nal resistance values: 10kΩ (MAX5477), 50kΩ (MAX5478), or 100kΩ (MAX5479). The nominal resistor temperature coefficient is 70ppm/°C end-to-end and 10ppm/°C ratiometric. The low temperature coefficient makes the devices ideal for applications requiring a low- temperature-coefficient variable resistor, such as low- drift, programmable gain-amplifier circuit configurations. The MAX5477/MAX5478/MAX5479 are available in 16- pin 3mm x 3mm x 0.8mm thin QFN and 14-pin 4.4mm x 5mm TSSOP packages. These devices operate over the extended -40°C to +85°C temperature range. Applications include Mechanical Potentiometer Replacement Low-Drift Programmable-Gain Amplifiers Volume Contro
The MAX5477/78/79 series replaces mechanical potentiometers with a dual, 256‑tap, non‑volatile digital interface. Each device provides 256 tap points and stores the wiper position in an internal EEPROM that is recalled on power‑up. The series supports a fast 400 kbps I²C‑compatible serial interface and three address inputs for up to eight unique devices on a bus.
These parts are offered in 16‑pin thin QFN and 14‑pin TSSOP packages, operate from +2.7 V to +5.25 V, and are rated for –40 °C to +85 °C. Nominal resistance values are 10 kΩ (MAX5477), 50 kΩ (MAX5478) and 100 kΩ (MAX5479), making them suitable for applications such as mechanical potentiometer replacement, low‑drift programmable‑gain amplifiers, volume control, and LCD contrast control.
| Number of taps | 256 |
|---|---|
| Supply voltage range | +2.7 V to +5.25 V |
| Operating temperature range | -40 °C to +85 °C |
| Package types | 16‑pin Thin QFN, 14‑pin TSSOP |
| Static supply current | 1 pA (max) |
Three address inputs allow a total of eight unique address combinations.