256-tap SPI digital pot with non-volatile wiper storage
The MAX5423ETA+T is a single-channel, 256-tap digital potentiometer from Analog Devices with a 100k end-to-end resistance. The linear taper means each step changes the resistance by the same increment — 100k / 256 ≈ 390 ohms per step — making it a straight choice for precision voltage dividers and programmable gain stages. The wiper position is stored in non-volatile memory and restored at power-up, so the calibration holds across power cycles without a separate EEPROM or microcontroller shadow register. The SPI interface writes the wiper register directly; no I²C address conflicts to manage on a shared bus.
Supply range, temp grade, and wiper resistance budget
The 35 ppm/°C temperature coefficient is tight enough that the resistance drift across the full temperature span stays under 0.35% — relevant if this pot sets a bias voltage or a comparator threshold. The 325 ohm wiper resistance adds a series offset in the divider; for a 100k string the error is 0.325% at the extremes, which is negligible for most gain-setting applications but worth budgeting in a precision reference divider.
Package and board integration
Supplied in an 8-WDFN with exposed pad (8-TDFN, 3x3 mm). Without that thermal connection, the part's power dissipation is limited to the plastic package's free-air rating. Cut Tape works for prototype builds and small-batch assembly.