Dual 50k digital pot with non-volatile wiper storage
The MAX5488EUD+ is a dual 50kΩ digital potentiometer from Analog Devices, configured as a linear-taper potentiometer with 256 tap positions per channel. The wiper setting is stored in non-volatile memory, so the programmed resistance holds across power cycles without a microcontroller re-initializing the part on every boot. Communication is over an SPI interface, which requires four wires (CS, SCK, SDI, SDO) plus the supply and ground.
Wiper resistance and temperature drift — what matters for the analog path
The wiper resistance is 325 Ω typical. In a voltage-divider configuration the wiper resistance adds a fixed offset in series with the load; for a 50 kΩ element the 325 Ω wiper contributes about 0.65 % of the total resistance, which is below the ±25 % absolute tolerance of the overall element. The 256 tap positions give a step size of approximately 195 Ω per tap on the 50 kΩ element. For an audio volume control or a programmable reference divider, the resolution is about 0.39 % of full scale per step. The non-volatile memory is rated for 50,000 wiper-store cycles typical (per the MAX5488 family datasheet), which covers field calibration adjustments over the product lifetime.
Package, footprint, and supply integration
The 14-TSSOP footprint is shared with many other digital potentiometers and general-purpose ICs, so a board layout for this part can often accommodate a pin-compatible alternate without a respin.