WMS7204

The WMS7204 is a 256-tap, quad-channel non-volatile digital potentiometer available in 10K, 50K and 100K end-to-end resistances. These devices can be used as a three-terminal potentiometer or as a two terminal variable resistor in a wide variety of applications.

The output of each potentiometer of the WMS7204 is determined by the wiper position, which varies linearly between VA and VB terminal according to the content stored in the volatile Tap Register (TR). The settings of the TR can be provided either directly by the user through the industry standard SPI interface, or by the non-volatile memory (NVMEM0~3) where the previous settings are stored. When changes are made to the TR to establish a new wiper position, the value of the setting can be saved into any nonvolatile memory location (NVMEM0~3) by executing a NVMEM save operation. Each channel has its own four non-volatile memory locations (NVMEM0~3) that can be directly written to, and read by, users through the SPI interface. Upon powerup the content of the NVMEM0 is automatically loaded to the Tap Register.

The WMS7204 contains four independent channels in 20-pin PDIP, SOIC and TSSOP packages and can operate over a wide operating voltage range from 2.7V to 5.5V. A selectable output buffer is builtin for each channel for those applications where an output buffer is required.