ISL22317

The digitally controlled potentiometer is implemented with a combination of resistor elements and CMOS switches. The position of the wiper is controlled by the user through the I²C bus interface. The potentiometer has an associated volatile Wiper Register (WR) and a non-volatile Initial Value Register (IVR) that can be directly written to and read by the user. The contents of the WR control the position of the wiper. At power up, the device recalls the contents of the DCP's IVR to the WR. The highly precise ISL22317 features a low end-to-end temperature coefficient of TC_Ref ±10ppm/°C and precise resistance selection. It maintains less than ±1% typical variance from the ideal resistance at each wiper position providing 99% accuracy of selected resistance value. This highly accurate DCP eliminates the need for complex algorithms to guarantee precision. The ISL22317 allows the user to dial in an accurate resistance and the EEPROM memory stores the set value for life, or until changed by the user. An external 0. 5% or better reference resistor must be attached to the ISL22317. The ISL22317 will mirror both the precise resistance and temperature coefficient of the external resistor. The DCP can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing.