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.

Features

? Precision Digitally Controlled Potentiometer

- 99 Typical Accuracy Of Resistance Over Operational

Conditions

- Zero-Compensated Wiper Resistance

? Integrated Digitally Controlled Potentiometer

- 128-Tap Positions

- I2C Serial Interface

- Pin Selectable Slave Address

- 10kΩ, 50kΩ and 100kΩTotal Resistance

- Monotonic Over-Temperature

- Non-Volatile EEPROM Storage of Wiper Position

- 0 to VCC Terminal Voltage

? Single 2.7V to 5.5V Supply

? High Reliability

- 50 Years Retention @ ≤ +55°C

- 15 Years Retention @ +125°C

- 1,000,000 Cycles Endurance

? 3mmx3mm Thin DFN Package – 0.75mm Max Thickness,

0.65mm Pitch

? Pb-Free (RoHS Compliant)

Applications

? Setting Precise Current Values for DC Margining and

Backlight Control

? Replaces Complex Compensation Circuitry That Stores

Values in Look-up Tables Needed for Precise Resistor

Setting

? Setting Precise Resistance Values for Test and

Measurement Circuits

? Adjust Specific Resistances in Analog Circuits

? Precise Calibration and Fine Tune-Up