Date: 26/06/2009

Low voltage digital controlled potentiometer with 1% resistance tolerance

Intersil launched low-voltage, precision, digital potentiometer ISL22317 with less than 1% resistance tolerance, and zero-compensated wiper resistance. Intersil claims this device is more than 200 times accurate than other in the market.

All these features make ISL22317 an ideal digitally controlled replacement for true wiper type mechanical variable resistor/potentiometer, allowing users to set standard and non-standard resistor values for open-loop applications.

The ISL22317 is a right choice for applications such as test and measurement circuits, medical devices, backlight controls, or adjusting specific resistances in analog circuits. The patent-pending architecture of the ISL22317 allows it to track an external resistor within 10ppm/ Deg C, improving overall system accuracy for temperatures up to 125 Deg C.

The ISL22317 allows the users to select accurate pre-determined resistor values, and use calculated resistor values in schematics. In addition, it allows one to use the known value of one system to calibrate other systems. The device employs I2C interface to program accurate resistor settings >1 million times in the integrated EEPROM memory.

The ISL22317 also features a zero-compensated wiper resistance in rheostat mode. By negating wiper resistance, overall accuracy is improved, especially at the low tap positions where the ratio of wiper resistance to actual resistance is much higher. This enables users to do schematic calculations based on an actual 1 percent value, instead of competitive solutions that have >±20 percent tolerance of the resistor string in addition to wiper resistance error.

The other specifications/features of this device are:

128-Tap Positions
I2C Serial Interface
Pin Selectable Slave Address
10k-ohm, 50k-ohm and 100k-ohm total resistance options
Monotonic over-temperature
Non-volatile EEPROM storage of wiper position
Single 2.7V to 5.5V supply
-40oC to 125oC operating temperature range

Packaging, Pricing, and Availability The ISL22317 is available in 3mmx3mm TDFN Package - 0.75mm max thickness, 0.65mm pitch. Versions with 10k-ohms, 50k-ohms, and 100k-ohms are available; 1,000-unit pricing is $1.80.