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Digitally controlled potentiometer reduces cost, programming and system calibration

Milpitas, Calif.—Intersil Corp. has introduced ISL22317, a low-voltage digitally controlled potentiometer (DCP) with < 1 percent typical resistor tolerance. The ultra-low tolerance allows the ISL22317 to be used as a true variable resistor, enabling users to set standard and non-standard resistor values for open-loop applications.

The ISL22317 is aimed at designs that require specific current and resistor values 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/°C, improving overall system accuracy for temperatures up to 125°C.

According to Interil, the ISL22317 reduces programming time and development costs by letting users 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 an easy-to-use 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.

Additional features include 128-tap positions; pin selectable slave address; 10k-ohm, 50k-ohm and 100k-ohm total resistance options; monotonic over-temperature; and a single 2.7V to 5.5V supply.

The ISL22317 is available in 3mmx3mm TDFN package—0.75mm max thickness, 0.65mm pitch.

Pricing: 1,000-unit pricing is $1.80.
Availability: Now.
Datasheet: click here.

Intersil Corp. www.intersil.com

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