ON Semi Launches High-Resolution I2C- and SPI-Compatible Digital PotentiometersJune 11, 2009 by Jeff Shepard
ON Semiconductor has further expanded its family of Digitally Programmable Potentiometer (DPP™) ICs with new high-resolution devices incorporating I²C and Serial Peripheral Interface (SPI) Bus connectivity. The new DPPs are said to offer a low-noise, reliable and space-saving alternative to mechanical potentiometers in applications ranging from instrumentation and industrial automation to portable battery-powered equipment.
The CAT5171 and CAT5172 are single-channel, digitally programmable linear taper potentiometers featuring 256-position resolution. Digital control of wiper settings is made via I²C and SPI interfaces, respectively, and both devices are available with end-to-end resistance options of 50 and 100kΩ.
The CAT5171 and CAT5172 are insensitive to mechanical vibrations, shock, oxidation, and dust and dirt unlike their mechanical counterparts. Each device also has a low temperature coefficient of 100 part per million per degrees Celsius (ppm/°C). As a result they are said to be much more stable and reliable than mechanical potentiometers across a wider variety of environmental conditions.
The new DPPs are well suited for volume control, lighting control, LCD screen adjustment and other circuitry requiring electronic control of key parameters. In addition, the parts also offer a flexible solution for RF amplifier biasing and gain control.
Rated for the full industrial temperature range of -40 to 85°C, the ON Semiconductor CAT5171 and CAT5172 operate with a single supply voltage of between 2.7 and 5.5V. In power-up, the wiper assumes a mid-span position and may be repositioned anytime after the power stabilizes. Operating current for both devices is just 2µA.
The CAT5171 and CAT5172 digitally programmable potentiometers are supplied in lead (Pb) free, RoHS-compliant 8-lead SOT-23 packages measuring just 2.9 x 3.0mm. Pricing is $0.60 USD per unit in 10,000 unit quantities. Samples are available now. Projected lead-time for production quantities is currently eight to 12 weeks after receipt of order (ARO).