austriamicro digital pot eyes TV receivers, audio systems

austriamicrosystems AG has unveiled its AS1500 family of digital potentiometers that is designed for use in applications where a resistor value must be changed automatically by a microprocessor.

According to austriamicro, the AS1500 family is suitable for volume controls in TV receivers and audio systems, and applications that require line impedance matching, programmable filters or power supply adjustment. The devices can also be designed in, as a replacement solution for mechanical potentiometers.

"The AS1500 family offers several advantages over analog potentiometers," said Walter Moshammer, marketing director for the company's communications business. "These include better resolution, since the AS1500 family has 256 programmable steps, and small form factor as the AS1500 is offered in 5-by-4mm SO-8 packaging."

Moshammer added that the AS1500 functions are also not affected by mechanical disturbances such as vibrations and shocks and are immune from mechanical abrasion, while offering low noise, low temperature drift and high-speed adjustment.

The values of the resistor can be controlled via a 3-wire serial peripheral interface (SPI)-compatible serial data input interface, capable of handling programming rates up to 10MHz. In addition, the AS1500 family is available in four different resistor values.

The AS1500 incorporates a 10 kiloohm, the AS1501 a 20 kiloohm, the a AS1502 50 kiloohm, and the AS1503 a 100 kiloohm fixed resistor. The wiper contact taps the fixed resistor at points determined by an 8-bit digital code word, and the resistance between the wiper and the endpoint of the resistor is linear. The switching action ensures that no glitches occur.

Operating over the extended industrial temperature range of -40°C to 125°C, the new product family includes a shutdown mode, where it consumes <5?A. It is priced at about $1.10 in a thousand unit volume range, and is pin-compatible with the AD8400.