Touch IC Cuts Interface Costs

Emerging as the first capacitive touch-slider IC, the QT401 QSlide replaces electromechanical controls by mimicking a potentiometer. The device promotes cost savings and greater reliability over electromechanical alternatives as there are no moving parts to wear out and the control can be fully sealed, making it environmentally impervious. It specifies a 7-bit resolution with position data sent via a standard SPI interface to the host controller. Employing the company’s spread-spectrum modulation, which minimizes emissions and enhances noise immunity, QSlide uses two charge-transfer sensing channels that work across a linear resistive element. The resistive element can be discrete resistors connected in series, a resistive thick-film layer, or an optically clear, indium-tin-oxide film for use over LCDs. Finally, a mathematical technique is used to determine the touch position, independent of signal strength. Price is $1.97 each/100,000 and an evaluation board (E401) is available for $95. For more details, contact George East at QUANTUM RESEARCH GROUP LTD., Southampton, UK. +44 (0) 2380 565600.