ST enhances user experience for portable devices with single-channel touch-sensor IC

GENEVA, SWITZERLAND: STMicroelectronics, a leading developer of semiconductors for mobile and consumer products, has released details of a touch-sensor controller that improves the performance and styling of products such as mobile phones, portable consumer products and appliances.

Consumers will find these products more stylish because the new controller allows replacement of traditional buttons with a touch sensor for main power-on/off control or to trigger wake-up from battery-saving sleep modes.

The success of wireless devices in the home, office and on the road is leading to more and more battery-powered nomadic products that must achieve long battery recharge intervals while also providing powerful functionality such as advanced sensing capabilities that can detect either human touch or proximity. ST's new chip, the STM8T141, helps designers meet both of these demands.

Already in production for a leading cellphone maker, the 8-pin STM8T141 draws a current as low as 11 microamps from the battery and can detect user presence via the touch-sensor electrode, responding quickly to wake the system from a low-power sleep mode.

The chip is designed to monitor a single touch-sensing electrode embedded on the control panel of the end product or in the outer casing. The sensor may be hidden, or its position indicated using a printed, overlaid or illuminated icon.

The new controller also supports proximity sensing, allowing equipment to be controlled without direct contact from the user. This allows the sensor to control power-saving features such as system wake-up on user detection, or features for added convenience such as automatic backlight activation supporting find-in-the-dark capability.

Hence, using the STM8T141 for touch or proximity detection helps product stylists achieve their desired look and feel in a wide variety of product designs.

The STM8T141 features built-in calibration and compensation, which saves time during product manufacture and allows touch sensing to operate reliably for the lifetime of gadgets such as kitchen appliances, universal remote controls, game terminals, home-A/V products, wireless keyboards, personal media players, audio headsets and many other products.

The device also supports a driven electrode-shielding wire, which protects against noise from external sources without the reduction in electrode sensitivity experienced with a grounded shield.