Atmel automotive-qualified touch controllers
July 17, 2013 by John Day
Enabling single-layer shieldless touchscreen and touchpad designs in car center stacks
Atmel® Corporation announced a new maXTouch® family to enable single-layer shieldless designs in automotive center stacks, navigation systems, radio interfaces or rear seat entertainment systems.
Atmel’s mXT336S is optimized for 7-inch touchscreens, while the mXT224S targets smaller touchscreens and touchpads. Both are AEC-Q100-compliant and fully automotive qualified.
They are said to offer superior performance, multitouch, faster response time, more precise touches, robust operation and lower power consumption. The new mXT336S and mXT224S devices also provide dedicated embedded functionality that meet current automotive design requirements.
Dedicated firmware and a high signal-to-noise ratio makes these devices suitable for very noisy environments. Since only a high signal-to-noise ratio enables detection of touches with a “gloved” finger, the devices provide full support for gloved hand operation on automotive touchscreens.
Support for shieldless sensors
One key requirement for automotive designs is the support for shieldless sensors. “Conventional touch controllers are unable to handle LCD noise, so an additional shield layer is required to prevent noise coupling,” said Stephan Thaler, Atmel Marketing Director for Automotive Touch Products.
“Thanks to the superior noise handling and filtering capabilities of our new automotive-qualified maXTouch devices, shields are no longer required, and designers can use single-layer sensors instead of dual or triple layers, which are typical in many current applications.
“By eliminating an additional layer, designers have a thinner stack which reduces the overall system complexity, lowering the overall cost and power consumption, and resulting in higher product yields during production.”
Further embedded automotive functionalities
The mXT336S/mXT224S devices support touch detection, up to 10 simultaneous touches, touch size reporting, single- and dual-touch gesture calculation, communication of X/Y positions, gesture support, and the ability to eliminate unintended touches. Users can perform multi-touch gestures (pinch, stretch, etc.), while unintended touches are rejected, such as a resting hand on the screen. All these key features bring the smartphone experience into contemporary cars.
Samples of the automotive-qualified mXT336S and mXT224S touch controllers are available now in TQFP64 packages. Demo kits for both devices are also available to support design-in and shorten time–to-market.