Touchscreen controller supports gloved finger operation on 7 inch displays

October 12, 2012 // By Julien Happich
Atmel has released a series of automotive-qualified maXTouch controllers for in-car control systems, bringing today's smartphone experience into contemporary cars, even for drivers wearing gloves.

The mXT143E and mXT224E touch controllers are designed for small automotive touchscreens and touchpads up to 7 inches in diameter such as center stack displays, navigation systems, radio human-machine interfaces (HMIs) and rear-seat entertainment systems.
By addressing smaller screen and touch-pad sizes, the chips complement the company’s growing family of automotive-qualified touchscreen controllers that support screens/pads from 2 to 12 inches in diameter.
The mXT143E and mXT224E are fully automotive-qualified according to AEC-Q100. Embedded functionalities include high-temperature behavior and reliable operation in harsh environments and with gloved fingers. The high signal-to-noise ratio of 80:1 makes these devices ideal for very noisy environments. The mXT143E and mXT224E embed X/Y position calculation as well as post-processing algorithms such as eliminating unintended touches.

With touchscreens and pads based on these new maXTouch controllers, users can perform multi-touch gestures (pinch, stretch, etc.), while unintended touches, such as a resting hand on the screen, are rejected.
The devices feature true 12-bit touch functionality with independent X/Y tracking for up to 10 concurrent touches in real–time, allowing for the highest linearity and accuracy. Adaptation to high-resolution displays is easy and quick. The user-configurable ratio of X and Y lines supports a variety of aspect ratios from 4:3 to 16:9. Additional maXTouch capabilities targeting automotive applications include frequency hopping during burst generation, self calibration, detect integration addressing EMI/EMC requirements and high reliability in harsh environments. With a scan speed of up to 280Hz, design engineers can provide character recognition for alpha-numeric inputs to the automotive HMI interfaces, another key feature for modern cars.
Samples of automotive-qualified mXT143E and mXT224E touch controllers are available now in TQFP48 packages. Mass production will start the end of October 2012. Demo kits for both devices are also available to support design-in and shorten time to market.

Visit Atmel at www.atmel.com/microsite/maxtouch_eseries_automotive/