Multitouch Chip For Mobile Handles Up To 16 Touches

Feb. 11, 2011

Atmel's maxTouch E Series is built on an AVR32 core and handles up to 16 touches on a 12-in screen. Om-chip processing handles touch recognition for a host processor.

William G. Wong

1 of Enlarge image

Atmel mXT768E block diagram

Atmel's popular maxTouch line has received a boost with the latest maxTouch E Family. Leading the pack is the mXT768E (Fig. 1). It supports up to 768 channels and is designed for displays up to 12-in.

The maxTouch E Series is designed to deliver unlimited touch capability while putting the intelligence in the chipset. The multitouch support is configured to handle up to 16 simultaneous touches. This offloads the host processor that is typically running an operating system like Android. The chips have an internal 11-bit precision designed to deliver an 80:1 SNR in mobile applictions. They have a 150Hz response rate.

The new chips employ a split touch engine and microprocessor core. The Atmel AVR32 was tapped for the high end chipset. The other chips in the series that utilize the AVR32 core are the mXT540E and mXT384W. They are designed for smaller displays.

This chips address capacitive touch noise avoidance by automatically changing scanning frequency. Noise suppression is used with the best frequency. The chips can detect a stylus with a tip as small as 2mm. The on-chip processing also can also ignore palms and hand holding issues common with tablets.

The new series also includes the mXT224E, an enhanced version that is pin compatible with an earlier maxTouch chip. It supports 224 channels/nodes and targets displays up to 7-in. The compute engine is an 8-bit XMega core but still delivers a 250Hz update rate. It also support narrow stylus tracking and grip suppression.

Atmel

About the Author

William G. Wong | Senior Content Director - Electronic Design and Microwaves & RF

I am Editor of Electronic Design focusing on embedded, software, and systems. As Senior Content Director, I also manage Microwaves & RF and I work with a great team of editors to provide engineers, programmers, developers and technical managers with interesting and useful articles and videos on a regular basis. Check out our free newsletters to see the latest content.

You can send press releases for new products for possible coverage on the website. I am also interested in receiving contributed articles for publishing on our website. Use our template and send to me along with a signed release form.

Check out my blog, AltEmbedded on Electronic Design, as well as his latest articles on this site that are listed below.

You can visit my social media via these links:

I earned a Bachelor of Electrical Engineering at the Georgia Institute of Technology and a Masters in Computer Science from Rutgers University. I still do a bit of programming using everything from C and C++ to Rust and Ada/SPARK. I do a bit of PHP programming for Drupal websites. I have posted a few Drupal modules.

I still get a hand on software and electronic hardware. Some of this can be found on our Kit Close-Up video series. You can also see me on many of our TechXchange Talk videos. I am interested in a range of projects from robotics to artificial intelligence.