CES 2012: Touchscreen controllers set new standards of performance

The performance of the new maXTouch S Series, says Atmel, is achieved by eliminating the impact of system noise, enabling slim sensors and supporting active and passive stylus. According to the mcu specialist, the touchscreen controllers are suitable for the design of intuitive touchscreen interfaces of up to 17in diagonal for products such as smartphones, tablets, digital cameras and e-readers. The series includes the mXT224S, a 224 node controller; mXT336S, a 336 node controller; and mXT1664S a high node density, single chip 32bit solution targeted at tablet products with touchscreens of 10.1in and above. Atmel says a feature of the maXTouch S Series is SlimSensor Technology, which enables system designers to deliver mobile products that are thinner and lighter than was previously possible, without sacrificing immersive responsiveness, touch fidelity or battery life. The technology is a combination of hardware and firmware innovations designed to combat display noise up to 3.5V from any type of display, including ACVCOM lcds and noisier high pixel density displays. SlimSensor Technology features full hardware acceleration of noise cancelling functions and, according to Atmel, delivers industry leading noise immunity with a 2X improvement in responsiveness compared with the current generation of maXTouch devices. The technology does not require additional listening channels, synchronisation to display timing, or tuning and with it, designers can use sensor technologies including fully laminated, unshielded touch on lens sensors, display integrated on cell sensors and ultra thin film sensors. Atmel says the advanced touch sensor stacks are up to 58% slimmer than conventional counterparts. Another maXTouch S Series feature, maXCharger Technology is a blend of analogue circuitry and algorithms designed to enable flawless touch performance with battery chargers that output up to 240V of common mode noise. The technology is said to eliminate false touches while maintaining 'industry leading' responsiveness, linearity and low jitter performance. It utilises high voltage and advanced algorithms to provide the equivalent of 14.4V touch sensor scanning on the mXT336S and the mXT224S, resulting in a 4.5X improvement in SNR in noisy conditions. The mXT1664S provides the equivalent of 24V touch sensor scanning with a corresponding SNR increase, according to Atmel, shattering previous industry records. System designers can choose to engage this high voltage scanning only when the charger is plugged into the system, as it is not needed when the system is running off the battery. maXCharger Technology also utilises spike suppression to remove severe noise spikes before they corrupt measurements and active noise avoidance to seek out quieter operating frequencies. Atmel claims these enhancements result in a 3X increase in responsiveness compared to previous generations of maXTouch devices in the presence of severe charger noise. Atmel says the controllers deliver additional breakthroughs for maximum touchscreen performance: Fully parallelised touch sensor scanning, enabling the industry's fastest report rates; Sensor electrode pitch that is narrower than 4.5mm in common smartphone and tablet screen sizes, for higher touch sensing and stylus tracking resolution that matches increasing display pixel density; and improved touch processing algorithms, for better finger tracking precision, improved accuracy and linearity, and more sophisticated rejection of unintended touches. "The introduction of the maXTouch S Series represents a major milestone for Atmel and a fundamental redefinition of how touchscreen design can be accomplished," said Peter Jones, vice president of the microcontroller and touch business unit, Atmel. "Designers of industry leading touch interface products will no longer have to compromise on touchscreen performance and extreme functionality because of system noise. Freed from previous constraints, design engineers now have a technology platform with which they can unleash their creativity and integrate touch interfaces into a new breed of mobile products that will delight consumers." maXTouch S Series devices are now sampling with lead customers. Production quantities will be available in Q1 2012.