The TouchNetix aXiom Capacitive Touchscreen IC has been designed to address the shortcomings of the re-purposed consumer electronics touchcreen IC's currently available in the market. The chip is designed specifically to address the needs of industrial and automotive end user applications and to bring together the broad range of requirements which have emerged over the past few years.
The chip has greater than 80dB SNR (compared to typical 50-60dB for other chips on the market, allowing it to work flawlessly in applications where other ICs struggle to cope with the electrical noise in challenging industrial and automotive environments. It achieves this while maintaining a low 2.5V pk-pk neutral drive which is ultra-narrow band and sinusoidal in nature and so the emissions are compliant with CISPR25 Level 3 without implementing expensive counter-measures. Because of the neutral drive, the sensor materials are less stressed from high field strengths leading to longer lifetimes and less premature touchscreen failures.
The high SNR of the chip means that sensor designs become much less critical, allowing a broader range of suppliers to be used saving cost and improving time-to-market. A broader range of materials stack ups are possible with up to 10mm of acrylic and even air gaps in the structure being possible. The sensitivity is also configurable on a node-by-node basis allowing the use of variable thickness overlays on the screen allowing structures to guide the users finger to be developed with ease.
Proximity measurements of an approaching finger of more than 10cm are possible and greater than 6cm of 'hovering' finger position can be detected with ease.
The IC also supports force sensing measurements and drives haptic feedback, allowing sophisticated user interfaces to be developed. The haptic feedback can be defined within the IC according to various zones with different effects; these effects are driven autonomously without involvement from the host, allowing for sub-20mS system latency.
The aXiom IC provides a holistic approach to the emerging requirements of the automotive and industrial OEM's, simplifying the job of the industrial designer and providing peace of mind from a manufacturing and reliability point of view.