Touchscreen Controller ICs by TouchNetix
Optimised for Industrial and Automotive Applications
Fortsetzung des Artikels von Teil 1
High signal-to-noise ratio
This high SNR is enabled with TouchNetix’ aXiom controller while driving the sensor at a low DC-neutral 2.5Vpk-pk, whereas other controllers, according to TouchNetix, often use a drive voltage of +30V or higher to achieve even a modest SNR. The aXiom IC’s low drive voltage produces very low levels of radiated emissions. The DC neutral bias also reduces the stresses experienced by the touchscreen materials. High drive voltages can result in in optical damage and even metal migration – a form of galvanic corrosion – in the sensor material leading to premature failure of the touchscreen sensor stack.
The aXiom IC’s high SNR also enables reliable multi-point touch sensing through thick overlays, including acrylic thicker than 10mm or with an air gap in the stack, and even when the user wears gloves. Touch response to wet fingers, or when the screen is wet, is also superior to that of existing touchscreen controllers.
The chip’s powerful DSP engine enables micro-adjustment of the sensitivity at each node in the sensor matrix: the screen’s touch-sensing behaviour can be tuned regionally to provide uniform responsiveness to touch across a screen with an overlay of variable thickness. This allows OEMs to rethink the display user interface (UI), building in contours, ridges or valleys to guide the user’s finger while the user looks away from the screen.
The aXiom controller can also perform capacitive proximity sensing at a distance of up to 10cm, and coarse position sensing of a finger as much as 6cm distant from the screen. This supports new hover and proximity functions in touchscreen UIs. In addition, the AX310 integrates concurrent force sensing and haptics control, to allow the touchscreen to guide the user’s finger through space to their chosen button, touch it, and only register a button press when force is detected at the button’s location. The AX310’s high-performance force-sensing measurement engine detects displacement of as little as 5µm.
Chris Ard, managing director of TouchNetix, said: “In the industrial, aerospace, medical and automotive markets, performance, reliability and long operating lifetime are crucial differentiators, but today’s consumer-grade touchscreen controllers are not built to meet these industries’ needs. This makes the market ripe for disruption led by technical innovation, and that’s what TouchNetix is providing with the aXiom touchscreen controllers. In every industry sector, the aXiom series of controllers can enable OEMs to revolutionise the display UI, bringing additional value and functionality, and making the touchscreen a key focus in end products such as cars and home appliances.”
The aXiom controller ICs support touchscreens with up to 56x56 sensing channels, and touch and force-sensing sampling rates of more than 200Hz. They are suitable for use with displays bigger than 15.6” diagonal, and in non-standard form factors and arbitrary aspect ratios. TouchHub development software is provided with the aXiom controllers to ease the design and tuning of touchscreen designs.
The AX310 will be available for sampling in Q1/2019 and will be AEC-Q100 Grade 2 qualified by Q4/2019.
- Optimised for Industrial and Automotive Applications
- High signal-to-noise ratio
