Single-chip maXTouch touchscreen controller

Microchip has unveiled a family of single-chip maXTouch touchscreen controllers suitable for modern automotive capacitive touch systems with screens up to 20 inches in size.

As touchscreen displays in the car grow larger, drivers expect screens to operate with the same touch experience as mobile phones. However, screens in automobiles need to meet stringent head impact and vibration tests, and consequently have thicker cover lenses that potentially impact the touch interface performance. As screens get larger, they are also more likely to interfere with other frequencies such as AM radio and car access systems.

The MXT2912TD-A has nearly 3,000 touch-sensing nodes, and the MXT2113TD-A, supports more than 2,000 nodes. These devices build upon Microchip’s existing maXTouch touchscreen technology that is widely adopted by manufacturers worldwide. Both solutions offer superior signal-to-noise capability to address the requirements of thick lenses, even supporting multiple finger touches through thick gloves and in the presence of moisture.

The MXT2912TD-A and MXT2113TD-A devices incorporate self- and sensor-diagnostic functions, which constantly monitor the integrity of the touch system. These smart diagnostic features support the Automotive Safety Integrity Level (ASIL) classification index as defined by the ISO 26262 Functional Safety Specification for Passenger Vehicles.

They also feature technology that enables adaptive touch utilising self-capacitance and mutual-capacitance measurements, so all touches are recognised and false-touch detections are avoided.

Both also feature Microchip’s proprietary new signal-shaping technology that significantly lowers emissions to help large touchscreens using maXTouch controllers meet CISPR-25 Level 5 requirements for electromagnetic interference in automobiles. The new touch controllers also meet automotive temperature grade 3 (-40 to +85°C) and grade 2 (-40 to +105°C) operating ranges and are AEC-Q100 qualified.

With the addition of the new maXTouch touchscreen controllers, Microchip is able to provide full scalability, offering, what s claims, is the industry’s only complete and growing portfolio of automotive-qualified touchscreen controllers for the use of various screen sizes.

An evaluation kit is available for each of the parts in the new maXTouch touchscreen controller family. The kit includes a Printed Circuit Board (PCB) with the maXTouch touchscreen controller, a touch sensor on a clear glass lens, the Flat Printed Circuit (FPC) to connect to the sensor display, a converter PCB to connect the kit to the host computer via USB, as well as cables, software and documentation.

All parts are compatible with maXTouch Studio, a full software development environment to support the evaluation of maXTouch touchscreen controllers.

The MXT2912TD-A and MXT2113TD-A devices are available now in sampling and volume quantities in LQFP176 and LQFP144 packages, respectively.