Microchip Releases Industry's Most Versatile maXTouch Touchscreen Controller

As the automotive market continues to demand large touchscreens and flexible form factors, Microchip Technology Inc. has announced a new maXTouch touchscreen controller that enables automotive developers to meet the unique aspect ratio requirements of in-vehicle touchscreen displays. This new product includes additional functional safety support required by OEMs

The MXT1296M1T can be reconfigured to drive and receive touch channels to match exact screen formats, from 1:1 to 5:1 aspect ratios, including the mainstream 8:3 automotive aspect ratio. This feature enables customers to efficiently utilize the number of touch channels they already have without having to choose a larger, more expensive touch controller. Additionally, customers can save additional development and verification time and resources by reusing a common PCB design to support different touch sensor aspect ratios. The MXT1296M1T is the industry's first product to enable sensor channel reconfiguration via parameters. These settings do not require firmware modifications, reducing design risk and speeding time-to-market.

Clayton Pillion, director of Microchip's Human Interface Business Unit, said: "As touchscreen displays become commonplace in automotive user interfaces, automakers are using a variety of display formats and form factors to accommodate interior designs and enhance their brand image. As a leading supplier of automotive touchscreen controllers, we know a product with enhanced diagnostics is a major advantage for customers who are designing with unique features and the ever-increasing ISO 26262 functional safety requirements in mind.”

Microchip's new maXTouch touchscreen controller provides two simultaneous communication interfaces for bridgeless connection to the back-end channel of the LVDS video link for touch information and to a local microcontroller (MCU). The bridgeless topology reduces touch latency for an improved user experience. It also supports full compatibility with maXTouch software drivers for all major automotive operating systems including Linux, Android and QNX. When connected to a suitable local MCU, the second interface provides:

- Redundant link to head unit via CAN bus or 10BASE-T1S automotive Ethernet for improved system level functional safety

- Local access and control of maXTouch touchscreen controller functions such as capacitive key reporting, real-time touch sensor diagnostics, and raw data for external and custom post-processing.

- Over-the-air and secure firmware update capability using Microchip's TrustAnchor100 companion chip

The MXT1296M1T embeds various functional safety features to continuously check the integrity of the touch controller operation as well as the connected touch sensor. Failure Mode Effects and Diagnostic Analysis (FMEDA) and Functional Safety Manual greatly simplify the customer experience in designing, building and certifying systems for ISO 26262 compliant Automotive Safety Integrity Level B (ASIL-B) applications.

The MXT1296M1T enables high-resolution transmit waveform control to reduce RF emissions and avoid interference with car radios or RFID systems. As car screen sizes increase, RF emissions from capacitive touch technology are expected to increase as well. The radiation limits of the major automakers vary in amplitude, frequency, and bandwidth. The MXT1296M1T uses a dedicated on-chip 64-level digital-to-analog converter (DAC) to precisely shape the waveform of the transmit line. This enables designers to precisely control the frequency response, optimizing harmonic emissions to meet specific OEM-specified constraints.