| Using differential mutual signal acquisition method with improved SNR
| Multi-finger touch possible even with 4.5mm thick gloves
| Meets A-SPICE Level 3, ISO 26262 ASIL B

To address the electromagnetic interference (EMI) and electromagnetic compatibility (EMC) issues faced by automotive touchscreen developers, Microchip has released three touchscreen controllers and an optimization service.

Microchip announced on the 1st that it has released three types of 'maXTouch' touchscreen controllers and optimization services.

The latest TD family of touch controllers uses a new differential cross-signal acquisition method that improves the signal-to-noise ratio (SNR).

This supports multi-finger touch when using thick glass and plastic cover lenses and when wearing thick gloves made of polymethyl methacrylate (PMMA) material up to 4.5 mm thick.

The MXT1067TD, MXT1189TD, and MXT1665TD devices are cost-optimized variants for 9- to 13-inch automotive touchscreens, supporting touchscreens up to 20 inches.adds to Microchip’s product portfolio with the MXT449TD, MXT641TD, MXT2113TD and MXT2912TD devices.

Each device meets the increasing demands for functional safety and is designed to meet Automotive SPICE (A-SPICE) Level 3 and Automotive Safety Integrity Level (ASIL) B requirements defined in the ISO 26262 automotive functional safety standard.

All devices in the TD family feature unique waveform shaping capabilities to optimize the radiated emissions (RE) performance of the touch controller via EMI optimization tools.

Developers can collaborate with product experts in Microchip's worldwide application design centers and use the tool to enter user-defined RF limits and adjust the shape of the transmitted burst waveform used for touch detection acquisition.

Waveform shaping is accomplished via firmware parameters derived from the tool, allowing developers to set the default burst frequency to work with other in-vehicle applications, such as remote keyless entry locks.

The configured parameters are simply added to the MaxTouch configuration file, which optimizes the performance of the touch controller to individual customer designs.

This process enables developers to eliminate hours, or even weeks, of expensive EMC test chamber time by eliminating the need to experiment with multiple configurations to achieve desired EMI/EMC performance.

The primary target applications for Microchip's automotive touchscreen controllers are Center Stack Displays (CSDs) and navigation systems, but also include automated It is also ideal for industrial applications such as manufacturing facilities.

The MaxTouch family of touchscreen controllers have evaluation kits available for each component.

Kit numbers are ATEVK-MXT1067TDAT-A(I2C), ATEVK-MXT1189TDAT-A(I2C), ATEVK-MXT1189TDAT-C(SPI), ATEVK-MXT1665TDAT-A(I2C), ATEVK-MXT1665TDAT-C(SPI).

Each kit includes a PCB with a MaxTouch touchscreen controller, a touch sensor with a clear glass lens, a Flat Printed Circuit (FPC) for connecting the sensor, a bridge PCB to connect the kit to a host computer via USB, cables, software, and documentation.

All components are also compatible with maXTouch Studio, a software development environment that supports the evaluation of maXTouch touchscreen controllers.

The MaxTouch EMI optimization service will be available as part of the system support provided by Microchip’s worldwide application design centers.

The MXT1067TD, MXT1189TD, and MXT1665TD devices are available for sampling and volume production now in TQFP128 (MXT1067TD device only) and LQFP144 packages.

Vice President of Microchip's Human Machine Interface Business Unit, Pat“Microchip’s automotive touchscreen solution simplifies and accelerates the design process,” said Fanie Duvenhage. “Developers will be able to use the same design environment and product functionality across vehicle models, a variety of sizes, use cases, cover lens materials and thicknesses.”

“With Microchip’s devices supported by eight application and sensor design centers located around the world,” he said, “customers can design for every requirement – from screen size and aspect ratio to display type and provider, to the architecture of the entire stack.”