Automotive touch controllers reduce board space by 75%

By Gina Roos, editor-in-chief

Microchip Technology Inc. has expanded its maXTouch portfolio with the release of its smallest automotive touch controller aimed at secondary displays with advanced features. The new MXT288UD touch controller family, claimed as the industry’s smallest automotive-grade packaged touchscreen controllers, can fit secondary touch surfaces that are found in both the interior of cars and exterior of a motor vehicle, such as handlebars, doors, electronic mirrors, control knobs, the steering wheel, between seats, and in an armrest.

The MXT288UD-AM and the MXT144UD-AM devices, housed in a 7 × 7-mm automotive-grade VQFN56 package, can reduce board space by 75% while minimizing the bill of materials, according to Microchip. The touch controllers feature a low-power wait-for-touch mode that consumes less than 50 µA while remaining responsive for the user even if the display switches off to save power or to avoid disturbing the driver at night. The system will wake by a touch event anywhere on the touch surface.

In addition, the devices offer weatherproof operation and glove-touch detection in multi-function displays, touch pads, and smart surfaces in vehicles, motorcycles, e-bikes, and car-sharing services. This includes detection and tracking of multi-finger thick gloves through a variety of overlay materials and thicknesses, like leather or wood, or across uneven surfaces. This includes in the presence of moisture, including snow, rain, or extreme heat.

These devices provide a unique solution to reliably detect and track multiple fingers with a high signal-to-noise ratio (SNR) and through a proprietary differential mutual acquisition scheme, said Microchip.

The MXT288UD family provides firmware, developed according to Automotive SPICE processes, and is AEC-Q100−qualified — making it easy to integrate into existing systems for a faster time to market. Software tools include maXTouch Studio and maXTouch analyzer.

For the MXT288UD, the hardware includes an evaluation kit with a printed circuit board (PCB) and a 5-in. capacitive touch panel, while the MXT144UD’s evaluation kit includes a PCB and a 2.9-in. capacitive touch pad. For both devices, a bridge PCB is included with a USB connection for interfacing to a computer when running maXTouch Studio.