However, these advancements pose significant challenges to the integration of capacitive touch sensing, primarily due to its reduced thickness and the increasing number of touch electrodes. To address these challenges, Microchip Technology has introduced the ATMXT3072M1 and ATMXT2496M1 families of touchscreen controllers to provide automotive human-machine interface (HMI) designers with reliable touch solutions. These single-chip touchscreen controllers, which incorporate up to 112 reconfigurable touch channels, or an equivalent of 162 touch channels in ultrawide mode, support large, curved, and molded touchscreens up to 20 inches in 16:9 format and 34 inches in 7:1 format.
Large, thin displays, such as on-cell OLED displays, incorporate touch electrodes with higher capacitive loads and more intense coupling to screen noise, increasing the risk of false or missed touches. The new devices, part of the maXTouch® family of touch controllers, employ Microchip's Smart Mutual touch acquisition method and algorithms to increase the signal-to-noise ratio (SNR) by up to 15 dB compared to the previous generation.
“The size and appearance of displays in automotive cockpits can greatly influence a buyer’s perception of a vehicle’s technological sophistication. However, integrating reliable touch functionality into advanced displays can present significant challenges,” said Patrick Johnson, corporate vice president overseeing Microchip’s HMI division. “Our ATMXT3072M1 and ATMXT2496M1 touchscreen controllers address these challenges with innovative detection algorithms for fast and reliable touch performance. This enables automakers to design the most advanced, visually stunning, and user-friendly interfaces, enhancing both the driving experience and vehicle safety.”
The ATMXT3072M1 and ATMXT2496M1 controllers are designed to meet ASIL-A and B standards and were developed in accordance with Microchip’s ISO26262 Functional Safety Management System, which is certified by TÜV Rheinland. The FMEDA (Failure Modes, Effects and Diagnostic Analysis) report and safety manuals are also available to customers to help them obtain certification for the touch functionality of their systems more efficiently and cost-effectively. The touch controller firmware is updatable via the vehicle's central computer system and can be verified using the integrated firmware authentication function, which implements the SHA-512 cryptographic function. This cybersecurity feature enables reliable over-the-air (OTA) updates compliant with ISO 21434:2021 standards.
With the aim of limiting driver distraction and promoting safer driving, Euro NCAP testing will likely encourage manufacturers to use separate physical controls for basic functions by 2026. Microchip's Knob-on-Display™ (KoD™) technology allows for the addition of intuitive physical buttons to the touchscreen, improving safety while maintaining the sleek appearance of displays in modern vehicles. Implementing haptic feedback on the touchscreen is a proven method for reducing driver distraction. The new maXTouch M1 Generation touchscreen controller incorporates special features such as Shape Event Trigger, along with automatic PWM (Pulse Width Modulation) for ultra-low-latency haptic control. This innovation transfers decision-making and haptic waveform generation from the main application's host processor to the touchscreen controller.
