Microchip introduces a new capacitive touch controller that accelerates EMI certification for automotive touch screens

     To address the electromagnetic interference (EMI) and electromagnetic compatibility (EMC) issues facing automotive touchscreen developers, Microchip Technology has introduced three new maXTouch touchscreen controllers and additional optimization services. The new TD series touch controllers feature a new differential interactive signal acquisition technology that significantly improves the signal-to-noise ratio (SNR) of the touch screen, works even when covered in thick glass or plastic, and supports multi-touch operation with gloves on the driver, supporting polymethyl methacrylate (PMMA) materials up to 4.5 mm thick.

     For 9 - to 13-inch automotive touch screens, Microchip has introduced several low-cost models based on the MXT1067TD, MXT1189TD, and MXT1665TD. Together with the recently introduced MXT449TD, MXT641TD, MXT2113TD, and MXT2912TD that support 20-inch touchscreens, they comprise Microchip's touchscreen controller line. Each of Microchip's products is designed with customers' growing functional safety needs in mind, while being designed according to automotive SPICE Level 3 capabilities and ISO 26262 Automotive Safety Integrity Level (ASIL)B requirements.

     The TD series has a unique waveform shaping function that optimizes the electromagnetic radiation performance of the touch controller with the EMI optimization tool. Backed by product experts from Microchip's Global Application Design Center, the tool helps developers enter user-defined RF limits and adjust the shape of the transmitted pulse waveforms for touch sensing acquisition.

     Waveform shaping can be achieved through firmware parameters exported by the tool to help designers locate the basic pulse frequency in order to coordinate with other on-board applications, such as remote keyless access control systems. The resulting parameters are then added to the maXTouch profile, which will design customized touch controller parameters for the user. These processes achieve the desired EMI/EMC performance while reducing the need for experimentation to set up different configurations, saving designers hours or even weeks of valuable EMC testing time.

     Fanie Duvenhage, Microchip's vice president of human interface, said: "Our products greatly simplify the design method and shorten the design time of automotive touch screens, helping developers to enjoy the same design environment and product functionality in different models with different sizes, different use cases, different materials and coverage thicknesses." "Microchip's products are supported by eight specialized application and sensor design centers around the world and can assist customers with a variety of configurations on a case-by-case basis, such as screen size and aspect ratio, display type and vendor, and complete stacked architecture."