European IEC 60730 and U.S. UL 60730 Class B specifications require safety mechanisms in home appliances, such as ovens, cooktops, washing machines and clothes dryers.
The family includes three controllers, the MXT112UD-MAUHA1, the MXT228UD-MAUHA1 and the MXT336UD-MAUHA1, each fulfilling different screen size needs, ranging from 2-to 8-inches.
The Class B certified touch controllers offer safety-related features that enable system shut off through an intuitive soft button on a touchscreen, removing the requirement for an external safety certified stop or cancel button and associated microcontroller (MCU). They also allow an appliance to detect a touchscreen or appliance failure and shut down automatically through a variety of self-testing capabilities. For example, if the glass breaks on a cooktop, the touchscreen will turn dark and shut off the machine, eliminating accidental damage in the home.
As the number of touch enabled home appliances continue to increase, the MXT336UD-MAUHA1 family shifts the required safety functionality to a simplified single touchscreen interface, helping OEMs reduce costs and improve time to market.
“Due to the risk of house fires caused by home appliances, appliance manufacturers must add functional safety to their machines, and Microchip’s MXT336UD-MAUHA1 touchscreen controller family is already certified for these required safety standards,” said Fanie Duvenhage, vice president of Microchip’s human machine interface business unit. “Integrating Class B certification into our touch controllers eases the design and qualification process for touch enabled appliances, ultimately putting safety first, while reducing costs and enabling modern user interface solutions.”
The family of devices also leverages a high signal to noise ratio (SNR) design and proprietary differential mutual acquisition scheme. This allows the machine to reliably detect and track multiple fingers on surfaces exposed to moisture, water, grease and more, even if the user is wearing gloves.
