Microchip offers safety-certified touchscreen controller for home appliances

To reduce the risk of home fires or floods, European IEC 60730 and U.S. UL 60730 Class B specifications require safety mechanisms in domestic appliances, such as ovens, cooktops, washing machines, and clothes dryers.

Helping designers meet these functional safety requirements in touchscreen enabled appliances, Microchip Technology Inc. announced its maXTouch MXT336UD-MAUHA1 capacitive touchscreen controller family — the market’s only touchscreen controllers to offer pre-certified, Class B firmware.

The family includes three controllers: the MXT112UD-MAUHA1, the MXT228UD-MAUHA1, and the MXT336UD-MAUHA1. Each one offers a different screen size, ranging from 2 to 8 inches.

The Class B certified controllers that offer unique safety features, enabling system shutoff 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 continues 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, VP 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.”

Also, this new family 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.