Microchip has extended its capacitive maXTouch touchscreen controller family with MXT448UD-HA and MXT640UD-HA controllers for harsh and noisy environments where electromagnetic interference can be caused by conveyer belts, power rails, or assembly machinery. These new controllers extend the Class B portfolio of devices beyond 10 inches and provide dedicated solutions for larger screen sizes as well as scalability to customers.
The MXT448UD-HA and MXT640UD-HA controllers are also compliant with the IEC61000-4-6 Class A specification for conducted noise immunity up to 10 Vrms (level three for industrial use). This feature helps manufacturers in increasing production yield. These new touchscreen controllers also come with two serial interfaces (SPI and I²C) that operate simultaneously allowing redundancy in a design through the integration of safety features, such as individual communication between the touchscreen controllers to the host microprocessor (MPU) in addition to a safety microcontroller (MCU).
The unique architecture of the controllers shortens time to market and reduces development cost by allowing all safety-critical firmware to be developed on a dedicated safety-certified MCU (with mandatory source code review by an IEC/UL test lab) separate from the main processor running the appliance’s Graphical User Interface (GUI). In addition to the IEC compliances, these devices support an operating temperature up to 105°C, which is a key requirement for cooktops and ovens where the Human Machine Interface (HMI) system is near heating elements. The two new devices (ATMXT448UD-CCUHA1, ATMXT640UD-CCUHA1) for home appliances are available in volume production starting at $2.40 for the ATMXT448UD part in 10,000-unit quantities.