MICROCHIP ATQT4-XPRO

The QT4 Xplained Pro kit is an extension board for evaluating the self-capacitance proximity and touch functionality of the Peripheral Touch Controller module. The kit demonstrates how to easily design a capacitive touchpad solution for the PTC without any external components. The QT4 Xplained Pro is an extension board designed for Xplained Pro MCU boards featuring microcontrollers with a built-in Peripheral Touch Controller. The extension board can be used to explore the touch functionality of the PTC module in self-capacitance mode and includes touch and proximity sensing capabilities. Two sensors on the extension board provide proximity detection. The first sensor is unshielded, consisting of a single electrode on the top layer of the PCB, with all copper shielding beneath the sensor electrode removed; this sensor responds to touch/proximity from both the top and bottom sides of the PCB. The second proximity sensor uses active or driven shielding and consists of two electrodes — a top-side sensor and a bottom-side shield. The shield is driven by the microcontroller through an external op-amp on the extension board. Active shielding offers two key advantages over the unshielded sensor: first, it suppresses all touch and proximity detection from the bottom (shield side) of the proximity sensor, allowing detection only from the top side (sensor side) of the PCB; second, it moderately increases the detection range of the sensor compared to an unshielded sensor of the same size.

• QTouch Technology
• Two buttons
• Two proximity sensors
• One unshielded sensor
• One driven-shield sensor with external op-amp drive
• LED indicators
• One LED per self-capacitance button
• One LED per proximity sensor
• Op-amp power jumper
• Power current monitoring for driven-shield op-amp
• Xplained Pro hardware identification system(1)