IC provides all of the functions needed to create a fully functional touch interface for a mobile phone or other handheld device. The AT42QT1060 is a touch sensor IC designed to make the development of mobile and other applications as fast and simple as possible.
It is based on Atmel's QTouch™ technology and provides all of the signal processing and input/output functions required in a tiny 28-pin, 4 mm x 4 mm RoHS compliant package. AT42QT1060 includes a guard channel to prevent false detections by other keys, and features LEDs directly powered by the IC, eliminating the need for an external LED controller.
The EVK1060A allows the user to evaluate all functions of the AT42QT1060 touch sense controller. The kit provides a convenient reference design and allows the user to visualize discrete touch buttons, the guard channel and LED control.
The EVK1060A works stand-alone but can also be connected to a host or a PC. The device comes fully assembled, tested and documented.
Dynamic Programming by Host
Configuration and adjustment of the operating parameters is carried out by the host processor via the I²C compatible interface. This can be done dynamically if necessary – the interface can respond instantly to changing conditions.
Low Component Count, Easy Circuit Design
Each sensor channel used requires only two external components. An operational circuit can be built on a few square centimeters of PCB.
Multiple Interface Opportunities
input output six touch sensor channels provide dozens of possibilities for inventive user interface designs. In the example diagram, five discrete touchkeys are used to provide a joystick quadrant, with a selection touch pad in the centre. The sixth channel is used to provide a guard band channel which will prevent false detections on the other keys when the device is in a pocket or held to the user’s ear.
Designing a hand held device with touch sensors that resist false detections can be challenging. The capacitance changes that indicate the user's touch inputs can also be produced by normal handling. The device must have a reliable way of distinguishing between the two. The AT42QT1060 achieves this by using Quantum’s patented Adjacent Key Suppression™ (AKS™) technology and the ability to adjust individual key sensitivity to provide a guard channel feature. The guard channel is connected to an additional sensor region surrounding the entire sensor key region. AKS is used to prevent other keys from operating when the guard channel key is touched. This means that only intentional key presses will be accepted. All touches that include the guard channel (if the user holds the device to their ear, for example) will be ignored. Guard channel operation combined with Quantum’s inherently reliable spread spectrum detection technology provides a very rich user interface that effectively eliminates false detections – no matter how roughly the device product is handled.