Touch IC - Integrated Circuit
Touch controller IC is a circuit that converts input signal (a finger or an object that comes in contact with screen’s surface) into a measurable signal which is calculated and processed by controller software algorithms to determine touch position on the screen.
A touchscreen controller IC is created with dedicated peripherals pins to enable interfacing with touch sensors and host processor. Commonly, this circuit is mounted on FPC (flexible Print Circuit) which connects sensor to the host processor.
What does a Touch IC do?
Regardless of touch technologies, whether it is resistive or capacitive touch sensor, when a finger or stylus comes in contact with surface of the touchscreen, the IC tracks and reports the location where the touch was sensed. For example, using a typical capacitive touchscreen, the IC controller measures the capacitive changes at the intersection between the X and Y lines and compares against sensitivity threshold configuration given by the firmware in order to determine actual touch.
Some controller IC designs use a combination of self-and mutual-capacitance measurements to achieve high accuracy of single-and multi-touch within an application. With help of optimisable software, systems can perform self-capacitance touch scan during idle operation or single point tracking. When more than one touch has been detected, the device triggers mutual-capacitance touch scan. This approach gives great advantages to application design such as power efficiency, touch accuracy and noise immunity.
Why should you choose the correct touch IC?
Knowing your application requirements key to determining the correct type of touch controller IC for your application. To ensure your application meets user expectations, the touch IC not only needs be able to respond to the finger touch and/or complex gestures but also needs to perform correctly under critical environment conditions such as high/low temperature, steam or wet conditions, thicker, vandalproof glass. Therefore, when selecting a touch IC for your application the following elements should be taken in consideration:
- Performance requirements