STMicroelectronics Introduces Series of Capacitive Touch Sensors
STMicroelectronics introduced the QST108, the company's first product in its family of capacitive touch sensors, which will enable a stylish, innovative user interface with a wide range of applications. The QST series are all digital standard products, using ST's recently proven patented technology from Quantum Research Group. ST is the first semiconductor company to receive the QProxTM technology license from Quantum Technology.
Touch-sensing controllers are fast becoming the preferred electromechanical switch replacement because designers use these products to create a stylish, affordable, and versatile device for devices that consider durability, ease of use, and price as key considerations. User Interface. With the QST series of products, it is very easy to realize a closed backlight sensing surface, manufacturers can greatly reduce the cost of the touch panel, while also creating a novel and stylish user interface. The QST108 is the first product of ST's QST family of capacitive touch sensors, using a purely digital firmware-based solution that enables the company's proven QProx charge transfer capacitor technology to provide a response to user touch. Single-chip intelligent control interface.
The QST108 allows customers to design 8-key capacitive touchpads for their product's user interface using common or flexible printed circuit boards. The sensing electrodes can be designed in a printed circuit board layout and can even be printed on a circuit board with conductive ink. This method has flexible electrode sizes and shapes. The QST108 can detect the finger touch with electrodes behind the panel made of non-conductive material (glass or plastic). The external component requirements are very low, requiring only one sampling capacitor and one resistor per channel.
The QST chip does not require a production line or user calibration. To ensure maximum availability and control consistency, these products integrate complex drift compensation, auto-calibration, noise filtering and adjacent key suppression algorithms (AKSTM). The configuration of these products allows manufacturers to flexibly design the thickness of the touchpad, which can be designed from very thin plastic sheets to 10mm glass sheets. In addition, the pioneering and patented touchpad construction methods are also beneficial to QST users, which are available to ST customers.
The QST108 touch-sensing controller eliminates the need to develop additional software, allowing different sensing modes to be selected via firmware and optional resistors. By replacing the electromechanical switch with a solid-state switch, QST adds flexibility to the user interface design, providing a stable, reliable capacitive touch solution that allows customers to easily customize QST based on product design, when developing different styles of product design. It is also very easy to reconfigure QST. QST standard solutions dramatically reduce development time and costs, and design engineers can focus their creativity on system design.
The new product is initially available in a 32-pin LQFP package. The QST108 drives up to 8 LEDs. The new product has a built-in PWM (Pulse Width Modulation) controller that can drive a buzzer output or control LED brightness. The debounce touch detection result can be obtained through a single output or an I2C interface.
The QST 108 can communicate with the application host controller via the I2C interface. User-configurable parameters and control functions such as detection thresholds, detection integrators, sensor calibration, low-power mode activation, AKS mode and button status and configuration are available through simple I2C commands.
ST will also expand its QST product line in the future, offering products with different button counts and new features such as capacitive rollers and sliders. ST will introduce 1-, 2-, and 4-key products in this issue, as well as more complex 7-button products with wheels or sliders. ST multi-key products will use QMatrixTM technology from Quantitative.