KE1xZ robust 5V MCUs put capacitive touch sensing technology at your fingertips.
Touchscreens are so commonplace in our smart, connected world that it's hard to imagine daily life without the intuitive ease and convenience of touch sensing interfaces. Think about all of the devices we control with a simple touch, pinch or swipe: kitchen appliances, refrigerators, thermostats, smartphones, laptops, tablets and other handheld devices, game consoles, automotive infotainment displays, smart home and building controls, point-of-sale terminals, electronic voting machines and a wide range of industrial controls. The list is virtually endless.
The phenomenal popularity of touch-enabled smartphones fueled the rapid growth of the touchscreen market. Capacitive touch technology quickly eclipsed resistive controls, and capacitive is now the dominant touch technology in the smartphone, handheld and consumer electronics markets. And for good reason: resistive touchscreens are notoriously inaccurate, hard to use and often limited to one touch at a time while capacitive touch is much more precise, more affordable and easier to implement, and can support advanced multi-touch and pinch-to-zoom control.
Human machine interface (HMI) is an interactive screen that provides information, data and situation metrics of a system to a human operator. HMI innovation never rests, and now we have advanced gesture and voice controls and even combinations of both technologies, enabling sophisticated touchless user interfaces – a boon for new and emerging products during the touch-adverse COVID-19 pandemic.
Despite the growing popularity of touchless controls among tech enthusiasts, the tried-and-true touchscreen is still one of the easiest to use, most intuitive of all interfaces. Touch sensing remains a proven, go-to HMI technology for myriad applications, making clunky, unreliable electromechanical pushbutton controls a thing of the past. Nowadays, it’s simply touch and go.
With the constant demand for capacitive touch controls in embedded applications, developers are continually seeking faster, easier and more economical ways to add capacitive sense interfaces to their products. NXP has been providing capacitive touch sensing solutions for several years, offering a wide range of 8-bit and 32-bit touch-enabled microcontrollers (MCUs), along with a comprehensive hardware and software ecosystem to simplify touch interface application development. NXP continues to develop touch sense interface (TSI) technology to address new consumer and industrial use cases and demanding application requirements.
NXP has expanded its 32-bit Kinetis E family, part of the EdgeVerse™ edge computing platform, to include the KE1xZ series of robust 5V MCUs offering high performance, broad scalability and advanced touch sensing capabilities. Based on the Arm® Cortex®-M0+ core running at up to 72 MHz, the KE17Z/13Z/12Z MCUs support up to 256 KB flash, 48 KB RAM, and a rich set of analog/digital peripherals. The KE1xZ series extends the Kinetis E family with optional dual-touch TSI technology supporting up to 50 channels, providing a high level of stability and accuracy for HMI applications.
NXP’s KE1xZ touch sensing MCUs provide turnkey solutions for adding sleek, intuitive, touch-based user interfaces to a wide range of products including home appliances, consumer electronics, lighting control, portable devices, medical equipment, point-of-sale equipment, 5V motor control, and industrial instrument and control panels. The KE1xZ MCUs offer advanced noise immunity, water-tolerant touch and low-power wake-on-touch operation, essential features for the strict electromagnetic compatibility (EMC) standards of the industrial and home appliance markets.
Get your hands on NXP’s touch sensing solutions today. Learn more about the FRDM-KE17Z: Freedom Development Platform board to get started.
The 5V KE1xZ MCUs are designed to maintain high reliability and robustness in operating environments subject to harsh electrical noise, making them a good choice for home appliances, industrial and automotive designs. The KE1xZ MCUs include a 12-bit ADC, capable of up to 1 mega-sample per second (Msps), and up to three FlexTimers, making the MCUs an ideal solution for brushless DC (BLDC) motor control systems. Optional MSCAN technology, a communication controller specification implementing the CAN 2.0A/B protocol, allows the MCUs to be used for CAN node control and automotive aftermarket applications.
Today’s multi-burner induction cooktops exemplify an application challenge where NXP’s robust KE1xZ MCUs and versatile touch control technology really shine.
It begins with the KE17Z MCU’s dual TSI technology supporting up to 50 touch channels. In the self-capacitive mode, developers can use these 50 channels to design 50 (25 x 2) touch pads. In the mutual-capacitive mode, design options expand to up to 72 (6 x 6 x 2) pads. In some use cases such as a multi-burner induction cooker with touch controls, the MCUs can support touchscreen designs scaling up to 98 pads (26 pads using self-capacitance + 72 pads using mutual channels). These flexible multi-touch design capabilities enable consumers to easily control multiple induction burners, accurately adjust the heat and cook large family meals on a single induction stovetop.
The KE1xZ MCUs also include three shield channels in each TSI module to enhance liquid tolerance in the presence of water, steam, oil and other spills. NXP’s configurable TSI technology supports adjustable resolution and sensitivity allowing it to perform in challenging environments, even when implemented beneath 12 mm glass or 10 mm glass/plastic overlays, or in industrial control systems requiring high tolerance of harsh conditions.
NXP’s comprehensive hardware and software ecosystem enables developers to quickly evaluate, prototype and create innovative capacitive touch sensing applications. NXP’s Freedom development platforms include low-cost, compatible boards with a rich set of third-party expansion options. NXP’s MCUXpresso software development kit (SDK) also includes a library of touch sense software.
To help developers jumpstart their designs, NXP offers a series of application notes including a BLDC use case, 2D touch solutions, hardware design guideline and software migration guidelines for the FRDM-KE17Z evaluation board, FRDM-TOUCH development platform and FRDM-MC-LVBLDC 3-phase BLDC motor control development platform.
NXP also provides the X-KE17Z-TSI-EVB touch-pattern evaluation board to help developers evaluate and prototype self-capacitive touch keys, mutual cap touchpads, digital touch sliders, proximity loops and shield electrodes.
Learn more about the KE1xZ series of MCUs and how to design your next capacitive touch interface application.
Cristiano joined Philips Semiconductors (now NXP Semiconductors) in 2000 as the applications group leader for camera sensors and image processors for mobile phone applications. From 2005 to 2014, he held several different corporate leadership roles in strategy, technology and new business initiatives. He is now responsible for MCU product innovation in the Edge Processing Business Line.
