With the advancement of human-machine interface (HMI) technology, there is an increasing demand for capacitive touch sensors that can achieve superior design and high operability, adding more value to products. Previously used mainly in high-end home appliances, capacitive touch sensors are now used in low-end home appliances, industrial equipment, building automation control panels, and even in medical and healthcare equipment where the level of hygiene is important. With this diversification of applications, the HMI systems are required to have high performance and functionality.
To meet these needs, Renesas launched the new RX261/RX260 32-bit MCUs with the latest generation capacitive touch sensor IP, CTSU2SL, providing outstanding power efficiency, advanced touch functions, and robust security functions for businesses to release more energy-efficient and versatile applications to the market than ever before.
Outstanding Power Efficiency
The RXv3 core, operating at up to 64MHz, delivers outstanding power efficiency, achieving 355CoreMark. This CoreMark score is 2.5 times higher than a Cortex®-M0+ running at 64MHz and comparable to a Cortex-M4 running at 100MHz. Also, the standby current is kept to a leading-class of 1μA, and power consumption during intermittent operation is minimized with a snooze mode that allows some peripheral functions to operate during standby mode.
Advanced Touch Functions
Compared to previous generations, the CTSU2SL offers improved noise immunity, water resistance, and lower power consumption. The following features enable the introduction of capacitive touch sensors into applications such as kitchen appliances, toilets, and other environments where water and oil stains are likely to adhere, as well as battery-powered and environment-conscious products such as smart locks and small home appliances. Product differentiation can be achieved by implementing advanced touch functionality in more applications.
- Multi-Frequency Scanning: Generates three capacitance measurement clocks to reduce the effects of synchronized disturbance noise.
- Active Shield: Touch electrode and shield guard electrode are driven at the same potential and phase to suppress the effects of water and oil adhesion.
- Automatic Judgement: Detects touch events during standby without the need for a CPU.
- Multiple Electrode Connection (MEC): Reduces touch event measurement time and current consumption by measuring multiple touch electrodes as a single electrode.
Robust Security Functions
The area protection function allows users to set a non-rewritable area in the built-in code flash memory to deter the rewriting of important programs which are the starting point of system security, such as secure boot. The RX261 is also equipped with the latest security IP (RSIP-E11A) and supports management functions to prevent unauthorized use of AES, ECC, and SHA engines and key leakage.
These security features protect user data of IoT home appliances and enable secure update firmware via a wireless network. Furthermore, the 5V operation delivers high noise immunity, and low standby current that complies with energy regulations required for home appliances.
The operation panel using proximity buttons based on capacitive touch sensors allows operation without direct contact and can maintain cleanliness even for equipment used by a large number of people, such as elevators. The operation panel and other modules can be connected via highly reliable CAN FD or CAN.
The capacitive touch sensors provide water and dust resistance for outdoor use, and the smart wake-up solution can be utilized to reduce power consumption and extend battery life. The built-in security features protect passwords and prevent unlocking by unauthorized access, making it ideal for applications like smart locks.
Three types of evaluation boards with RX261 are available for each development phase.
The FPB-RX261 is ideal for initial evaluation, while the EK-RX261 is suitable for evaluating all functions. Lastly, the Capacitive Touch Evaluation System for RX261 is designed especially for capacitive touch solution development.
Please visit the RX261 and RX260 product pages for more detailed information.