Renesas Electronics, a provider of advanced semiconductor solutions, is expanding the use of touch key in healthcare, building automation and home appliance applications with the new RX113 Group of microcontrollers (MCUs). Part of the RX100 Series, the new MCUs offer a single-chip solution with touch sensor IP and low-power technologies. This enables significantly reduced power, size, and development costs for entry-level devices in these markets, as well as for other cost-sensitive, capacitive touch-based applications for the growing Internet of Things (IoT) market. Renesas’ innovative touch sensor intellectual property (IP) core achieves both high noise immunity and high sensitivity, offering touch key operation on wet and curved touch panels.
Based on Renesas’ RX CPU core, the RX113 Group of MCUs delivers the highest performance, lowest power, advanced connectivity and extensive digital signal processing (DSP) capability compared to other entry-level 32-bit MCUs. In addition to a capacitive-touch sensing unit and unprecedented ultra-low power, these full-featured 32-bit MCUs also support LCD control, USB 2.0, audio and more. The RX113 devices support multiple memory configurations and communications peripherals to keep pace with expanding embedded systems design requirements, including:
• Up to 512 KB of flash memory and 64 KB of SRAM
• Segment LCD control/drive capability up to 288 segments for support of the latest system displays
• I2S for audio processing, SSI (Serial Sound Interface) and SPI (serial peripheral interface) protocols
• 12-bit ADC (analog-to-digital converter) with internal voltage reference, and a 12-bit DAC (digital-to-analog converter) and a temperature sensor
• Complete DSP Processing capability, including Hardware-based Divide, for efficient near-sensor processing
Capacitive Touch Sensing Technology Provides Superior Features and Capabilities
The RX113 MCUs support both mutual- and self-capacitance methods for key manipulation detection. The Capacitive Touch sensing unit supports up to 36 channels of key input (in mutual-capacitance mode). The self-capacitance method provides significantly improved noise immunity and sensitivity compared to previous implementations. The new MCUs also support Renesas Electronics’ first mutual-capacitance method, which allows touch key operation even when the user is wearing gloves and is highly resistant to incorrect detection even when there is water on the touch key area itself. The Capacitive Touch sensing unit supports acrylic panels over 10 mm thick, which allows for flexible designs, such as those using curved panels, to be implemented. Renesas has improved the sensitivity by approximately 5 times, enabling user interfaces with non-traditional surfaces (e.g., wet panels or gloves) to be implemented.
True Low Power Technology
The RX Family delivers flexible power management and optimum power consumption for all use cases. The 32-bit RX113 MCUs achieve the industry’s highest level of power efficiency, featuring operating mode power consumption as low as 0.1 mA/MHz (typical) and only 0.44 µA power consumption in low-power mode (RAM contents retained). They also achieve power consumption as low as 1.6 µA in LCD drive mode (internal step-up and 1/3 bias operation).
The RX113 Group has three different run modes, three low-power modes and a flexible clock system. For instance, the Low Power Fast Wakeup capability enables the MCUs to operate at 0.1 mA/MHz in Run Mode and 0.44 µA in software standby from which it can wake-up in only 4.8 µs. It integrates a Zero Wait State Flash with Erase/Write as low as 1.8 V, 1 KB erase block size and background operation (BGO), and offers erase times as low as 10 ms per block.
Renesas provides a comprehensive development ecosystem for the RX Family, including e2 studio, a powerful Eclipse-based IDE, as well as compilers, debuggers, code generation tools and flash programmers. The RX113 devices will be supported by the extensive RX ecosystem, comprising a wide range of third-party tools, RTOS, and middleware. Support for the IAR compiler and IAR Embedded Workbench IDE and for the Micrium RTOS and Spectrum components is readily available at this time.