ELECTRONICS: Freescale Semiconductor has expanded its broad portfolio of touch sensing solutions with the addition of the MPR121 ultra-low-power capacitive sensor and a touch sensing software (TSS) suite compatible with more than 300 of its 8-bit microcontrollers (MCUs). With these new offerings, Freescale enables customers to choose the best fit for their interface designs across a broad spectrum of consumer and industrial applications.
Freescale’s second-generation MPR121 capacitive touch sensor provides highly reliable touch detection through increased electrode count and integration of automatic calibration and area detection systems. The 12-pad touch sensor is available in the industry’s smallest lead-free package and offers the lowest power consumption at 29 μA average supply current, helping OEMs meet aggressive power targets.
Ideal for portable, low-power consumer electronics applications, the MPR121 touch sensor has been selected to enable compelling features for the newest MP3 players from Audiovox.
The TSS suite provides an alternate solution by enabling the integration of touch sensing functionality into applications based on Freescale 8-bit MCUs. The suite speeds development by delivering pre-configured software that enables a range of popular features including rotary, slider and keypad functionality. The complimentary software also helps lower system cost by eliminating the need for additional sensor silicon in many designs.
Freescale’s touch sensing solutions enable sleek interface designs for a variety of consumer and industrial applications. Freescale’s broad portfolio of touch sensing solutions allows customers to select the option that meets their specific system requirements for power, software integration and quantity of touch points.
Customers can choose a 3- or 12-pad Freescale sensor or the touch-sensing software solution for a variety of applications.
The MPR121 is Freescale’s second-generation sensor controller, following the MPR03x series devices. The MPR121 features increased internal intelligence and includes Freescale’s second-generation capacitance detection engine. Major additions to the MPR121 include an increased electrode count for more reliable touch detection, a hardware-configurable I2C address, an expanded filtering system with debounce and completely independent electrodes with auto-configuration built in.
Features include: Support for up to 12 touch electrodes, plus proximity function, 1.71 V to 3.6 V operation, extremely low power, with 29 μA average supply current All 12 electrodes monitored with 16 ms (62.5Hz) sample rate, continuous independent auto-calibration for each electrode, separate touch and release trip thresholds for each electrode, provides hysteresis and electrode independence, drives up to eight LEDs or provides up to eight logic I/Os in any combination, 3 μA maximum shutdown current, I²C interface with IRQ output to advise electrode status changes, a 3 x 3 x 0.6 mm 20-lead QFN package and -40 to 85C operating temperature range.
Touch sensing software suite features
The TSS suite works with Freescale’s portfolio of S08 MCUs and the CodeWarrior® development environment. The software package includes an evaluation and demo board, demonstration and implementation examples, technical documentation, hardware design guidelines and online training and support.
Features include: Up to 64 electrodes, possibility to have different electrode arrays at the same time: keypad, slider, rotary, matrix, touchpad or any combination, supports multiple communication protocols: I2C, LIN, CAN , SPI and USB, eliminates the need for an extra IC to provide touch sensing capability, possibility to have other peripherals working at the same time: LCD, LEDs, buzzers, ADC and other sensors, 1.8 to 5.5V operational voltage, fully compatible with more than 300 Freescale S08 MCU devices, supports a broad range of packages from QFN8 (4×4x1) up to LQFP100 (14X14X1.4).
- Edited by Liz Taurasi