Freescale MPR121 Touch Sensor and Touch Sensing Suite

Freescale Semiconductor introduced 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). The Freescale MPR121 capacitive touch sensor offers 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.

Samples of the MPR121 touch sensor are available now, with production quantities planned for November 2009. Suggested resale pricing in 10,000-piece quantities is 78 cents (USD). The KITMPR121EVM Touch Sensor Kit, part of the Freescale Sensor Toolbox, provides sample electrodes with demo software and is available at a suggested resale price of $99 (USD). The TSS Suite is available to download now, free of charge, to Freescale MCU customers. In addition, a Touch Sensing Software evaluation board (TSSEVB) is available at a suggested introductory resale price of $79 (USD). The board is designed to provide customers with the technology necessary to begin creating touch sensing applications right away with Freescale MCUs.

Freescale MPR121 Touch Sensor Features

  • 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
  • 3 x 3 x 0.6 mm 20-lead QFN package
  • -40°C to +85°C operating temperature range

Freescale Touch Sensing Software (TSS) Suite Features

  • 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 V to 5.5 V operational voltage
  • Fully compatible with more than 300 Freescale S08 MCU devices
  • Supports a broad range of packages from QFN8 (4x4x1) up to LQFP100 (14X14X1.4)

More info: Freescale Touch Sensor Solutions