MPR121 Proximity Capacitive Touch Sensor Controller

A Touch Smarter

The Freescale Semiconductor MPR121 Proximity Capacitive Touch Sensor Controller is a second generation device with advanced intelligence features that provide more reliable touch detection with increased electrode count. The Freescale Semiconductor MPR121 features 12 electrodes with an intelligent, flexible independent calibration feature that simplifies designing numerous touch applications for portable low-power electronic products.

This Freescale proximity capacitive touch sensor controller builds on the MPR031 proximity touch sensor, adding an updated configuration system without increasing complexity. The MPR121 also includes a hardware configurable I²C address, an expanded filtering system with debounce, and completely independent electrodes with autoconfiguration built in. A 13th simulated electrode represents the simultaneous charging of all the electrodes connected together to allow for increased proximity detection in a touch panel touch screen array.

• 1.71 V to 3.6 V operation
  
• 29 μA supply current at 16 ms sample period
  
• 3 μA shutdown current
  
• 12 electrodes
  
• Continuous independent auto-calibration for each electrode input
  
• Separate touch and release trip thresholds for each electrode,
  providing hysteresis and electrode independence
  
• I²C interface, with IRQ output to advise electrode status changes
  
• 3 mm x 3 mm x 0.65 mm 20 lead QFN package
  
• LED driver functionality with 8 shared LEDs
  
• -40°C to +85°C operating temperature range

• Elimination of mechanical buttons
  
• Enhances reliability by eliminating mechanical wear and tear
  
• User interface controllers that manage multiple configurations
  
• Gives greater flexibility to product designers
  
• Reduces overall system cost

• Switch Replacements
  
• Touch Pads

• PC Peripherals
  
• MP3 Players
  
• Remote Controls
  
• Mobile Phones
  
• Lighting Controls