MPR121QR2

The MPR121 is the second generation sensor controller following the initial release of the MPR03x series of devices. The MPR121 features an increased internal intelligence plus Freescale's second generation capacitance detection engine. Some major enhancements include an increased electrode count, a hardware configurable I²C address, an expanded filtering system with debounce, and completely independent electrodes with built- in autoconfiguration. The device also features a 13th simulated electrode which represents the simultaneous charging of all the electrodes connected together. When used with a touch panel or touch screen array, the 13th simulated electrode allows a greater near proximity detection distance and an increased sensing area.

Applications

• General Purpose Capacitance Detection
• Switch Replacements
• Touch Pads, Touch Wheel, Touch Slide Bar, Touch Screen Panel
• Capacitance Near Proximity Detection
• PC Peripherals
• MP3 Players
• Remote Controls
• Mobile Phones
• Lighting Controls

Key features

• 1.71V to 3.6V operation
• 29 μA typical run current at 16 ms sampling interval
• 3 μA in scan stop mode current
• 12 electrodes/capacitance sensing inputs in which 8 are multifunctional for LED driving and GPIO
• Integrated independent autocalibration for each electrode input
• Autoconfiguration of charge current and charge time for each electrode input
• Separate touch and release trip thresholds for each electrode, providing hysteresis and electrode independence
• I²C interface, with IRQ Interrupt output to advise electrode status changes
• 3 mm × 3 mm × 0.65 mm 20 lead QFN package
• -40°C to +85°C operating temperature range