Document Number: MPR121
Rev. 4, 02/2013
Freescale Semiconductor
Data Sheet: Technical Data
An Energy Efficient Solution by Freescale
© 2009-2011, 2013 Freescale Semiconductor, Inc. All rights reserved.
Proximity Capacitive Touch
Sensor Controller
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 I
2
C address, an
expanded filtering system with debounce, and completely independent
electrodes with built-in autoconfiguration. The device also features a 13
th
simulated electrode which represents the simultaneous charging of all the
electrodes connected together. When used with a touch panel or touch
screen array, the 13
th
simulated electrode allows a greater near proximity
detection distance and an increased sensing area.
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
•I
2
C interface, with IRQ Interrupt output to advise electrode status
changes
• 3 mm x 3 mm x 0.65 mm 20 lead QFN package
• -40°C to +85°C operating temperature range
Implementations
• General Purpose Capacitance Detection
• Switch Replacements
• Touch Pads, Touch Wheel, Touch Slide Bar, Touch Screen Panel
• Capacitance Near Proximity Detection
Typical Applications
• PC Peripherals
• MP3 Players
• Remote Controls
• Mobile Phones
• Lighting Controls
ORDERING INFORMATION
Device Name Temperature Range Case Number Touch Pads
I
2
C Address
Shipping
MPR121QR2 -40°C to +85°C 2059 (20-Pin QFN) 12-pads 0x5A - 0x5D Tape & Reel
MPR121
Top View
Pin Connections
Bottom View
20-PIN QFN
CASE 2059-01
1
2
3
5
678910
12
11
13
14
15
1617181920
4
13
ELE4
ELE3
ELE6
ELE7
ELE5
V
SS
REXT
ELE0
ELE1
ADDR
V
REG
SCL
IRQ
SDA
ELE2
V
DD
ELE11
ELE10
ELE9
ELE8
