MPR121QR2 Freescale Semiconductor, MPR121QR2 Datasheet - Page 53

• Manufacturer Part Number: MPR121QR2
• Description: IC CTLR TOUCH SENSOR 20-QFN
• Manufacturer: Freescale Semiconductor
• Type: Capacitive, Proximity Sensorr

Specifications of MPR121QR2

• Number Of Inputs/keys: 12 Key
• Data Interface: I²C, Serial
• Voltage - Supply: 1.71 V ~ 3.6 V
• Current - Supply: 29µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-UQFN, 20-µQFN
• Output Type: Logic
• Interface: I²C
• Input Type: Logic
• Supply Voltage: 2.5 V to 3.6 V
• Dimensions: 3 mm L x 3 mm W x 0.65 mm H
• Temperature Range: - 40 C to + 85 C
• Termination Style: SMD/SMT
• Supply Current: 29µA
• Ic Interface Type: I2C
• Supply Voltage Range: 1.71V To 3.6V
• Sensor Case Style: QFN
• No. Of Pins: 20
• Operating Temperature Range: -40°C To +85°C
• Interface Type: I2C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MPR121QR2; MPR121QR2TR

Sensors
Freescale Semiconductor
Section E
Section F
CONCLUSION
activities as well as in the production implementation.
In many applications for the MPR121, the default settings presented in this document will be sufficient for both design time
Register Address
Register Address
0x7D
0x5E
0x7B
0x7E
0x7F
Description: This register controls the number of electrodes being enabled and the mode the device is in. There
Description: These are the settings used for the Auto Configuration. They enable AUTO-CONFIG and
Variation: During debug of a system, this register will change between the number of electrodes and 0x00
Variation: In most cases these values will never need to be change, but if a case arises, a full description is
Electrode Configuration
are only two modes, Standby (when the value is 0x00) and Run (when the value of the lower bit is
non-zero). The default value shown enables all 12 electrodes by writing decimal 12 or hex 0x0C to
the register. Typically other registers cannot be changed while the part is running so this register
should always be written last.
every time a register needs to change. In a production system, this register will only need to be
written when the mode is changed from Standby to Run or vise versa.
AUTO-CONFIG Control Register 0
AUTO-CONFIG USL Register
AUTO-CONFIG LSL Register
AUTO-CONFIG Target Level Register
AUTO_RECONFIG. In addition they set the target range for the baseline. The upper limit is set to
190, the target is set to 180 and the lower limit is set to 140.
found in application note AN3889.
Register Name
Register Name
Value
Value
0x0C
0x0B
0x9C
0x8C
0x65
Application Note
Application Note
AN3890
AN3889
AN3889
AN3889
AN3889
MPR121
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