MPR121QR2 Freescale Semiconductor, MPR121QR2 Datasheet - Page 27

• 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
NOISE HALF DELTA (NHD)
NOISE COUNT LIMIT (NCL)
Table 24. Noise Count Limit Register Field Descriptions
Table 23. Noise Half Delta Register Field Descriptions
Field
NCL
7:0
Reset:
Reset:
Field
NHD
5:0
W
W
R
R
Noise Count Limit – The Noise Count Limit determines the number of samples consecutively greater
than the Max Half Delta necessary before it can be determined that it is non-noise.
00000000 Encoding 0 – Sets the Noise Count Limit to 1 (every time over Max Half Delta)
00000001 Encoding 1 – Sets the Noise Count Limit to 2 consecutive samples over Max Half Delta
~
11111111 Encoding 255 – Sets the Noise Count Limit to 255 consecutive samples over Max Half Delta
7
0
0
7
0
= Unimplemented
Noise Half Delta – The Noise Half Delta determines the incremental change when
non-noise drift is detected.
000000 DO NOT USE THIS CODE
000001 Encoding 1 – Sets the Noise Half Delta to 1
~
111111 Encoding 63 – Sets the Noise Half Delta to 63
= Unimplemented
6
0
0
6
0
Figure 26. Noise Count Limit Register
Figure 25. Noise Half Delta Register
5
0
5
0
4
0
4
0
NCL
Description
Description
3
0
3
0
NHD
2
0
2
0
1
0
1
0
0
0
0
0
MPR121
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