MMA8451QT Freescale Semiconductor, MMA8451QT Datasheet - Page 32

• Manufacturer Part Number: MMA8451QT
• Description: Board Mount Accelerometers LOW G 3-AXIS 14BT EX VLT
• Manufacturer: Freescale Semiconductor

Specifications of MMA8451QT

• Sensing Axis: X, Y, Z
• Acceleration: 2 g, 4 g, 6 g
• Digital Output - Number Of Bits: 8 bit, 14 bit
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.95 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Digital Output - Bus Interface: I2C
• Shutdown: Yes
• Sensitivity: 1024 count/g, 2048 count/g, 4096 count/g
• Package / Case: QFN-16
• Output Type: Digital
• Acceleration Range: ± 2g, ± 4g, ± 8g
• No. Of Axes: 3
• Ic Interface Type: I2C, Serial
• Sensor Case Style: QFN
• No. Of Pins: 16
• Supply Voltage Range: 1.95V To 3.6V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

0x18 FF_MT_COUNT Debounce Register
selected for the freefall, motion event.
counter will never increase beyond the FF_MT_COUNT value. Time step used for the debounce sample count depends on the
ODR chosen and the Oversampling mode as shown in
Table 29. FF_MT_COUNT Description
32
0x18 FF_MT_COUNT_Register (Read/Write)
MMA8452Q
This register sets the number of debounce sample counts for the event trigger.
This register sets the minimum number of debounce sample counts of continuously matching the detection condition user
When the internal debounce counter reaches the FF_MT_COUNT value a Freefall/Motion event flag is set. The debounce
Bit 7
D7
D[7:0]
Table 30. FF_MT_COUNT Relationship with the ODR
ODR (Hz)
12.5
6.25
1.56
800
400
200
100
50
Count value. Default value: 0000_0000
Bit 6
D6
Normal
0.319
0.638
1.28
2.55
5.1
5.1
5.1
5.1
Max Time Range (s)
LPLN
0.319
0.638
1.28
2.55
20.4
20.4
20.4
5.1
Bit 5
D5
HighRes
0.319
0.638
0.638
0.638
0.638
0.638
0.638
0.638
Bit 4
D4
Table
0.319
0.638
1.28
2.55
20.4
40.8
40.8
5.1
LP
30.
Normal
Bit 3
D3
1.25
2.5
10
20
20
20
20
5
LPLN
1.25
2.5
10
20
80
80
80
5
Time Step (ms)
Bit 2
D2
HighRes
1.25
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Bit 1
Freescale Semiconductor
D1
1.25
160
160
LP
2.5
10
20
80
5
Bit 0
D0
Sensors