MMA8452QR1 Freescale Semiconductor, MMA8452QR1 Datasheet - Page 28

• Manufacturer Part Number: MMA8452QR1
• Description: Board Mount Accelerometers LOW G 3-AXIS 12BT EX VLT
• Manufacturer: Freescale Semiconductor

Specifications of MMA8452QR1

• Sensing Axis: X, Y, Z
• Acceleration: 2 g, 4 g, 8 g
• Digital Output - Number Of Bits: 8 bit, 12 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: 256 count/g, 512 count/g, 1024 count/g
• Package / Case: QFN-16
• Output Type: Digital
• Rohs Compliant: Yes
• Peak Reflow Compatible (260 C): Yes
• Acceleration Range: ± 2g, ± 4g, ± 8g
• No. Of Axes: 3
• Ic Interface Type: I2C
• Sensor Case Style: QFN
• No. Of Pins: 16
• Supply Voltage Range: 1.95V To 3.6V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

0x11 Portrait/Landscape Configuration Register
0x12 Portrait/Landscape Debounce Counter
data rate set by the product of the selected system ODR and PL_COUNT registers. Any transition from WAKE to SLEEP or vice
versa resets the internal Landscape/Portrait debounce counter. Note: The debounce counter weighting (time step) changes
based on the ODR and the Oversampling mode.
modes.
0x13: PL_BF_ZCOMP Back/Front and Z Compensation Register
Note: All angles are accurate to ±2°.
Table 20. PL_CFG Description
Table 21. PL_COUNT Description
Table 22. PL_COUNT Relationship with the ODR
Table 23. PL_BF_ZCOMP Description
28
0x13: PL_BF_ZCOMP Register (Read/Write)
MMA8452Q
0x11 PL_CFG Register (Read/Write)
0x12 PL_COUNT Register (Read/Write)
DBCNE[7:0]
ZLOCK[2:0]
This register enables the Portrait/Landscape function and sets the behavior of the debounce counter.
This register sets the debounce count for the orientation state transition. The minimum debounce latency is determined by the
The Z-Lock angle compensation is set to 29°. The Back to Front trip angle is set to ±75°.
DBNCE[7]
ODR (Hz)
BKFR[7:6]
DBCNTM
DBCNTM
PL_EN
BKFR[1]
Bit 7
12.5
6.25
1.56
800
400
200
100
50
Bit 7
Bit 7
Debounce counter mode selection. Default value: 1
0: Decrements debounce whenever condition of interest is no longer valid.
1: Clears counter whenever condition of interest is no longer valid.
Portrait/Landscape Detection Enable. Default value: 0
0: Portrait/Landscape Detection is Disabled.
1: Portrait/Landscape Detection is Enabled.
Debounce Count value. Default value: 0000_0000.
Back Front Trip Angle Fixed Threshold = 01 which is
Z-Lock Angle Fixed Threshold = 100 which is 29°.
Normal
DBNCE[6]
0.319
0.638
1.28
2.55
5.1
5.1
5.1
5.1
Bit 6
PL_EN
BKFR[0]
Bit 6
Bit 6
Max Time Range (s)
LPLN
0.319
0.638
1.28
2.55
20.4
20.4
20.4
5.1
DBNCE[5]
Bit 5
Bit 5
Bit 5
HighRes
0
0
0.319
0.638
0.638
0.638
0.638
0.638
0.638
0.638
DBNCE[4]
Table 22
Bit 4
explains the time step value for all sample rates and all Oversampling
Bit 4
0.319
0.638
1.28
2.55
20.4
40.8
40.8
Bit 4
0
5.1
LP
0
DBNCE[3]
≥
Bit 3
±75°.
Normal
Bit 3
1.25
0
2.5
10
20
20
20
20
5
Bit 3
0
DBNCE[2]
Bit 2
ZLOCK[2]
LPLN
1.25
Bit 2
2.5
10
20
80
80
80
5
Bit 2
Time Step (ms)
0
DBNCE[1]
HighRes
Bit 1
ZLOCK[1]
1.25
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Bit 1
Freescale Semiconductor
Bit 1
0
DBNCE[0]
ZLOCK[0]
Bit 0
1.25
160
160
2.5
Bit 0
LP
10
20
80
Bit 0
5
Sensors
0