MMA8450QT Freescale Semiconductor, MMA8450QT Datasheet - Page 32

• Manufacturer Part Number: MMA8450QT
• Description: Board Mount Accelerometers 12bit 3-Axis FIFO HPF PL
• Manufacturer: Freescale Semiconductor

Specifications of MMA8450QT

• Sensing Axis: X, Y, Z
• Acceleration: 2 g, 4 g, 8 g
• Digital Output - Number Of Bits: 12 bit
• Supply Voltage (max): 1.89 V
• Supply Voltage (min): 1.71 V
• Supply Current: 3 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Shutdown: Yes
• Sensitivity: 0.976 mg/digit, 1.953 mg/digit, 3.906 mg/digit
• Package / Case: QFN-16
• Output Type: Digital
• Package Type: QFN
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 3mm
• Product Height (mm): 1mm
• Product Length (mm): 3mm
• Mounting: Surface Mount
• Pin Count: 16
• 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: 1.71V To 1.89V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 32. Landscape-to-Portrait Trip Angle Thresholds Look-up Table
6.4
AN3917.
Note: There are two Freefall and Motion Detection Functions. The registers from 0x27 - 0x2A have the same descriptions as
0x23: FF_MT_CFG_1 Freefall and Motion Configuration Register 1
OAE bit allows the selection between Motion (logical OR combination of X, Y, Z-axis event flags) and Freefall (logical AND
combination of X, Y, Z-axis event flags) detection.
ELE denotes whether the enabled event flag will be latched in the FF_MT_SRC_1 register or the event flag status in the
FF_MT_SRC_1 will indicate the real-time status of the event. If ELE bit is set to a logic 1, then the event active “EA” flag is cleared
by reading the FF_MT_SRC_1 source register.
ZHEFE
higher than the threshold set in FF_MT_THS_1 register.
ZLEFE, YLEFE, XLEFE
than the threshold set in FF_MT_THS_1 register.
FF_MT_THS_1 is the threshold register used by the Freefall/Motion function to detect Freefall or Motion events. The unsigned
7-bit FF_MT_THS_1 threshold register holds the threshold for the low g event detection where the magnitude of the X and Y and
Z acceleration values are lower than the threshold value. Conversely the FF_MT_THS_1 also holds the threshold for the high g
event detection where the magnitude of the X, or Y, or Z-axis acceleration values is higher than the threshold value.
32
0x23 FF_MT_CFG_1 Register (Read/Write)
Table 33. FF_MT_CFG_1 Description
MMA8450Q
For details on how to configure the device for Freefall and/or Motion detection and for sample code, refer to application note
ZHEFE
YHEFE
XHEFE
ZLEFE
YLEFE
XLEFE
Landscape-to-Portrait
OAE
Bit 7
ELE
ELE
registers 0x23 - 0x26.
,
YHEFE
Trip Angle
Freefall & Motion Detection Registers
30
35
40
45
50
55
60
65
70
75
Event Latch Enable: Event flag is latched into FF_MT_SRC_1 register. Reading of the FF_MT_SRC_1 register clears the EA
event flag. Default value: 0.
0: Event flag latch disabled; 1: Event flag latch enabled
Logical Or/And combination of events flags. Default value: 0.
0: Logical AND combination of events flags; 1: Logical OR combination of events flags
Event flag enable on Z High event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
Event flag enable on Z Low event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
Event flag enable on Y High event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
Event flag enable on Y Low event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
Event flag enable on X High event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
Event flag enable on X Low event. Default value: 0.
0: Event detection disabled; 1: Event detection enabled
,
XHEFE
Bit 6
OAE
enables the detection of a low g event when the measured acceleration data on X, Y, or Z-axis is lower
enables the detection of a high g event when the measured acceleration data on X, Y, or Z-axis is
ZHEFE
Bit 5
PL_L_P_THS_REG1
0x1D
0x2D
0x1A
0x1B
0x20
0x23
0x27
0x35
0x42
0x57
ZLEFE
Bit 4
YHEFE
Bit 3
PL_L_P_THS_REG2
0x22
0x92
0x92
0x00
0x31
0x71
0x41
0x91
0x31
0x71
YLEFE
Bit 2
XHEFE
Bit 1
PL_L_P_THS_REG3
Freescale Semiconductor
0xD4
0xD9
0xA2
0x77
0x33
0x00
0xB9
0x8F
0x81
0x77
XLEFE
Bit 0
Sensors