MMA8452QR1 Freescale Semiconductor, MMA8452QR1 Datasheet - Page 14

• 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

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detect events and notify an external microprocessor over interrupt lines. The functionality includes the following:
functions. Separate application notes have been provided to help configure the device for each embedded functionality.
5.1
Volatile Memory (NVM). On power-up, the trim parameters are read from NVM and applied to the circuitry. In normal use, further
calibration in the end application is not necessary. However, the MMA8452Q allows the user to adjust the Zero-g offset for each
axis after power-up, changing the default offset values. The user offset adjustments are stored in 6 volatile registers. For more
information on device calibration, refer to Freescale application note, AN4069.
5.2
OUT_Z_LSB registers as 2’s complement 12-bit numbers. The most significant 8-bits of each axis are stored in OUT_X (Y ,
Z)_MSB, so applications needing only 8-bit results can use these 3 registers and ignore OUT_X,Y , Z_LSB. To do this, the
F_READ bit in CTRL_REG1 must be set. When the F_READ bit is cleared, the fast read mode is disabled.
(1 mg) at 12-bits resolution. When the full-scale is set to 8g, the measurement range is -8g to +7.996g, and each count
corresponds to 1g/256 (3.9 mg) at 12-bits resolution. The resolution is reduced by a factor of 16 if only the 8-bit results are used.
For more information on the data manipulation between data formats and modes, refer to Freescale application note, AN4076.
There is a device driver available that can be used with the Sensor T oolbox demo board (LFSTBEB8451, 2, 3Q) with this
application note.
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MMA8452Q
The MMA8452Q is a low-power, digital output 3-axis linear accelerometer with a I
All functionality is available in 2g, 4g or 8g dynamic ranges. There are many configuration settings for enabling all the different
The device interface is factory calibrated for sensitivity and Zero-g offset for each axis. The trim values are stored in Non
The measured acceleration data is stored in the OUT_X_MSB, OUT_X_LSB, OUT_Y_MSB, OUT_Y_LSB, OUT_Z_MSB, and
When the full-scale is set to 2g, the measurement range is -2g to +1.999g, and each count corresponds to 1g/1024
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8-bit or 12-bit data which includes High Pass Filtered data
4 different oversampling options for compromising between resolution and current consumption based on application
requirements
Additional Low Noise mode that functions independently of the Oversampling modes for higher resolution
Low Power and Auto-WAKE/SLEEP for conservation of current consumption
Single/Double tap with directional information 1 channel
Motion detection with directional information or Freefall 1 channel
Transient/Jolt detection based on a high pass filter and settable threshold for detecting the change in acceleration above
a threshold with directional information 1 channel
Portrait/Landscape detection with trip points fixed at 30° and 60° for smooth transitions between orientations.
Functionality
Device Calibration
8-bit or 12-bit Data
2
C interface and embedded logic used to
Freescale Semiconductor
Sensors