Data Sheet

Sensors
2 Freescale Semiconductor
MMA8452Q
Contents
1 Block Diagram and Pin Description .................................................................................................................................. 3
1.1 Soldering Information .................................................................................................................................................. 5
2 Mechanical and Electrical Specifications ......................................................................................................................... 6
2.1 Mechanical Characteristics ......................................................................................................................................... 6
2.2 Electrical Characteristics ............................................................................................................................................. 7
2.3 I
2
C Interface Characteristic ......................................................................................................................................... 8
2.4 Absolute Maximum Ratings ........................................................................................................................................ 9
3 Terminology ...................................................................................................................................................................... 10
3.1 Sensitivity .................................................................................................................................................................. 10
3.2 Zero-g Offset ............................................................................................................................................................. 10
3.3 Self-Test .................................................................................................................................................................... 10
4 Modes of Operation .......................................................................................................................................................... 10
5 Functionality ...................................................................................................................................................................... 11
5.1 Device Calibration ..................................................................................................................................................... 11
5.2 8-bit or 12-bit Data .................................................................................................................................................... 11
5.3 Low Power Modes vs. High Resolution Modes ......................................................................................................... 12
5.4 Auto-WAKE/SLEEP Mode ........................................................................................................................................ 12
5.5 Freefall and Motion Detection ................................................................................................................................... 12
5.5.1 Freefall Detection ........................................................................................................................................... 12
5.5.2 Motion Detection ............................................................................................................................................ 12
5.6 Transient Detection ................................................................................................................................................... 13
5.7 Tap Detection ............................................................................................................................................................ 13
5.8 Orientation Detection ................................................................................................................................................ 13
5.9 Interrupt Register Configurations .............................................................................................................................. 15
5.10 Serial I
2
C Interface .................................................................................................................................................... 15
5.10.1 I
2
C Operation ................................................................................................................................................. 16
6 Register Descriptions ....................................................................................................................................................... 18
6.1 Data Registers ............................................................................................................................................................ 9
6.2 Portrait/ Landscape Embedded Function Registers ................................................................................................. 24
6.3 Motion and Freefall Embedded Function Registers .................................................................................................. 26
6.4 Transient (HPF) Acceleration Detection ................................................................................................................... 31
6.5 Single, Double and Directional Tap Detection Registers.......................................................................................... 33
6.6 Auto-WAKE/SLEEP Detection .................................................................................................................................. 37
6.7 Control Registers ...................................................................................................................................................... 38
6.8 User Offset Correction Registers .............................................................................................................................. 41