Document Number: MMA7455L Freescale Semiconductor Rev 10, 12/2009 Technical Data 2g/4g/8g Three Axis Low-g Digital Output Accelerometer MMA7455L 2 The MMA7455L is a Digital Output (I C/SPI), low power, low profile capacitive micromachined accelerometer featuring signal conditioning, a low pass filter, temperature compensation, self-test, configurable to detect 0g through interrupt pins (INT1 or INT2), and pulse detect for quick motion detection. 0g offset and sensitivity are factory set and require no external MMA7455L: XYZ-AXIS devices. The 0g offset can be customer calibrated using assigned 0g registers ACCELEROMETER and g-Select which allows for command selection for 3 acceleration ranges 2g/4g/8g (2g/4g/8g). The MMA7455L includes a Standby Mode that makes it ideal for handheld battery powered electronics. Features 2 Digital Output (I C/SPI) Bottom View 3mm x 5mm x 1mm LGA-14 Package Self-Test for Z-Axis Low Voltage Operation: 2.4 V 3.6 V User Assigned Registers for Offset Calibration Programmable Threshold Interrupt Output Level Detection for Motion Recognition (Shock, Vibration, Freefall) Pulse Detection for Single or Double Pulse Recognition Sensitivity (64 LSB/g 2g and 8g in 10-Bit Mode) 14 LEAD Selectable Sensitivity (2g, 4g, 8g) for 8-bit Mode LGA Robust Design, High Shocks Survivability (5,000g) CASE 1977-01 RoHS Compliant Environmentally Preferred Product Low Cost Top View Typical Applications Cell Phone/PMP/PDA: Image Stability, Text Scroll, Motion Dialing, Tap to Mute HDD: Freefall Detection Laptop PC: Freefall Detection, Anti-Theft DVDD IO SDA/SDI/SDO Pedometer GND SDO Motion Sensing, Event Recorder N/C N/C IADDR0 N/C ORDERING INFORMATION INT2 GND Part Number Temperature Range Package Shipping AVDD INT1/DRDY MMA7455LT 40 to +85C LGA-14 Tray MMA7455LR1 40 to +85C LGA-14 7 Tape & Reel MMA7455LR2 40 to +85C LGA-14 13 Tape & Reel Figure 1. Pin Connections This document contains certain information on a new product. Specifications and information herein are subject to change without notice. Freescale Semiconductor, Inc., 2007-2009. All rights reserved. 65 4 3 2 1 CS 7 14 SCL/SPC 8 9 10 11 12 13Contents ELECTRO STATIC DISCHARGE (ESD) ......................................................................................................................................6 PRINCIPLE OF OPERATION ......................................................................................................................................................8 FEATURES ..................................................................................................................................................................................9 Self-Test .........................................................................................................................................................................9 g-Select ..........................................................................................................................................................................9 Standby Mode ................................................................................................................................................................9 Measurement Mode .......................................................................................................................................................9 LEVEL DETECTION ...................................................................................................................................................................10 18: Control 1 (Read/Write) Setting the Detection Axes for X, Y and Z .......................................................................10 19: Control 2 (Read/Write) Motion Detection (OR Condition) or Freefall Detection (AND Condition) ........................10 18: Control 1 (Read/Write): Setting the threshold to be an integer value or an absolute value .................................10 1A: Level Detection Threshold Limit Value (Read/Write) ...........................................................................................10 THRESHOLD DETECTION FOR MOTION AND FREEFALL CONDITIONS ............................................................................11 CASE 1: Motion Detection ...........................................................................................................................................11 CASE 2: Motion Detection ...........................................................................................................................................11 CASE 3: Freefall Detection ..........................................................................................................................................11 CASE 4: Freefall Detection ..........................................................................................................................................11 PULSE DETECTION ..................................................................................................................................................................12 18: Control 1 (Read/Write): Disable X, Y or Z for Pulse Detection .............................................................................12 19: Control 2 (Read/Write): Motion Detection (OR condition) or Freefall Detection (AND condition) ........................12 CASE 1: Single Pulse Motion Detection: X or Y or Z > Pulse Threshold for Time < Pulse Duration ..........................12 CASE 2: Freefall Detection: X and Y and Z < Pulse Threshold for Time > Latency Time ...........................................13 CASE 3: Double Pulse Detection: X OR Y OR Z > Threshold for Pulse Duration1 < PDTime1, Latency Time, .........14 ASSIGNING, CLEARING & DETECTING INTERRUPTS ..........................................................................................................15 Clearing the Interrupt Pins: Register 17 .....................................................................................................................15 Detecting Interrupts ......................................................................................................................................................16 DIGITAL INTERFACE ................................................................................................................................................................16 2 I C Slave Interface .......................................................................................................................................................16 SPI Slave Interface ......................................................................................................................................................18 BASIC CONNECTIONS .............................................................................................................................................................19 Pin Descriptions ...........................................................................................................................................................19 Recommended PCB Layout for Interfacing Accelerometer to Microcontroller .............................................................19 REGISTER DEFINITIONS .........................................................................................................................................................21 SOLDERING AND MOUNTING GUIDELINES FOR THE LGA ACCELEROMETER SENSOR TO A PC BOARD ...................29 MMA7455L Sensors Freescale Semiconductor 2