The MMA8451Q is a smart low-power, three-axis, capacitive micromachined accelerometer with 14 bits of resolution. This accelerometer is packed with embedded functions with flexible user programmable options, configurable to two interrupt pins. Embedded interrupt functions allow for overall power savings relieving the host processor from continuously polling data. There is access to both low-pass filtered data as well as high-pass filtered data, which minimizes the data analysis required for jolt detection and faster transitions. The device can be configured to generate inertial wakeup interrupt signals from any combination of the configurable embedded functions allowing the MMA8451Q to monitor events and remain in a low power mode during periods of inactivity. The MMA8451Q is available in a 3 mm by 3 mm by 1 mm QFN package.

特性 Features

? 1.95V to 3.6V supply voltage

? 1.6V to 3.6V interface voltage

? ±2g/±4g/±8g dynamically selectable full-scale

? Output Data Rates (ODR) from 1.56 Hz to 800 Hz

? 99 μg/√Hz noise

? 14-bit and 8-bit digital output

? I2C digital output interface (operates to 2.25 MHz with 4.7 kΩ pullup)

? Two programmable interrupt pins for seven interrupt sources

? Three embedded channels of motion detection

? Freefall or Motion Detection: 1 channel

? Pulse Detection: 1 channel

? Jolt Detection: 1 channel

? Orientation (Portrait/Landscape) detection with programmable hysteresis

? Automatic ODR change for Auto-WAKE and return to SLEEP

? 32-sample FIFO

? High-Pass Filter Data available per sample and through the FIFO

? Self-Test

? RoHS compliant

? Current Consumption: 6 μA – 165 μA

Typical Applications

? eCompass applications

? Static orientation detection (Portrait/Landscape, Up/Down, Left/Right, Back/

Front position identification)

? Notebook, eReader and Laptop Tumble and Freefall Detection

? Real-time orientation detection (virtual reality

and gaming 3D user position feedback)

? Real-time activity analysis (pedometer step counting, freefall drop detection

for HDD, dead-reckoning GPS backup)

? Motion detection for portable product power saving

(Auto-SLEEP and Auto-WAKE for cell phone, PDA, GPS, gaming)

? Shock and vibration monitoring

(mechatronic compensation, shipping and warranty usage logging)

? User interface

(menu scrolling by orientation change, tap detection for button replacement)