BMA150-0330SB0003 BOSCH, BMA150-0330SB0003 Datasheet - Page 52

• Manufacturer Part Number: BMA150-0330SB0003
• Description: Daughter Board
• Manufacturer: BOSCH

Specifications of BMA150-0330SB0003

• Silicon Manufacturer: Bosch
• Application Sub Type: Accelerometer - Three-Axis
• Kit Application Type: Sensing - Motion / Vibration / Shock
• Silicon Core Number: BMA150
• Kit Contents: Board

Figure 30: Explanation of freefall and high-g detection. Please see explanation within the text.
9.3 Any motion detection
The “any motion algorithm” can be used to detect changes of the acceleration. Thus it provides
a relative evaluation of the acceleration signals. The criterion is kind of a gradient threshold of
the acceleration over time. Thus one can distinguish between fast events with strong inertial
dynamic (e.g. shock), instant changes of force balance (e.g. drop, tumbling) and even slight
changes (e.g. touch of a mobile device).
Due to a high bandwidth and a fast response MEMS device the BMA150 is capable to detect
shock situations. The “any motion interrupt” or a high-g criterion setting can be used to give a
shock alert. The phase shift between onset of mechanical shock and interrupt output is defined
by the mechanical transfer function of the chassis and internal mounting interfaces (e.g. PDA
shell) and the data output rate of the sensor IC (currently 330µsec, 100µsec under
consideration).
See also section 3.2.9.
9.4 Alert Mode
Using the BMA150 it is possible to combine the “any motion criterion” with low-g and high-g
interrupt logic to improve the reaction time for e.g. free-fall identification.
See also sections 3.2.9 and 3.4.2.
Rev. 1.5
© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
high
low
|a|
INT
acceleration
High-g threshold
Freefall threshold
Triaxial, digital acceleration sensor
Evaluation duration
Data sheet
BMA150
Page 52
Hysteresis
Latched INT
Reset INT
time
Bosch Sensortec
30 May 2008