CMA3000-D0X Datasheet, PDF (6/35 Pages) VTI technologies – 3-axis accelerometer

CMA3000-D0X Series
1.2.4 Supported features
Supported features are listed in Table 1 below.
Table 1. CMA3000-D0X devices’ summary.
Features
Supply voltage
I/O voltage
Measuring range (selectable)
Resolution (2g /8g range)
Sensitivity (2g /8g range)
Motion detection
Free fall detection
Interface
Clock
CMA3000-D01
1.7 V – 3.6 V
1.7 V – 3.6 V
±2 g, ±8 g
17 mg / 67 mg
56 counts/g / 14 counts/g
User enabled
User enabled
SPI max 500 kHz, I²C fast mode 400 kHz
Internal
1.2.5 Operation modes
1.2.5.1 Power Down
In Power Down (PD) mode device's volatile register keep their contents and the current
consumption is minimized. Power down mode is the default mode after start up.
1.2.5.2
Measurement
In Measurement mode (Meas) the sensor offers acceleration information via the digital SPI/I²C
interface. Interrupt can be activated via INT-pin, when each xyz-acceleration sample is ready to be
read.
Measurement range and sample rate are user selectable according to Table 2. Measurement mode
can be activated by detected motion.
1.2.5.3 Motion Detection
Motion Detection (MD) mode is intended to be used to save system level power consumption. In
this mode, CMA3000-D0X activates the interrupt via the INT-pin when motion is detected. Motion
sensitivity level can be configured via the SPI or I²C bus. Moreover, duration of the motion to be
detected can be user defined. Once the interrupt has happened, the detected direction can be read
out from the corresponding status register.
Low sample rate (10 Hz) band-pass filtered acceleration information is available in MD mode. The
device can be configured to switch automatically into the measurement mode with highest
sampling rate after motion detection.
1.2.5.4 Free-Fall Detection
Free-Fall Detection (FFD) is intended to be used to save system resources. This feature activates
the interrupt via the INT-pin when free-fall is detected. Acceleration information is available when
the FFD is enabled.
1.2.6 Interrupt
The CMA3000 has a dedicated output pin (INT) to be used as the interrupt for the master
controller. Interrupt conditions can be activated and deactivated via the SPI or I²C bus. Once the
interrupt has happened, the interrupt source can be read out from the corresponding status
register.
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