CMA3000-D0X Datasheet, PDF (32/35 Pages) VTI technologies – 3-axis accelerometer

CMA3000-D0X Series
9.1.2 Acceleration reading without interrupts
Acceleration data reading without interrupts can be used in all operation modes. Acceleration data
is read out faster than CMA3000 can updates the acceleration output registers. When two identical
XYZ acceleration values are received, the data is considered valid. The maximum data reading
periods in different operation modes are presented below in Table 13.
Table 13. CMA3000-D01 maximum reading periods when interrupts are not detected.
Output data rate
CMA3000-D01, MODE bits x10
ODR: 400Hz
CMA3000-D01, MODE bits x01
ODR: 100Hz
CMA3000-D01, MODE bits 011
ODR: 40Hz
CMA3000-D01, MODE bits 100
ODR: 10Hz
ODR = Output Data Rate
Maximum reading period
for 3 samples, T_r
2.4 ms
9.9 ms
24.0 ms
90.0 ms
Internal acceleration
register update
These two acceleration readings result identical
acceleration values → This result is accepted
Internal acceleration
register update
Acceleration reading
→ corrupted
Acceleration reading
Acceleration reading
Acceleration data reading period for 3 samples, T_r
Figure 25. Interrupt based CMA3000 acceleration data read timing.
Acceleration reading
→ corrupted
9.2 Leakage current when VDD - DVIO > 0.3 V
Due to design issue a switch will leak some current, if the VDD will be approx 300 mV higher than
DVIO. Typical leakage currents are according to the Table 14 below.
Table 14 CMA3000-D0X typical DVIO leakage current when VDD-DVIO>0.3V.
VDD/DVIO [V]
2.5 / 1.7
3.6 / 1.7
Leakage current [µA]
25
100
VTI Technologies Oy
www.vti.fi
Doc.Nr. 8281000.12
32/ 35
Rev. 0.12