BMA145 Bosch Sensortec, BMA145 Datasheet - Page 11

• Manufacturer Part Number: BMA145
• Description: 3-AXIS ACCELEROMETER ANALOG I/F
• Manufacturer: Bosch Sensortec

Specifications of BMA145

• Axis: X, Y, Z
• Acceleration Range: ±4g
• Sensitivity: 300mV/g
• Voltage - Supply: 1.8 V ~ 3.5 V
• Output Type: Analog
• Bandwidth: 1.5kHz
• Interface: Parallel
• Mounting Type: Surface Mount
• Package / Case: 16-LGA
• For Use With: 828-1011 - BMA145 DAUGHTERCARD FOR DEV KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 828-1002-2

IMPORTANT NOTE: SEL.0 and SEL.1 transitions must be synchronous within a 20ns tolerance
to avoid the ASIC to switch to an unwanted state at transitions (valid for the four possible
transitions where the two signals SEL.0 and SEL.1 have to change simultaneously). See also
the figure given below.
4.4
By selecting the operation mode to “Normal” all 3 axis provide acceleration measurement
signals simultaneously on the Ax, Ay and Az pins according to the following equation.
Ax, Ay and Az are the vector components of the acting acceleration. According to chapter 1 the
sensitivity in the ±4g range corresponds to VDD/10 given in V/g. This means, the maximal
default acceleration range is ±4g.
4.5
The sensor features an on-chip self-test which can be activated by using the corresponding self
test input pin. The self test is realized by a physical deflection of the seismic mass due to an
electrostatic force. Thus, it provides contact and functional testing of the complete signal
evaluation path including the MEMS acceleration-sensing element and the evaluation ASIC.
The self test is activated by setting the self test activation input pin to logic 1. The test acts on all
three channels simultaneously. The typical change in output will be a static offset of
approximately +0.65g for x-, y- and for x-axis (nominal value). For the ±4g acceleration range
this corresponds to an nominal output signal delta of ∆Uout
Rev. 1.1
© 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.
A
X
=
Analog output on Ax, Ay and Az
Self test
⎛
⎜
⎝
V
2
DD
+
S
⋅
a
X
⎞
⎟
⎠
Triaxial, analog acceleration sensor
A
Y
=
⎛
⎜
⎝
V
DD
2
Data sheet
Page 11
BMA145
+
S
⋅
a
Y
⎞
⎟
⎠
nom
[v] = (Vdd [v] / 10) x 0.65 , to be
A
Z
=
⎛
⎜
⎝
V
2
DD
+
Bosch Sensortec
S
02 April 2008
⋅
a
Z
⎞
⎟
⎠