BMA145
BMA145
Data sheet
Triaxial, analog acceleration sensor
Data sheet
Bosch Sensortec
BMA145 Data sheet
Device order code
Package type
Data sheet revision
Release date
Document number
Notes
Rev. 1.3
0 273 141 027
16-pin LGA
1.3
11 February 2010
BST-BMA145-DS000-03
Specifications are subject to change without notice.
Page 1 proprietary information
11 February 2010
Product /photos and pictures are for illustration purposes only and may
differ
in the event of industrial property rights. We
© Bosch Sensortec GmbH reserves all rights even
from the real product’s appearance.
reserve all rights of disposal such
as copying and passing on to third parties. BOSCH and the
information – not
trademarks of
for publication.
Germany.
Proprietary
symbol are registered
intended
Robert Bosch GmbH,
Note: Specifications within this document are subject to change without notice.
BMA145
Data sheet
Bosch Sensortec
BMA145 – triaxial, analog
4g
analog accelerometer
Key features
-
-
-
-
Triaxial, ±4g full scale accelerometer
Standard LGA package with 4mm x 4mm footprint, 0.9mm height
2 operation modes: Stand-by- and normal mode
Ultra-low power consumption:
- 200μA in operation mode
- 0.7μA in stand-by mode
Only 1 msec. turn-on time form stand-by mode to operation mode
Analog output signals: 3 parallel (X, Y, Z) plus 1 serial (multiplexed X, Y, Z)
Internal 1.5kHz 1
st
-order low-pass analog filter
Customizable corner frequency
On-chip gain and offset compensation, calibrated on factory level.
Trigger-able self-test capability of MEMS sensor element and ASIC
RoHS compliant, halogen-free
Based on automotive-proven Bosch MEMS wafer-fabrication technology & processes
-
-
-
-
-
-
-
-
Typical applications
Tilt, motion and vibration sensing in
-
Gaming
-
Virtual reality
-
Sports- and life style wear
-
Cell-phones
-
Handhelds, PDAs, PNDs
-
Healthcare
-
Patient monitoring
-
Navigation
-
Electronic compass compensation
-
Computer peripherals
-
Man-machine interfaces
Rev. 1.3
Page 2 / proprietary information
11 February 2010
© 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.
BMA145
Data sheet
Bosch Sensortec
THE BMA145 IN GENERAL
The BMA145 is a triaxial low-g acceleration sensor for consumer market applications, available
in a standard SMD LGA package with a footprint of 4mm x 4mm and a height of only 0.9mm. It
allows measurements of static as well as dynamic accelerations. Due to its three perpendicular
axes it gives the absolute orientation in a gravity field and enables free-fall detection. As all
other Bosch inertial sensors, the BMA145 is a two-chip arrangement, which combines an
application-specific integrated circuit (ASIC) with a three-channel silicon accelerometer, to form
a true micro electro mechanical system (MEMS).
The ASIC evaluates the output of the acceleration-sensing element, corresponding to the
differential capacitance principle. The underlying MEMS technology processes have proven
their capability according to the strictest automotive standards in more than 100 million Bosch
inertial sensors a year so far.
The BMA145 provides 3 parallel analog output signals in a
4g
acceleration range. All
acceleration signals are permanently available on 3 independent analog pads through 33kΩ
resistors on each pad. This allows the user defining the signal bandwidth by the mean of
external capacitors connected between each channel output and ground. Additional to the
parallel X, Y and Z output signals there is the option to multiplex any axis to 1 supplementary
output pin in a freely customized manner. This allows the user to connect the triaxial BMA145 to
an economical single channel AD converter without loss of axis information.
For each axis, an independent analog 1.5 kHz 1
st
-order low-pass filter is included to provide
preconditioning of the measured acceleration signal. The corner frequency of this filter can
easily be customized. Additional signal preconditioning steps are performed by a digital to
analog converter for offset and gain correction purposes with a subsequent signal amplification.
The output signals are ratiometric. In the ±4g acceleration range the sensor is offering a
sensitivity of 300mV/g at 3.0 V supply voltage (V
DD
/ 10) and 175μg/√Hz as a typical noise level.
The typical current consumption is 200μA in operation mode. Furthermore, the sensor can be
switched into a standby mode via supplementary selection pins. In standby mode the sensor
module features an ultra low current consumption of typically 0.7
μA.
The return from standby
mode to full performance conditions is performed in less than 1ms wake up time.
The BMA145 sensor module is ready to use due to test and calibration at factory level. All
calibration parameters, e.g. for offset and sensitivity, are stored in an internal EEPROM. The
sensor also features full self-test capability for all three axes. It is activated via a single self test
activation pin which results in a physical deflection of the seismic mass in the sensing element
due to electrostatic forces. Thus, it provides full contact and functional testing of the complete
signal evaluation path including the MEMS acceleration-sensing element and the evaluation
ASIC.
Rev. 1.3
Page 3 / proprietary information
11 February 2010
© 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.
BMA145
Data sheet
Bosch Sensortec
C
ONTENT
1
2
3
SPECIFICATION................................................................................................................................... 6
ABSOLUTE MAXIMUM RATINGS........................................................................................................8
BMA145 FEATURES............................................................................................................................ 9
3.1
G
ENERAL DESCRIPTION
.................................................................................................................. 9
3.1.1
MEMS element ....................................................................................................................... 9
3.1.2
ASIC........................................................................................................................................ 9
3.2
C
HANNEL MULTIPLEXER
................................................................................................................ 10
4
OPERATION ....................................................................................................................................... 11
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
P
OWER
-
ON
-
RESET AND POWER
-
UP SEQUENCE
............................................................................... 11
O
PERATION MODE SELECTION
....................................................................................................... 11
C
HANNEL MULTIPLEXER OUTPUT SELECTION
.................................................................................. 11
A
NALOG OUTPUT ON
A
X
, A
Y AND
A
Z
.............................................................................................. 12
S
ELF TEST
................................................................................................................................... 12
P
OLARITY OF THE ACCELERATION OUTPUT
..................................................................................... 14
P
IN CONFIGURATION
(
TOP VIEW
,
PADS NOT VISIBLE
)........................................................................ 15
C
ONNECTING DIAGRAM
................................................................................................................. 16
4.8.1
Full feature operation............................................................................................................ 16
4.8.2
Simple 3-channel operation.................................................................................................. 16
4.8.3
Customizing bandwidth and noise........................................................................................ 17
4.9
H
ANDLING INSTRUCTION
............................................................................................................... 17
5
PACKAGE .......................................................................................................................................... 18
5.1
5.2
5.3
O
UTLINE DIMENSIONS
................................................................................................................... 18
P
RINTED CIRCUIT BOARD
(PCB)
DESIGN
........................................................................................ 19
M
ARKING
.................................................................................................................................... 20
5.3.1
Mass production samples..................................................................................................... 20
5.3.2
Engineering samples ............................................................................................................ 20
5.4
M
OISTURE SENSITIVITY LEVEL AND SOLDERING
............................................................................... 21
5.5
T
APE AND REEL SPECIFICATION
..................................................................................................... 22
5.5.1
Orientation ............................................................................................................................ 23
5.6
R
O
HS
COMPLIANCY
..................................................................................................................... 24
5.7
5.8
H
ALOGEN CONTENT
..................................................................................................................... 24
N
OTE ON INTERNAL PACKAGE STRUCTURE
..................................................................................... 24
Rev. 1.3
Page 4 / proprietary information
11 February 2010
© 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.
BMA145
Data sheet
Bosch Sensortec
6
LEGAL DISCLAIMER......................................................................................................................... 25
6.1
6.2
6.3
E
NGINEERING SAMPLES
................................................................................................................ 25
P
RODUCT USE
............................................................................................................................. 25
A
PPLICATION EXAMPLES AND HINTS
............................................................................................... 25
7
DOCUMENT HISTORY AND MODIFICATION .................................................................................. 26
Rev. 1.3
Page 5 / proprietary information
11 February 2010
© 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.
京公网安备 11010802033920号
EEWORLD
