Bosch BMA400 Instruction Manual

Preliminary Data Sheet
BMA400
Digital, triaxial acceleration sensor
Preliminary Data Sheet BMA400
Part number(s)
0 273 141 xyz
Document revision
0.1
Release date
03 November 2017
Document number
BST-BMA400-DS000-00
Notes
Specifications are preliminary and subject to change without notice.
Product photos and pictures are for illustration purposes only and may
differ from the real product’s appearance.
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
BMA400
12 bit, digital, triaxial acceleration sensor with smart on-chip motion and position-triggered interrupt
features.
Key features
Small package size LGA package (12 pins), footprint 2mm x 2mm,
height 0.95 mm
Ultra-low power Low current consumption of data acquisition
without compromising on performance
(< 14 µA with highest performance)
Programmable functionality Acceleration ranges ±2g/±4g/±8g/±16g
Low-pass filter bandwidths = 0.48*ODR
up to a max. output data read out of 800Hz
On-chip FIFO Integrated FIFO on sensor with 1 kb
On-chip interrupt features Auto-low power/Auto wakeup
Activity/In-activit
Step Counter (4µA)
Activity Recognition (Walking, Running, Standing still)
Orientation detection
Tap/double tap
Digital interface SPI (4-wire, 3-wire), I²C, 2 interrupt pins
VDDIO voltage range: 1.2V to 3.6V
RoHS compliant, halogen-free
Typical applications
Step Counting with ultra-low current consumption for extensive battery lifetime
Advanced system power management for mobile applications and (smart) watches
Fitness applications / Activity Tracking
Tap / double tap sensing
Drop detection for warranty logging
Window/door measurements for climate control and alarm systems
IoT applications powered by coin cell driven batteries, requiring <1uA and auto-wakeup
functionality
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
Table of contents
Contents
1. SPECIFICATION.............................................................................................................................8
2. ABSOLUTE MAXIMUM RATINGS ..............................................................................................10
3. QUICK START GUIDE .................................................................................................................11
Note about using the BMA400:................................................................................................. 11
First application setup examples algorithms: ............................................................................ 11
4. FUNCTIONAL DESCRIPTION .....................................................................................................17
4.1. SUPPLY VOLTAGE AND POWER MANAGEMENT ......................................................................18
4.2. POWER MODES –PERFORMANCE MODES .............................................................................19
Wake-up Interrupt / Auto wake-up............................................................................................. 22
Auto low-power mode............................................................................................................... 26
4.3. SENSOR DATA ....................................................................................................................28
Acceleration Data ..................................................................................................................... 28
Filter Configuration ................................................................................................................... 28
G-range selection ..................................................................................................................... 29
Data Ready Interrupt ................................................................................................................ 29
Temperature Sensor ................................................................................................................. 29
Sensor Time ............................................................................................................................. 30
4.4. FIFO..................................................................................................................................31
FIFO description ....................................................................................................................... 31
FIFO input data......................................................................................................................... 31
FIFO read out ........................................................................................................................... 32
FIFO overflow behavior ............................................................................................................ 32
Frames ..................................................................................................................................... 33
Under-read ............................................................................................................................... 36
Partial frame read ..................................................................................................................... 36
Over-read ................................................................................................................................. 36
Reading nearly-empty FIFO...................................................................................................... 36
FIFO flushing............................................................................................................................ 37
FIFO watermark interrupt.......................................................................................................... 37
FIFO full interrupt...................................................................................................................... 39
4.5. GENERAL INTERRUPT PIN CONFIGURATION ...........................................................................40
Interrupt Pin Mapping ............................................................................................................... 40
Interrupt latching....................................................................................................................... 40
Interrupt behavior during power mode switching....................................................................... 41
Electrical Interrupt Pin Behavior................................................................................................ 42
4.6. INTERRUPT FEATURES.........................................................................................................43
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
Interrupt pin mapping, interrupt status ...................................................................................... 43
Generic Interrupt 1 and 2.......................................................................................................... 44
Step Detector / Step Counter.................................................................................................... 47
Activity changed interrupt ......................................................................................................... 48
Tap Sensing Interrupt................................................................................................................ 49
Interrupt engine overrun ........................................................................................................... 50
Orientation change interrupt ..................................................................................................... 51
4.7. SENSOR SELF-TEST ............................................................................................................54
4.8. SOFT-RESET.......................................................................................................................55
5. REGISTER DESCRIPTION ..........................................................................................................56
5.1. REGISTER MAP ...................................................................................................................56
Register (0x00) CHIPID ............................................................................................................ 59
Register (0x02) ERR_REG....................................................................................................... 60
Register (0x03) STATUS........................................................................................................... 60
Register (0x04) ACC_X_LSB.................................................................................................... 61
Register (0x05) ACC_X_MSB................................................................................................... 62
Register (0x06) ACC_Y_LSB.................................................................................................... 62
Register (0x07) ACC_Y_MSB................................................................................................... 63
Register (0x08) ACC_Z_LSB .................................................................................................... 63
Register (0x09) ACC_Z_MSB................................................................................................... 64
Register (0x0A) SENSOR_TIME0 ............................................................................................ 64
Register (0x0B) SENSOR_TIME1 ............................................................................................ 65
Register (0x0C) SENSOR_TIME2 ............................................................................................ 65
Register (0x0D) EVENT............................................................................................................ 66
Register (0x0E) INT_STAT0 ..................................................................................................... 66
Register (0x0F) INT_STAT1...................................................................................................... 67
Register (0x10) INT_STAT2...................................................................................................... 68
Register (0x11) TEMP_DATA.................................................................................................... 68
Register (0x12) FIFO_LENGTH0.............................................................................................. 69
Register (0x13) FIFO_LENGTH1.............................................................................................. 69
Register (0x14) FIFO_DATA ..................................................................................................... 70
Register (0x15) STEP_CNT_0.................................................................................................. 70
Register (0x16) STEP_CNT_1.................................................................................................. 71
Register (0x17) STEP_CNT_2.................................................................................................. 71
Register (0x18) STEP_STAT .................................................................................................... 72
Register (0x19) ACC_CONFIG0 ............................................................................................... 72
Register (0x1A) ACC_CONFIG1............................................................................................... 73
Register (0x1B) ACC_CONFIG2............................................................................................... 74
Register (0x1F) INT_CONFIG0 ................................................................................................ 74
Register (0x20) INT_CONFIG1................................................................................................. 75
Register (0x21) INT1_MAP....................................................................................................... 75
Register (0x22) INT2_MAP....................................................................................................... 76
Register (0x23) INT12_MAP..................................................................................................... 77
Register (0x24) INT12_IO_CTRL ............................................................................................. 78
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
Register (0x26) FIFO_CONFIG0 .............................................................................................. 79
Register (0x27) FIFO_CONFIG1 .............................................................................................. 80
Register (0x28) FIFO_CONFIG2 .............................................................................................. 80
Register (0x29) FIFO_PWR_CONFIG ...................................................................................... 81
Register (0x2A) AUTOLOWPOW_0.......................................................................................... 81
Register (0x2B) AUTOLOWPOW_1.......................................................................................... 82
Register (0x2C) AUTOWAKEUP_0........................................................................................... 83
Register (0x2D) AUTOWAKEUP_1........................................................................................... 83
Register (0x2F) WKUP_INT_CONFIG0.................................................................................... 84
Register (0x30) WKUP_INT_CONFIG1 .................................................................................... 85
Register (0x31) WKUP_INT_CONFIG2 .................................................................................... 85
Register (0x32) WKUP_INT_CONFIG3 .................................................................................... 86
Register (0x33) WKUP_INT_CONFIG4 .................................................................................... 86
Register (0x35) ORIENTCH_CONFIG0.................................................................................... 87
Register (0x36) ORIENTCH_CONFIG1.................................................................................... 88
Register (0x37) ORIENTCH_CONFIG2.................................................................................... 88
Register (0x38) ORIENTCH_CONFIG3.................................................................................... 89
Register (0x39) ORIENTCH_CONFIG4.................................................................................... 89
Register (0x3A) ORIENTCH_CONFIG5 ................................................................................... 90
Register (0x3B) ORIENTCH_CONFIG6 ................................................................................... 90
Register (0x3C) ORIENTCH_CONFIG7 ................................................................................... 91
Register (0x3D) ORIENTCH_CONFIG8 ................................................................................... 91
Register (0x3E) ORIENTCH_CONFIG9 ................................................................................... 92
Register (0x3F) GEN1INT_CONFIG0....................................................................................... 92
Register (0x40) GEN1INT_CONFIG1 ....................................................................................... 93
Register (0x41) GEN1INT_CONFIG2 ....................................................................................... 94
Register (0x42) GEN1INT_CONFIG3 ....................................................................................... 94
Register (0x43) GEN1INT_CONFIG31 ..................................................................................... 95
Register (0x44) GEN1INT_CONFIG4 ....................................................................................... 95
Register (0x45) GEN1INT_CONFIG5 ....................................................................................... 96
Register (0x46) GEN1INT_CONFIG6 ....................................................................................... 96
Register (0x47) GEN1INT_CONFIG7 ....................................................................................... 97
Register (0x48) GEN1INT_CONFIG8 ....................................................................................... 97
Register (0x49) GEN1INT_CONFIG9 ....................................................................................... 98
Register (0x4A) GEN2INT_CONFIG0....................................................................................... 98
Register (0x4B) GEN2INT_CONFIG1....................................................................................... 99
Register (0x4C) GEN2INT_CONFIG2 .................................................................................... 100
Register (0x4D) GEN2INT_CONFIG3 .................................................................................... 100
Register (0x4E) GEN2INT_CONFIG31................................................................................... 101
Register (0x4F) GEN2INT_CONFIG4..................................................................................... 101
Register (0x50) GEN2INT_CONFIG5 ..................................................................................... 102
Register (0x51) GEN2INT_CONFIG6 ..................................................................................... 102
Register (0x52) GEN2INT_CONFIG7 ..................................................................................... 103
Register (0x53) GEN2INT_CONFIG8 ..................................................................................... 103
Register (0x54) GEN2INT_CONFIG9 ..................................................................................... 104
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
Register (0x55) ACTCH_CONFIG0 ........................................................................................ 104
Register (0x56) ACTCH_CONFIG1 ........................................................................................ 105
Register (0x57) TAP_CONFIG................................................................................................ 106
Register (0x58) TAP_CONFIG1.............................................................................................. 106
Register (0x59) STEP_COUNTER_CONFIG0........................................................................ 108
Register (0x5A) STEP_COUNTER_CONFIG1 ....................................................................... 108
Register (0x5B) STEP_COUNTER_CONFIG2 ....................................................................... 109
Register (0x5C) STEP_COUNTER_CONFIG3 ....................................................................... 109
Register (0x5D) STEP_COUNTER_CONFIG4 ....................................................................... 110
Register (0x5E) STEP_COUNTER_CONFIG5 ....................................................................... 110
Register (0x5F) STEP_COUNTER_CONFIG6 ........................................................................111
Register (0x60) STEP_COUNTER_CONFIG7.........................................................................111
Register (0x61) STEP_COUNTER_CONFIG8........................................................................ 112
Register (0x62) STEP_COUNTER_CONFIG9........................................................................ 112
Register (0x63) STEP_COUNTER_CONFIG10...................................................................... 113
Register (0x64) STEP_COUNTER_CONFIG11 ...................................................................... 113
Register (0x65) STEP_COUNTER_CONFIG12...................................................................... 114
Register (0x66) STEP_COUNTER_CONFIG13...................................................................... 114
Register (0x67) STEP_COUNTER_CONFIG14...................................................................... 115
Register (0x68) STEP_COUNTER_CONFIG15...................................................................... 115
Register (0x69) STEP_COUNTER_CONFIG16...................................................................... 116
Register (0x6A) STEP_COUNTER_CONFIG17 ..................................................................... 116
Register (0x6B) STEP_COUNTER_CONFIG18 ..................................................................... 117
Register (0x6C) STEP_COUNTER_CONFIG19 ..................................................................... 117
Register (0x6D) STEP_COUNTER_CONFIG20 ..................................................................... 118
Register (0x6E) STEP_COUNTER_CONFIG21 ..................................................................... 118
Register (0x6F) STEP_COUNTER_CONFIG22...................................................................... 119
Register (0x70) STEP_COUNTER_CONFIG23...................................................................... 119
Register (0x71) STEP_COUNTER_CONFIG24...................................................................... 120
Register (0x7C) IF_CONF ...................................................................................................... 120
Register (0x7D) SELF_TEST.................................................................................................. 121
Register (0x7E) CMD.............................................................................................................. 122
6. DIGITAL INTERFACES..............................................................................................................123
6.1. INTERFACE .......................................................................................................................123
6.2. INTERFACE I2C/SPI PROTOCOL SELECTION .......................................................................124
6.3. SPI INTERFACE AND PROTOCOL .........................................................................................124
6.4. PRIMARY I2C INTERFACE...................................................................................................129
I²C read access: ..................................................................................................................... 131
7. PIN-OUT AND CONNECTION DIAGRAMS ..............................................................................133
7.1. PIN-OUT ...........................................................................................................................133
7.2. CONNECTION DIAGRAMS ...................................................................................................134
SPI ......................................................................................................................................... 134
I2C.......................................................................................................................................... 135
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
8. PACKAGE...................................................................................................................................136
8.1. PACKAGE OUTLINE DIMENSIONS .........................................................................................136
8.2. SENSING AXIS ORIENTATION...............................................................................................137
8.3. LANDING PATTERN RECOMMENDATION................................................................................139
8.4. MARKING ..........................................................................................................................140
8.5. SOLDERING GUIDELINES ....................................................................................................141
8.6. HANDLING INSTRUCTIONS ..................................................................................................142
8.7. ENVIRONMENTAL SAFETY...................................................................................................143
Halogen content ..................................................................................................................... 143
Internal package structure ...................................................................................................... 143
9. LEGAL DISCLAIMER.................................................................................................................144
9.1. ENGINEERING SAMPLES.........................................................................................................144
9.2. PRODUCT USE ..........................................................................................................................144
9.3. APPLICATION EXAMPLES AND HINTS..................................................................................144
10. DOCUMENT HISTORY AND MODIFICATION..........................................................................145
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
1. Specification
Unless stated otherwise, the given values are over lifetime, operating temperature and voltage ranges.
Minimum/maximum values are ±3.
Parameter Specification
Parameter
Symbol
Condition
Min
Typ
Max
Acceleration
Range
gFS2g
±2
g
gFS4g
±4
g
gFS8g
±8
g
gFS16g
±16
g
Supply Voltage
Internal
Domains
VDD
1.72
1.8
3.6
V
Supply Voltage
I/O Domain
VDDIO
1.2
1.8
3.6
V
Voltage Input
Low Level
VIL
SPI & I²C
0.3VDDIO
Voltage Input
High Level
VIH
SPI & I²C
0.7VDDIO
Voltage Output
Low Level
VOL
VDDIO=1.8V,
IOL=3mA, SPI
0.2VDDIO
VDDIO=1.2V,
IOL=3mA, SPI
0.23VDDIO
Voltage Output
High Level
VOH
VDDIO=1.8V,
IOH=3mA, SPI
0.8VDDIO
VDDIO=1.2V,
IOH=3mA, SPI
0.62VDDIO
Total Supply
Current in
Normal mode
IDD
Nominal VDD and
VDDIO, 25°C,
OSR=3
14
µA
Total Supply
Current in
Sleep Mode
IDDsum
Nominal VDD and
VDDIO, 25°C
200
nA
Total Supply
Current in
Low-power
Mode
IDDlp1
Nominal VDD and
VDDIO, 25°C
25 Hz ODR
OSR=0
800
nA
Wake-Up Time
tw_up
From sleep to
normal mode
2/ODR
Power-Up Time
ts_up
Starting the device
to sleep mode
1
ms
Operating
Temperature
TA
-40
+85
°C
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
OUTPUT SIGNAL
Parameter
Symbol
Condition
Min
Typ
Max
Units
Sensitivity
S2g
gFS2g, TA=25°C
1024
LSB/g
S4g
gFS4g, TA=25°C
512
LSB/g
S8g
gFS8g, TA=25°C
256
LSB/g
S16g
gFS16g, TA=25°C
128
LSB/g
Sensitivity
Temperature
Drift
TCS
0.02
%/K
Zero-g Offset
Off
Nominal VDD and
VDDIO, 25°C, gFS4g
Over life-time
80
mg
Zero-g Offset
Temperature
Drift
TCO
1
mg/K
Output Data
Rate
ODRNORM
Normal mode
12.5
800
Hz
Bandwidth
BWnorm
3dB cutoff
frequency of the
accelerometer is
selectable
0.24*ODR
0.48*ODR
Hz
Output Data
Rate
ODRLPM
Low-power mode
25
Hz
Nonlinearity
NL
Nominal VDD and
VDDIO, 25°C, gFS4g
0.5
%FS
Output Noise
Density
nrms
Typical VDD and
VDDIO, normal
mode, OSR=3 (high
performance) 25°C,
4g
220
µg/Hz
MECHANICAL CHARACTERISTICS
Parameter
Symbol
Condition
Min
Typ
Max
Units
Cross Axis
Sensitivity
S
relative contribution
between any two of
the three axes
2
%
Alignment Error
EA
relative to package
outline
0.5
°
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
2. Absolute maximum ratings
Absolute maximum ratings
Parameter
Condition
Min
Max
Units
Voltage at Supply Pin
VDD Pin
-0.3
3.6
V
VDDIO Pin
-0.3
3.6
V
Voltage at any Logic Pin
Non-Supply Pin
-0.3
VDDIO+0.3, <4
V
Passive Storage Temp. Range
≤ 65% rel. H.
-50
+150
°C
Mechanical Shock
Duration ≤ 200µs
10,000
g
Duration ≤ 1.0ms
2,000
g
Free fall
onto hard surfaces
1.8
m
ESD
HBM, at any Pin
2
kV
CDM
500
V
MM
200
V
Note:
Stress above these limits may cause damage to the device. Exceeding the specified electrical limits
may affect the device reliability or cause malfunction.
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
3. Quick Start Guide
The purpose of this chapter is to help developers who want to start working with the BMA400 by giving
you some very basic hands-on application examples to get started.
Note about using the BMA400:
The communication between application processor AP and BMA400 will happen either over
I2C or SPI interface. For more information about the interfaces, read the related chapter 6.
Digital Interfaces.
For information about connecting the BMA400 to the host (AP), read the related chapter 7
where you find Pin-out and Connection Diagrams.
First application setup examples algorithms:
After correct power up by setting the correct voltage to the power pins, the BMA400 enters
automatically into the Power On Reset (POR) sequence, also called boot sequence. After having
completed boot, the BMA400 enters sleep mode where it consumes 200nA. No data conversions
happen in this phase, but register read-out and write is possible. Communication can start in I2C or
SPI mode. The BMA400 automatically detects which format is used. When SPI format is used, the
BMA400 switches to SPI4 mode and remains in this mode until reset. The switching to SPI requires
to send the very first SPI packet twice: the first packet will be ignored by the BMA400.
If SPI3 communication is desired, a write to register IF_CONF ( write_reg(IF_CONF, 0x01) ) switches
the communication protocol to SPI3.
In order to properly make use of the BMA400, certain steps from host processor side are needed. The
most typical operations will be explained in the following application examples in form of flow-diagrams.
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
1. Example 1: Testing communication with the BMA400, switch to SPI communication,
state data conversion, enable data ready interrupt and map it to INT1 pin
-reading chip id (checking correct communication) using I2C or SPI
power
up
chipid = read_reg(0x00)
chipid = 0x90 ?
communication: OK communication: ERROR
Yes No
I2C
SPI/I2C
I2C Sleep
mode End
End
power
up
dummy = read_reg(0x00)
chipid = 0x90 ?
communication: OK communication: ERROR
Yes No
chipid = read_reg(0x00)
SPI/I2C
SPI
SPI4
SPI4 sleep
mode
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BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
–switching from sleep to normal mode, then SPI3 mode, then enable data ready interrupt and
map to pin int1
sleep
mode
Switch from sleep mode to
normal mode: ACC_CONFIG0
write_reg(addr=0x19,val=0x02)
wait(1500us)
write_reg(addr=0x21,val=0x80)
write_reg(addr=0x1A,val=0x30)range=2g, osr=3 (high perf), acc_odr=100Hz:
ACC_CONFIG1
write_reg(addr=0x1B,val=0xE4) Enable X,Y,Zaxis, use acc_filt2
(100Hz fixed) as data source:
ACC_CONFIG2
write_reg(addr=0x1F,val=0x80)Enable data ready interrupt:
INT_CONFIG0
Map dataready interrupt to
INT1 pin: INT_CONFIG1
write_reg(addr=0x7C,val=0x01)Switch from SPI4 mode to
SPI3 mode: IF_CONF
SPI4
SPI4
SPI4
SPI3
SPI3
SPI3
SPI3
Normal mode
data conv enabled
data ready int toint1
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BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
-checking communication via chipid, check power mode, read acceleration data if not in sleep
mode
unknown
mode
STATUS.power_mode
chipid = read_reg(0x00)
chip_ID = 0x90 ? EndNO
power_mode = (read_reg(0x03)>>1) & 0x03
power_mode = 0x00 ?YES sleepmode, no accel
data available
power_mode = 0x01 ?YES low power mode
NO
acc_data = read_reg_burst(0x08,6)
X = acc_data(0) +256*acc_data(1)
if ( X>2047 ) X=X-4096
6 byte Burst read
X,Y,Zdata
registers
in normal orlow power
mode, calculate X data
normal mode
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
1. Example 3: Testing interrupt engine of BMA400 (example: inactivity interrupt)
a. -performing reconfiguration sequence (interrupt feature: significant motion)
Normal
mode
all interrupts only available in
normal mode except wake-up,
data ready
set threshold LSBs
map gen1 interrupt to int1 pin
interrupts are non-latched: if
interrupt reason vanishes, int1
is deasserted
Int1 pin interrupt = HIGH active
Enable X,Y,Zaxis, data
source = acc_filt2 (fixed
100Hz), update
reference every time,
hysteresis= 48mg
Configure gen1 interrupt to
inactivity (criterion=0), AND
combinationof all axes
write_reg(addr=0x21,0x04)
write_reg(addr=0x20,0x00)
write_reg(addr=0x24,0x02)
write_reg(addr=0x3F,0xFA)
write_reg(addr=0x40,0x01)
write_reg(addr=0x41,0xff)
write_reg(addr=0x43,0x0f) set min. duration LSBs
to 15 ODR ticks
write_reg(addr=0x1F,0x04)Enable gen1 interrupt in normal
mode, mapped to int1 pin and
configured as inactivity interrupt with
15ODR ticks minimum duration
Shake sensor, int1 shouldremain
LOW.
Put sensor on table and wait for the
interrupt pin int1 to get HIGH
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
Further steps:
The BMA400 has many more capabilities that are described in this document and include FIFO,
power saving modes, synchronization capabilities with host processor, data synchronization, many
interrupts generation and more features like step counter, etc.
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
4. Functional Description
Block Diagram
Interrupt engine
C2V,
ADC
MEMS DIGITAL SIGNAL
FILTERING
DIGITAL
INTERFACE
SENSOR DATA
AND SENSORTIME
REGISTER
FIFO ENGINE
SPI / I2C
INT1, INT2
acc_odr
acc_filt1
acc_filt2
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
4.1. Supply Voltage and Power Management
BMA400 has two distinct power supply pins:
VDD is the main power supply.
VDDIO is a separate power supply pin used for supplying power for the digital communication
interface.
There are no limitations with respect to the voltage level applied to the VDD and VDDIO pins, as long
as it lies within the respective operating range. Furthermore, the device can be completely switched
off (VDD=0V) while keeping the VDDIO supply within operating range or vice versa. However if the
VDDIO supply is switched off, all interface pins (CSB, SDX, SCX) must be kept close to GNDIO
potential. No constraints exist for the minimum slew-rate of the voltage applied to the VDD and VDDIO
pins.
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Preliminary Data Sheet
BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
4.2. Power Modes – performance modes
The power mode and all major settings affecting performance, current consumption, noise and output
data rate are controlled in registers ACC_CONFIG0, ACC_CONFIG1 and ACC_CONFIG2.
The BMA400 knows 3 power modes: sleep mode, low-power mode and normal mode.
In sleep mode, current consumption is below 300nA, and data conversions are stopped as well as
sensortime functionality.
In low power mode, data conversion runs with a fixed rate of 25Hz, and performance can be
controlled via ACC_CONFIG0.osr_lp setting. Current consumption ranges between 800 nA and 1100
nA depending on performance setting. The low power mode should be mainly used in combination
with activity detection as self wake-up mode. In this use case, 800 nA are sufficient.
In normal mode, output data rates between 800Hz and 12.5Hz can be configured using the registers
ACC_CONFIG1.acc_odr and ACC_CONFIG1.osr. The noise density performance of the BMA400 is
mainly determined by ACC_CONFIG1.osr. The RMS noise and the resulting current consumption of
the device is influenced by ACC_CONFIG1.acc_odr and ACC_CONFIG1.osr.
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BMA400
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Confidential
BST-BMA400-DS000-00 | Version 0.1 | November 2017 Bosch Sensortec
©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.
In all 3 power modes both register contents and FIFO contents are retained. FIFO readout can be
done in normal mode only. The FIFO is written only in normal mode.
ACC_CONFIG0.
power_mode<1:0>
Description
Details
b00
b11
Sleep mode
(default state after power-up and
after reset)
I(VDD)< 300nA typ
No sensortime, no FIFO read, no data
conversions. Register and FIFO content
retained, registers readable and writeable
b01
Low-power mode
I(VDD)< 1.1uA typ
Data conversion at 25Hz fixed, noise
performance and current consumption tunable
by ACC_CONFIG0.osr_lp setting
wake-up interrupt to switch into normal mode
No FIFO read/write
b10
Normal mode
I(VDD)< 14 uA typ
Data conversion configurable between 800Hz
and 12.5Hz, noise performance and current
consumption tunable by ACC_CONFIG1.osr
FIFO read and write
All interrupts available
Auto-low-power function/interrupt using generic
interrupt 1 to switch automatically into low-power
mode
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