ultra low-power high performance 3-axes “nano” accelerometer
Features
■ Wide supply voltage, 2.16 V to 3.6 V
■ Low voltage compatible IOs, 1.8 V
■ Ultra low-power mode consumption
down to 10 µA
■ ±2g/±4g/±8g dynamically selectable full-scale
2
■ I
C/SPI digital output interface
■ 16 bit data output
■ 2 independent programmable interrupt
generators for free-fall and motion detection
■ Sleep to wake-up function
■ 6D orientation detection
■ Embedded self-test
■ 10000 g high shock survivability
■ ECOPACK
®
RoHS and “Green” compliant (see
Section 8)
Applications
■ Motion activated functions
■ Free-fall detection
■ Intelligent power saving for handheld devices
■ Pedometer
■ Display orientation
■ Gaming and virtual reality input devices
■ Impact recognition and logging
■ Vibration monitoring and compensation
LGA 16
Description
The LIS331DLH is an ultra low-power high
performance three axes linear accelerometer
belonging to the “nano” family, with digital I
serial interface standard output.
The device features ultra low-power operational
modes that allow advanced power saving and
smart sleep to wake-up functions.
The LIS331DLH has dynamically user selectable
full scales of ±2g/±4g/±8g and it is capable of
measuring accelerations with output data rates
from 0.5 Hz to 1 kHz.
The self-test capability allows the user to check
the functioning of the sensor in the final
application.
The device may be configured to generate
interrupt signal by inertial wake-up/free-fall events
as well as by the position of the device itself.
Thresholds and timing of interrupt generators are
programmable by the end user on the fly.
The LIS331DLH is available in small thin plastic
land grid array package (LGA) and it is
guaranteed to operate over an extended
temperature range from -40 °C to +85 °C.
Table 3.Mechanical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted
SymbolParameterTest conditionsMin.Typ.
FS bit set to 00±2.0
FSMeasurement range
SoSensitivity
TCSo
Ty Of f
TCOff
Sensitivity change vs
temperature
Typical zeroaccuracy
Zero-
g level offset
(4),(5)
g level change vs
temperature
AnAcceleration noise densityFS bit set to 00218µ
Vst
Self-test
output change
TopOperating temperature range-40+85°C
WhProduct weight20mgram
1. The product is factory calibrated at 2.5 V. The operational power supply range is from 2.16 V to 3.6 V.
2. Typical specifications are not guaranteed
3. Verified by wafer level test and measurement of initial offset and sensitivity
4. Typical zero-g level offset value after MSL3 preconditioning
5. Offset can be eliminated by enabling the built-in high pass filter
6. The sign of “Self-test output change” is defined by CTRL_REG4 STsign bit (Table 28), for all axes.
Self-test output changes with the power supply. “Self-test output change” is defined as
7.
OUTPUT[LSb]
8. Output data reach 99% of final value after 1/ODR+ 1 ms when enabling self-test mode, due to device filtering
(CTRL_REG4 ST bit=1)
(3)
(6),(7),(8)
- OUTPUT[LSb]
FS bit set to 01±4.0
FS bit set to 11±8.0
FS bit set to 00
12 bit representation
FS bit set to 01
12 bit representation
FS bit set to 11
12 bit representation
0.911.1
1.822.2
3.53.94.3
FS bit set to 00±0.01%/°C
FS bit set to 00±20mg
Max delta from 25 °C±0.1m
FS bit set to 00
X axis
FS bit set to 00
Y axis
FS bit set to 00
Z axis
(CTRL_REG4 ST bit=0)
. 1LSb=4g/4096 at 12bit representation, ±2 g Full-scale
120300550LSb
120300550LSb
140350750LSb
(2)
(1)
Max.Unit
g
g/digit
m
g/°C
g/
Hz
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Mechanical and electrical specificationsLIS331DLH
2.2 Electrical characteristics
Table 4.Electrical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted
SymbolParameterTest conditionsMin.Typ.
(2)
(1)
Max.Unit
VddSupply voltage2.162.53.6V
Vdd_IOI/O pins supply voltage
Idd
IddLP
IddPdn
VIH
Current consumption
in normal mode
Current consumption
in low-power mode
Current consumption in
power-down mode
Digital high level input
voltage
(3)
1.71Vdd+0.1V
250µA
10µA
1µA
0.8*Vdd_IOV
VILDigital low level input voltage0.2*Vdd_IOV
VOHHigh level output voltage0.9*Vdd_IOV
VOLLow level output voltage0.1*Vdd_IOV
DR bit set to 0050
ODR
Output data rate
in normal mode
DR bit set to 01100
DR bit set to 10400
DR bit set to 111000
Hz
PM bit set to 0100.5
PM bit set to 0111
ODR
Output data rate
LP
in low-power mode
PM bit set to 1002
PM bit set to 1015
PM bit set to 11010
(5)
(4)
ODR/2Hz
ODR = 100 Hz1/ODR+1mss
BWSystem bandwidth
TonTurn-on time
TopOperating temperature range-40+85
1. The product is factory calibrated at 2.5 V. The operational power supply range is from 2.16 V to 3.6 V.
2. Typical specification are not guaranteed
3. It is possible to remove Vdd maintaining Vdd_IO without blocking the communication busses, in this condition the
measurement chain is powered off.
4. Refer to Table 20 for filter cut-off frequency
5. Time to obtain valid data after exiting power-down mode
Hz
°C
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LIS331DLHMechanical and electrical specifications
t
t
t
t
t
t
t
t
2.3 Communication interface characteristics
2.3.1 SPI - serial peripheral interface
Subject to general operating conditions for Vdd and Top.
Table 5.SPI slave timing values
(1)
Val u e
SymbolParameter
Unit
MinMax
tc(SPC)SPI clock cycle100ns
fc(SPC)SPI clock frequency10MHz
tsu(CS)CS setup time6
th(CS)CS hold time8
tsu(SI)SDI input setup time5
th(SI)SDI input hold time15
ns
tv(SO)SDO valid output time50
th(SO)SDO output hold time9
tdis(SO)SDO output disable time50
(2)
h(SI)
MSB OUT
c(SPC)
LSB IN
v(SO)
h(SO)
LSB OUT
Figure 3.SPI slave timing diagram
CS
(3)
su(CS)
SPC
(3)
su(SI)
(3)
SDI
(3)
SDO
1. Values are guaranteed at 10 MHz clock frequency for SPI with both 4 and 3 wires, based on characterization results, not
tested in production
MSB IN
2. Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both Input and output port
3. When no communication is on-going, data on CS, SPC, SDI and SDO are driven by internal pull-up resistors
h(CS)
(3)
(3)
(3)
dis(SO)
(3)
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Mechanical and electrical specificationsLIS331DLH
t
t
t
t
t
t
t
t
t
t
t
t
T
2.3.2 I2C - inter IC control interface
Subject to general operating conditions for Vdd and top.
Table 6.I2C slave timing values
SymbolParameter
I2C standard mode
(1)
I2C fast mode
MinMaxMinMax
(1)
Unit
f
(SCL)
t
w(SCLL)
t
w(SCLH)
t
su(SDA)
t
h(SDA)
t
r(SDA) tr(SCL)
t
f(SDA) tf(SCL)
t
h(ST)
t
su(SR)
t
su(SP)
t
w(SP:SR)
SCL clock frequency01000400KHz
SCL clock low time4.71.3
SCL clock high time4.00.6
SDA setup time250100ns
SDA data hold time0.013.450.010.9µs
SDA and SCL rise time1000
SDA and SCL fall time300
START condition hold time40.6
Repeated START condition
setup time
4.70.6
STOP condition setup time40.6
Bus free time between STOP
and START condition
4.71.3
1. Data based on standard I2C protocol requirement, not tested in production
2. Cb = total capacitance of one bus line, in pF
Figure 4.I
2
C Slave timing diagram
START
(a)
20 + 0.1C
20 + 0.1C
µs
(2)
b
2)
(
b
300
ns
300
µs
REPEATED
START
SDA
f(SDA)
r(SDA)
su(SDA)
SCL
w(SCLL)
h(ST)
w(SCLH)
a. Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both port
12/38 Doc ID 15094 Rev 3
r(SCL)
f(SCL)
h(SDA)
su(SR)
su(SP)
w(SP:SR)
STAR
STOP
LIS331DLHMechanical and electrical specifications
2.4 Absolute maximum ratings
Stresses above those listed as “absolute maximum ratings” may cause permanent damage
to the device. This is a stress rating only and functional operation of the device under these
conditions is not implied. Exposure to maximum rating conditions for extended periods may
affect device reliability.
Table 7.Absolute maximum ratings
SymbolRatingsMaximum valueUnit
VddSupply voltage-0.3 to 6V
Vdd_IOI/O pins Supply voltage-0.3 to 6V
Vin
A
POW
A
UNP
T
T
STG
ESDElectrostatic discharge protection
Input voltage on any control pin
(CS, SCL/SPC, SDA/SDI/SDO, SDO/SA0)
-0.3 to Vdd_IO +0.3V
3000 g for 0.5 ms
Acceleration (any axis, powered, Vdd = 2.5 V)
10000 g for 0.1 ms
3000 g for 0.5 ms
Acceleration (any axis, unpowered)
10000 g for 0.1 ms
Operating temperature range-40 to +85°C
OP
Storage temperature range-40 to +125°C
4 (HBM)kV
1.5 (CDM)kV
200 (MM)V
Note:Supply voltage on any pin should never exceed 6.0 V
This is a mechanical shock sensitive device, improper handling can cause permanent
damages to the part
This is an ESD sensitive device, improper handling can cause permanent damages to
the part
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Mechanical and electrical specificationsLIS331DLH
2.5 Terminology
2.5.1 Sensitivity
Sensitivity describes the gain of the sensor and can be determined e.g. by applying 1 g
acceleration to it. As the sensor can measure DC accelerations this can be done easily by
pointing the axis of interest towards the center of the earth, noting the output value, rotating
the sensor by 180 degrees (pointing to the sky) and noting the output value again. By doing
so, ±1 g acceleration is applied to the sensor. Subtracting the larger output value from the
smaller one, and dividing the result by 2, leads to the actual sensitivity of the sensor. This
value changes very little over temperature and also time. The sensitivity tolerance describes
the range of Sensitivities of a large population of sensors.
2.5.2 Zero-g level
Zero-g level offset (TyOff) describes the deviation of an actual output signal from the ideal
output signal if no acceleration is present. A sensor in a steady state on a horizontal surface
will measure 0 g in X axis and 0 g in Y axis whereas the Z axis will measure 1 g. The output
is ideally in the middle of the dynamic range of the sensor (content of OUT registers 00h,
data expressed as 2’s complement number). A deviation from ideal value in this case is
called Zero-g offset. Offset is to some extent a result of stress to MEMS sensor and
therefore the offset can slightly change after mounting the sensor onto a printed circuit
board or exposing it to extensive mechanical stress. Offset changes little over temperature,
see “Zero-g level change vs. temperature”. The Zero-g level tolerance (TyOff) describes the
standard deviation of the range of Zero-g levels of a population of sensors.
2.5.3 Self-test
Self-test allows to check the sensor functionality without moving it. The self-test function is
off when the self-test bit (ST) of CTRL_REG4 (control register 4) is programmed to ‘0‘.
When the self-test bit of CTRL_REG4 is programmed to ‘1‘ an actuation force is applied to
the sensor, simulating a definite input acceleration. In this case the sensor outputs will
exhibit a change in their DC levels which are related to the selected full scale through the
device sensitivity. When self-test is activated, the device output level is given by the
algebraic sum of the signals produced by the acceleration acting on the sensor and by the
electrostatic test-force. If the output signals change within the amplitude specified inside
Table 3, then the sensor is working properly and the parameters of the interface chip are
within the defined specifications.
2.5.4 Sleep to wake-up
The “sleep to wake-up” function, in conjunction with low-power mode, allows to further
reduce the system power consumption and develop new smart applications.
LIS331DLH may be set in a low-power operating mode, characterized by lower date rates
refreshments. In this way the device, even if sleeping, keep on sensing acceleration and
generating interrupt requests.
When the “sleep to wake-up” function is activated, LIS331DLH is able to automatically
wake-up as soon as the interrupt event has been detected, increasing the output data rate
and bandwidth.
With this feature the system may be efficiently switched from low-power mode to fullperformance depending on user-selectable positioning and acceleration events, thus
ensuring power saving and flexibility.
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LIS331DLHFunctionality
3 Functionality
The LIS331DLH is a “nano”, low-power, digital output 3-axis linear accelerometer packaged
in a LGA package. The complete device includes a sensing element and an IC interface
able to take the information from the sensing element and to provide a signal to the external
world through an I
3.1 Sensing element
A proprietary process is used to create a surface micro-machined accelerometer. The
technology allows to carry out suspended silicon structures which are attached to the
substrate in a few points called anchors and are free to move in the direction of the sensed
acceleration. To be compatible with the traditional packaging techniques a cap is placed on
top of the sensing element to avoid blocking the moving parts during the moulding phase of
the plastic encapsulation.
When an acceleration is applied to the sensor the proof mass displaces from its nominal
position, causing an imbalance in the capacitive half-bridge. This imbalance is measured
using charge integration in response to a voltage pulse applied to the capacitor.
At steady state the nominal value of the capacitors are few pF and when an acceleration is
applied the maximum variation of the capacitive load is in the fF range.
2
C/SPI serial interface.
3.2 IC interface
The complete measurement chain is composed by a low-noise capacitive amplifier which
converts the capacitive unbalancing of the MEMS sensor into an analog voltage that is
finally available to the user by an analog-to-digital converter.
The acceleration data may be accessed through an I
device particularly suitable for direct interfacing with a microcontroller.
The LIS331DLH features a Data-Ready signal (RDY) which indicates when a new set of
measured acceleration data is available thus simplifying data synchronization in the digital
system that uses the device.
The LIS331DLH may also be configured to generate an inertial Wake-Up and Free-Fall
interrupt signal accordingly to a programmed acceleration event along the enabled axes.
Both Free-Fall and Wake-Up can be available simultaneously on two different pins.
3.3 Factory calibration
The IC interface is factory calibrated for sensitivity (So) and Zero-g level (TyOff).
The trimming values are stored inside the device in a non volatile memory. Any time the
device is turned on, the trimming parameters are downloaded into the registers to be used
during the active operation. This allows to use the device without further calibration.
2
C/SPI interface thus making the
Doc ID 15094 Rev 315/38
Application hintsLIS331DLH
4 Application hints
Figure 5.LIS331DLH electrical connection
Vdd
TOP VIEW
6
SDA/SDI/SDO
1416
8
SDO/SA0
CS
13
INT 1
9
9
INT 2
10µF
100nF
GND
Vdd_IO
SCL/SPC
1
5
5
Digital signal from/to signal controller.Signal’s levels are defined by proper selection of Vdd_IO
The device core is supplied through Vdd line while the I/O pads are supplied through
Vdd_IO line. Power supply decoupling capacitors (100 nF ceramic, 10 µF Aluminum) should
be placed as near as possible to the pin 14 of the device (common design practice).
All the voltage and ground supplies must be present at the same time to have proper
behavior of the IC (refer to Figure 5). It is possible to remove Vdd maintaining Vdd_IO
without blocking the communication bus, in this condition the measurement chain is
powered off.
The functionality of the device and the measured acceleration data is selectable and
accessible through the I
2
C or SPI interfaces.When using the I2C, CS must be tied high.
The functions, the threshold and the timing of the two interrupt pins (INT 1 and INT 2) can be
completely programmed by the user through the I
4.1 Soldering information
The LGA package is compliant with the ECOPACK®, RoHS and “Green” standard.
It is qualified for soldering heat resistance according to JEDEC J-STD-020C.
Leave “pin 1 indicator” unconnected during soldering.
16/38 Doc ID 15094 Rev 3
Land pattern and soldering recommendations are available at www.st.com
2
C/SPI interface.
.
LIS331DLHDigital interfaces
5 Digital interfaces
The registers embedded inside the LIS331DLH may be accessed through both the I2C and
SPI serial interfaces. The latter may be SW configured to operate either in 3-wire or 4-wire
interface mode.
The serial interfaces are mapped onto the same pads. To select/exploit the I
line must be tied high (i.e. connected to Vdd_IO).
I
SPI serial data input (SDI)
3-wire interface serial data output (SDO)
2
C less significant bit of the device address (SA0)
I
SPI serial data output (SDO)
5.1 I2C serial interface
The LIS331DLH I2C is a bus slave. The I2C is employed to write data into registers whose
content can also be read back.
The relevant I
Table 9.Serial interface pin description
TransmitterThe device which sends data to the bus
ReceiverThe device which receives data from the bus
2
C terminology is given in the table below.
TermDescription
Master
The device which initiates a transfer, generates clock signals and terminates a
transfer
SlaveThe device addressed by the master
There are two signals associated with the I2C bus: the serial clock line (SCL) and the serial
data line (SDA). The latter is a bidirectional line used for sending and receiving the data
to/from the interface. Both the lines are connected to Vdd_IO through a pull-up resistor
embedded inside the LIS331DLH. When the bus is free both the lines are high.
2
The I
C interface is compliant with fast mode (400 kHz) I2C standards as well as with the
normal mode.
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Digital interfacesLIS331DLH
5.1.1 I2C operation
The transaction on the bus is started through a START (ST) signal. A START condition is
defined as a HIGH to LOW transition on the data line while the SCL line is held HIGH. After
this has been transmitted by the Master, the bus is considered busy. The next byte of data
transmitted after the start condition contains the address of the slave in the first 7 bits and
the eighth bit tells whether the Master is receiving data from the slave or transmitting data to
the slave. When an address is sent, each device in the system compares the first seven bits
after a start condition with its address. If they match, the device considers itself addressed
by the Master.
The Slave ADdress (SAD) associated to the LIS331DLH is 001100xb. SDO/SA0 pad can be
used to modify less significant bit of the device address. If SA0 pad is connected to voltage
supply, LSb is ‘1’ (address 0011001b) else if SA0 pad is connected to ground, LSb value is
‘0’ (address 0011000b). This solution permits to connect and address two different
accelerometers to the same I
Data transfer with acknowledge is mandatory. The transmitter must release the SDA line
during the acknowledge pulse. The receiver must then pull the data line LOW so that it
remains stable low during the HIGH period of the acknowledge clock pulse. A receiver which
has been addressed is obliged to generate an acknowledge after each byte of data
received.
2
The I
C embedded inside the LIS331DLH behaves like a slave device and the following
protocol must be adhered to. After the start condition (ST) a slave address is sent, once a
slave acknowledge (SAK) has been returned, a 8-bit sub-address (SUB) is transmitted: the
7 LSb represent the actual register address while the MSB enables address auto increment.
If the MSb of the SUB field is ‘1’, the SUB (register address) is automatically increased to
allow multiple data read/write.
2
C lines.
The slave address is completed with a Read/Write bit. If the bit was ‘1’ (Read), a repeated
START (SR) condition must be issued after the two sub-address bytes; if the bit is ‘0’ (Write)
the Master will transmit to the slave with direction unchanged. Table explains how the
SAD+Read/Write bit pattern is composed, listing all the possible configurations.
Table 10.SAD+Read/Write patterns
CommandSAD[6:1]SAD[0] = SA0R/WSAD+R/W
Read0011000100110001 (31h)
Write0011000000110000 (30h)
Read0011001100110011 (33h)
Write0011001000110010 (32h)
Table 11.Transfer when master is writing one byte to slave
MasterSTSAD + WSUBDATASP
SlaveSAKSAKSAK
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LIS331DLHDigital interfaces
Table 12.Transfer when master is writing multiple bytes to slave:
MasterSTSAD + WSUBDATADATASP
SlaveSAKSAKSAKSAK
Table 13.Transfer when master is receiving (reading) one byte of data from slave:
MasterSTSAD + WSUBSRSAD + RNMAKSP
SlaveSAKSAKSAKDATA
Table 14.Transfer when Master is receiving (reading) multiple bytes of data from slave
Master ST SAD+WSUBSR SAD+RMAKMAKNMAK SP
SlaveSAKSAKSAKDATADATADATA
Data are transmitted in byte format (DATA). Each data transfer contains 8 bits. The number
of bytes transferred per transfer is unlimited. Data is transferred with the Most Significant bit
(MSb) first. If a receiver can’t receive another complete byte of data until it has performed
some other function, it can hold the clock line, SCL LOW to force the transmitter into a wait
state. Data transfer only continues when the receiver is ready for another byte and releases
the data line. If a slave receiver doesn’t acknowledge the slave address (i.e. it is not able to
receive because it is performing some real time function) the data line must be left HIGH by
the slave. The Master can then abort the transfer. A LOW to HIGH transition on the SDA line
while the SCL line is HIGH is defined as a STOP condition. Each data transfer must be
terminated by the generation of a STOP (SP) condition.
In order to read multiple bytes, it is necessary to assert the most significant bit of the subaddress field. In other words, SUB(7) must be equal to 1 while SUB(6-0) represents the
address of first register to be read.
In the presented communication format MAK is Master acknowledge and NMAK is no
master acknowledge.
5.2 SPI bus interface
The LIS331DLH SPI is a bus slave. The SPI allows to write and read the registers of the
device.
The Serial Interface interacts with the outside world with 4 wires: CS, SPC, SDI and SDO.
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Digital interfacesLIS331DLH
Figure 6.Read and write protocol
CS
SPC
SDI
RW
MS
AD5 AD4 AD3 AD2 AD1 AD0
DI7DI6DI5DI4DI3DI2DI1DI0
SDO
DO7DO6DO5DO4DO3DO2DO1DO0
CS is the serial port enable and it is controlled by the SPI master. It goes low at the start of
the transmission and goes back high at the end. SPC is the serial port clock and it is
controlled by the SPI master. It is stopped high when CS is high (no transmission). SDI and SDO are respectively the serial port data input and output. Those lines are driven at the
falling edge of SPC and should be captured at the rising edge of SPC.
Both the read register and write register commands are completed in 16 clock pulses or in
multiple of 8 in case of multiple bytes read/write. Bit duration is the time between two falling
edges of SPC. The first bit (bit 0) starts at the first falling edge of SPC after the falling edge
of CS while the last bit (bit 15, bit 23, ...) starts at the last falling edge of SPC just before the
rising edge of CS.
5.2.1 SPI read
bit 0: RW
bit. When 0, the data DI(7:0) is written into the device. When 1, the data DO(7:0)
from the device is read. In latter case, the chip will drive SDO at the start of bit 8.
bit 1: MS
bit. When 0, the address will remain unchanged in multiple read/write commands.
When 1, the address is auto incremented in multiple read/write commands.
bit 2-7: address AD(5:0). This is the address field of the indexed register.
bit 8-15: data DI(7:0) (write mode). This is the data that is written into the device (MSb first).
bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first).
In multiple read/write commands further blocks of 8 clock periods will be added. When MS
bit is ‘0’ the address used to read/write data remains the same for every block. When MS
bit
is ‘1’ the address used to read/write data is increased at every block.
The function and the behavior of SDI and SDO remain unchanged.
Figure 7.SPI read protocol
CS
SPC
SDI
RW
MS
AD5 AD4 AD3 AD2 AD1 AD0
SDO
DO7 DO6 DO5DO4 DO3 DO2 DO1DO0
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LIS331DLHDigital interfaces
The SPI Read command is performed with 16 clock pulses. Multiple byte read command is
performed adding blocks of 8 clock pulses at the previous one.
bit 0: READ bit. The value is 1.
bit 1: MS
bit. When 0 do not increment address, when 1 increment address in multiple
reading.
bit 2-7: address AD(5:0). This is the address field of the indexed register.
bit 8-15: data DO(7:0) (read mode). This is the data that will be read from the device (MSb
first).
bit 16-... : data DO(...-8). Further data in multiple byte reading.
3-wires mode is entered by setting to ‘1’ bit SIM (SPI serial interface mode selection) in
CTRL_REG4.
Figure 11. SPI read protocol in 3-wires mode
CS
SPC
SDI/O
RW
MS
AD5 AD4 AD3 AD2 AD1 AD0
DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
The SPI read command is performed with 16 clock pulses:
bit 0: READ bit. The value is 1.
bit 1: MS
bit. When 0 do not increment address, when 1 increment address in multiple
reading.
bit 2-7: address AD(5:0). This is the address field of the indexed register.
bit 8-15: data DO(7:0) (read mode). This is the data that is read from the device (MSb first).
Multiple read command is also available in 3-wires mode.
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LIS331DLHRegister mapping
6 Register mapping
The table given below provides a listing of the 8 bit registers embedded in the device and
the related addresses:
Table 15.Register address map
Register address
NameType
HexBinary
Reserved (do not modify)00 - 0EReserved
WHO_AM_Ir0F000 1111 00110010 Dummy register
Reserved (do not modify)10 - 1FReserved
CTRL_REG1rw20010 0000 00000111
CTRL_REG2rw21010 0001 00000000
CTRL_REG3rw22010 0010 00000000
CTRL_REG4rw23010 0011 00000000
CTRL_REG5rw24010 0100 00000000
HP_FILTER_RESETr25010 0101Dummy register
REFERENCErw26010 0110 00000000
DefaultComment
STATUS_REGr27010 0111 00000000
OUT_X_Lr28010 1000output
OUT_X_Hr29010 1001output
OUT_Y_Lr2A010 1010output
OUT_Y_Hr2B010 1011output
OUT_Z_Lr2C010 1100output
OUT_Z_Hr2D010 1101output
Reserved (do not modify)2E - 2FReserved
INT1_CFGrw30011 0000 00000000
INT1_SOURCEr31011 0001 00000000
INT1_THSrw32011 0010 00000000
INT1_DURATIONrw33011 0011 00000000
INT2_CFGrw34011 0100 00000000
INT2_SOURCEr35011 0101 00000000
INT2_THSrw36011 0110 00000000
INT2_DURATIONrw37011 0111 00000000
Reserved (do not modify)38 - 3FReserved
Registers marked as Reserved must not be changed. The writing to those registers may
cause permanent damages to the device.
Doc ID 15094 Rev 323/38
Register mappingLIS331DLH
The content of the registers that are loaded at boot should not be changed. They contain the
factory calibration values. Their content is automatically restored when the device is
powered-up.
24/38 Doc ID 15094 Rev 3
LIS331DLHRegister description
7 Register description
The device contains a set of registers which are used to control its behavior and to retrieve
acceleration data. The registers address, made of 7 bits, is used to identify them and to
write the data through serial interface.
7.1 WHO_AM_I (0Fh)
Table 16.WHO_AM_I register
00110010
Device identification register.
This register contains the device identifier that for LIS331DLH is set to 32h.
7.2 CTRL_REG1 (20h)
Table 17.CTRL_REG1 register
PM2PM1PM0DR1DR0ZenYenXen
Table 18.CTRL_REG1 description
PM2 - PM0
DR1, DR0
Zen
Ye n
Xen
Power mode selection. Default value: 000
(000: Power-down; Others: refer to Table 19)
Data rate selection. Default value: 00
(00:50 Hz; Others: refer to Table 20)
Z axis enable. Default value: 1
(0: Z axis disabled; 1: Z axis enabled)
Y axis enable. Default value: 1
(0: Y axis disabled; 1: Y axis enabled)
X axis enable. Default value: 1
(0: X axis disabled; 1: X axis enabled)
PM bits allow to select between power-down and two operating active modes. The device is
in power-down mode when PD bits are set to “000” (default value after boot). Table 19
shows all the possible power mode configurations and respective output data rates. Output
data in the low-power modes are computed with low-pass filter cut-off frequency defined by
DR1, DR0 bits.
DR bits, in the normal-mode operation, select the data rate at which acceleration samples
are produced. In low-power mode they define the output data resolution. Table 20 shows all
the possible configuration for DR1 and DR0 bits.
Doc ID 15094 Rev 325/38
Register descriptionLIS331DLH
Table 19.Power mode and low-power output data rate configurations
PM2PM1PM0Power mode selection
Output data rate [Hz]
ODR
LP
000Power-down--
001Normal modeODR
010Low-power0.5
011Low-power1
100Low-power2
101Low-power5
110Low-power10
Table 20.Normal-mode output data rate configurations and low-pass cut-off
High pass filter mode selection. Default value: 00
(00: normal mode; Others: refer to Table 23)
Filtered data selection. Default value: 0
(0: internal filter bypassed; 1: data from internal filter sent to output register)
High pass filter enabled for interrupt 2 source. Default value: 0
(0: filter bypassed; 1: filter enabled)
26/38 Doc ID 15094 Rev 3
LIS331DLHRegister description
Table 22.CTRL_REG2 description (continued)
HPen1
HPCF1,
HPCF0
High pass filter enabled for interrupt 1 source. Default value: 0
(0: filter bypassed; 1: filter enabled)
High pass filter cut-off frequency configuration. Default value: 00
(00: HPc=8; 01: HPc=16; 10: HPc=32; 11: HPc=64)
BOOT bit is used to refresh the content of internal registers stored in the flash memory
block. At the device power up the content of the flash memory block is transferred to the
internal registers related to trimming functions to permit a good behavior of the device itself.
If for any reason the content of trimming registers was changed it is sufficient to use this bit
to restore correct values. When BOOT bit is set to ‘1’ the content of internal flash is copied
inside corresponding internal registers and it is used to calibrate the device. These values
are factory trimmed and they are different for every accelerometer. They permit a good
behavior of the device and normally they have not to be changed. At the end of the boot
process the BOOT bit is set again to ‘0’.
Table 23.High-pass filter mode configuration
HPM1HPM0High-pass filter mode
00Normal mode (reset reading HP_RESET_FILTER)
01Reference signal for filtering
10Normal mode (reset reading HP_RESET_FILTER)
HPCF[1:0]. These bits are used to configure high-pass filter cut-off frequency f
which is
t
given by:
f
⎛⎞
f
1
t
⎝⎠
1
----------- -–
HPc
s
------
⋅ln=
2π
The equation can be simplified to the following approximated equation:
f
----------------------=
6HPc⋅
s
Data rate = 400 Hz
ft [Hz]
ft [Hz]
Data rate = 1000 Hz
f
t
Table 24.High-pass filter cut-off frequency configuration
HPcoeff2,1
[Hz]
f
t
Data rate = 50 Hz
ft [Hz]
Data rate = 100 Hz
0012820
010.51410
100.250.525
110.1250.2512.5
Doc ID 15094 Rev 327/38
Register descriptionLIS331DLH
7.4 CTRL_REG3 [Interrupt CTRL register] (22h)
Table 25.CTRL_REG3 register
IHLPP_ODLIR2I2_CFG1I2_CFG0LIR1I1_CFG1I1_CFG0
Table 26.CTRL_REG3 description
IHL
PP_OD
LIR2
Interrupt active high, low. Default value: 0
(0: active high; 1:active low)
Push-pull/Open drain selection on interrupt pad. Default value 0.
(0: push-pull; 1: open drain)
Latch interrupt request on INT2_SRC register, with INT2_SRC register cleared by
reading INT2_SRC itself. Default value: 0.
(0: interrupt request not latched; 1: interrupt request latched)
I2_CFG1,
I2_CFG0
Data signal on INT 2 pad control bits. Default value: 00.
(see table below)
Latch interrupt request on INT1_SRC register, with INT1_SRC register cleared by
BDU bit is used to inhibit output registers update between the reading of upper and lower
register parts. In default mode (BDU = ‘0’) the lower and upper register parts are updated
continuously. If it is not sure to read faster than output data rate, it is recommended to set
BDU bit to ‘1’. In this way, after the reading of the lower (upper) register part, the content of
that output registers is not updated until the upper (lower) part is read too.
This feature avoids reading LSB and MSB related to different samples.
7.6 CTRL_REG5 (24h)
Table 30.CTRL_REG5 register
000000TurnOn1TurnOn0
Table 31.CTRL_REG5 description
Tu r n On 1 ,
Tu r n On 0
Turn-on mode selection for sleep to wake function. Default value: 00.
Turn On bits are used for turning on the sleep to wake function.
Table 32.Sleep to wake configuration
TurnOn1TurnOn0Sleep to wake status
00Sleep to wake function is disabled
11
Turned on: The device is in low power mode (ODR is defined in
CTRL_REG1)
Setting TurnOn[1:0] bits to 11 the “sleep to wake” function is enabled. When an interrupt
event occurs the device is turned to normal mode increasing the ODR to the value defined in
CTRL_REG1. Although the device is in normal mode, CTRL_REG1 content is not
automatically changed to “normal mode” configuration.
Doc ID 15094 Rev 329/38
Register descriptionLIS331DLH
7.7 HP_FILTER_RESET (25h)
Dummy register. Reading at this address zeroes instantaneously the content of the internal
high pass-filter. If the high pass filter is enabled all three axes are instantaneously set to 0g.
This allows to overcome the settling time of the high pass filter.
7.8 REFERENCE (26h)
Table 33.REFERENCE register
Ref7Ref6Ref5Ref4Ref3Ref2Ref1Ref0
Table 34.REFERENCE description
Ref7 - Ref0Reference value for high-pass filter. Default value: 00h.
This register sets the acceleration value taken as a reference for the high-pass filter output.
When filter is turned on (at least one of FDS, HPen2, or HPen1 bit is equal to ‘1’) and HPM
bits are set to “01”, filter out is generated taking this value as a reference.
7.9 STATUS_REG (27h)
Table 35.STATUS_REG register
ZYXORZORYORXORZYXDAZDAYDAXDA
Table 36.STATUS_REG description
X, Y and Z axis data overrun. Default value: 0
ZYXOR
ZOR
YOR
XOR
ZYXDAX, Y and Z axis new data available. Default value: 0
(0: no overrun has occurred;
1: new data has overwritten the previous one before it was read)
Z axis data overrun. Default value: 0
(0: no overrun has occurred;
1: a new data for the Z-axis has overwritten the previous one)
Y axis data overrun. Default value: 0
(0: no overrun has occurred;
1: a new data for the Y-axis has overwritten the previous one)
X axis data overrun. Default value: 0
(0: no overrun has occurred;
1: a new data for the X-axis has overwritten the previous one)
(0: a new set of data is not yet available; 1: a new set of data is available)
30/38 Doc ID 15094 Rev 3
LIS331DLHRegister description
Table 36.STATUS_REG description (continued)
ZDAZ axis new data available. Default value: 0
(0: a new data for the Z-axis is not yet available;
1: a new data for the Z-axis is available)
YDAY axis new data available. Default value: 0
(0: a new data for the Y-axis is not yet available;
1: a new data for the Y-axis is available)
XDAX axis new data available. Default value: 0
(0: a new data for the X-axis is not yet available;
1: a new data for the X-axis is available)
7.10 OUT_X_L (28h), OUT_X_H (29)
X-axis acceleration data. The value is expressed as two’s complement.
7.11 OUT_Y_L (2Ah), OUT_Y_H (2Bh)
Y-axis acceleration data. The value is expressed as two’s complement.
7.12 OUT_Z_L (2Ch), OUT_Z_H (2Dh)
Z-axis acceleration data. The value is expressed as two’s complement.
7.13 INT1_CFG (30h)
Table 37.INT1_CFG register
AOI6DZHIEZLIEYHIEYLIEXHIEXLIE
Table 38.INT1_CFG description
AOI
6D
ZHIE
ZLIE
YHIE
AND/OR combination of Interrupt events. Default value: 0.
(See Table 39)
6 direction detection function enable. Default value: 0.
(See Table 39)
Enable interrupt generation on Z high event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
Enable interrupt generation on Z low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Enable interrupt generation on Y high event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
Doc ID 15094 Rev 331/38
Register descriptionLIS331DLH
Table 38.INT1_CFG description
Enable interrupt generation on Y low event. Default value: 0
YLIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Enable interrupt generation on X high event. Default value: 0
XHIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
Enable interrupt generation on X low event. Default value: 0
XLIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Configuration register for Interrupt 1 source.
Table 39.Interrupt 1 source configurations
AOI6DInterrupt mode
00OR combination of interrupt events
016 direction movement recognition
10AND combination of interrupt events
116 direction position recognition
7.14 INT1_SRC (31h)
Table 40.INT1_SRC register
0 IA ZHZLYHYLXHXL
Table 41.INT1_SRC description
IA
ZH
ZL
YH
YL
XH
XL
Interrupt active. Default value: 0
(0: no interrupt has been generated; 1: one or more interrupts have been generated)
Z high. Default value: 0
(0: no interrupt, 1: Z High event has occurred)
Z low. Default value: 0
(0: no interrupt; 1: Z Low event has occurred)
Y high. Default value: 0
(0: no interrupt, 1: Y High event has occurred)
Y low. Default value: 0
(0: no interrupt, 1: Y Low event has occurred)
X high. Default value: 0
(0: no interrupt, 1: X High event has occurred)
X low. Default value: 0
(0: no interrupt, 1: X Low event has occurred)
32/38 Doc ID 15094 Rev 3
LIS331DLHRegister description
Interrupt 1 source register. Read only register.
Reading at this address clears INT1_SRC IA bit (and the interrupt signal on INT 1 pin) and
allows the refreshment of data in the INT1_SRC register if the latched option was chosen.
D6 - D0 bits set the minimum duration of the Interrupt 2 event to be recognized. Duration
steps and maximum values depend on the ODR chosen.
7.17 INT2_CFG (34h)
Table 46.INT2_CFG register
AOI6DZHIEZLIEYHIEYLIEXHIEXLIE
Table 47.INT2_CFG description
AOI
6D
ZHIE
AND/OR combination of interrupt events. Default value: 0.
(See table below)
6 direction detection function enable. Default value: 0.
(See table below)
Enable interrupt generation on Z high event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
ZLIE
Enable interrupt generation on Z low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Doc ID 15094 Rev 333/38
Register descriptionLIS331DLH
Table 47.INT2_CFG description (continued)
Enable interrupt generation on Y high event. Default value: 0
YHIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
Enable interrupt generation on Y low event. Default value: 0
YLIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Enable interrupt generation on X high event. Default value: 0
XHIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
Enable interrupt generation on X low event. Default value: 0
XLIE
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Configuration register for Interrupt 2 source.
Table 48.Interrupt mode configuration
AOI6DInterrupt mode
00OR combination of interrupt events
016 direction movement recognition
10AND combination of interrupt events
116 direction position recognition
7.18 INT2_SRC (35h)
Table 49.INT2_SRC register
0 IA ZHZLYHYLXHXL
Table 50.INT2_SRC description
IA
ZH
ZL
YH
YL
Interrupt active. Default value: 0
(0: no interrupt has been generated; 1: one or more interrupts have been generated)
Z high. Default value: 0
(0: no interrupt, 1: Z high event has occurred)
Z low. Default value: 0
(0: no interrupt; 1: Z low event has occurred)
Y high. Default value: 0
(0: no interrupt, 1: Y high event has occurred)
Y low. Default value: 0
(0: no interrupt, 1: Y low event has occurred)
34/38 Doc ID 15094 Rev 3
LIS331DLHRegister description
Table 50.INT2_SRC description
XH
XL
X high. Default value: 0
(0: no interrupt, 1: X high event has occurred)
X Low. Default value: 0
(0: no interrupt, 1: X low event has occurred)
Interrupt 2 source register. Read only register.
Reading at this address clears INT2_SRC IA bit (and the interrupt signal on INT 2 pin) and
allows the refreshment of data in the INT2_SRC register if the latched option was chosen.
D6 - D0 bits set the minimum duration of the Interrupt 2 event to be recognized. Duration
time steps and maximum values depend on the ODR chosen.
Doc ID 15094 Rev 335/38
Package informationLIS331DLH
8 Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
®
packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK is an ST trademark.
Figure 12. LGA16: mechanical data and package dimensions
Dimensions
Ref.
A11.0000.0394
A20.7850.0309
A30.2000.0079
D12.850 3.000 3.150 0.1122 0.11
E12.850 3.000 3.150 0.1122 0.11
L11.000 1.0600.0
L22.000 2.0600.07
N10.5000.0197
N21.0000.0394
M0.040 0.100 0.160 0.0016 0.00
P10.8750.0344
P21.2750.0502
T10.2900.350 0.410 0.0114 0.01
T20.190 0.250 0.310 0.0075 0.0098 0.0122
d0.1500.0059
k0.0500.0020
mminch
Min. Typ. Max. Min. Typ. Max.
81 0.1240
81 0.1240
394 0.0417
870.0811
39 0.0063
38 0.0161
Land Grid Array Package
Outline and
mechanical data
LGA16 (3x3x1.0mm)
36/38 Doc ID 15094 Rev 3
7983231
LIS331DLHRevision history
9 Revision history
Table 55.Document revision history
DateRevisionChanges
16-Oct-20081Initial release
21-Nov-20082Updated Table 3 on page 9 and Table 4 on page 10
10-Jul-20093
Updated: Table 4 on page 10 and Table 6 on page 12
Minor text changes to improve readability
Doc ID 15094 Rev 337/38
LIS331DLH
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