July 2009 Doc ID 15102 Rev 4 1/38
38
LIS331DLM
MEMS digital output motion sensor
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
■I2C/SPI digital output interface
■8 bit resolution
■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
Description
The LIS331DLM is an ultra low-power high
performance three axes linear accelerometer
belonging to the “nano” family, with digital I2C/SPI
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 LIS331DLM 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 400 Hz.
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 LIS331DLM 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.
.
LGA 16
(3x3x1 mm)
Table 1. Device summary
Order code Temperature range [°C] Package Packaging
LIS331DLM -40 to +85 LGA 16 Tray
LIS331DLMTR -40 to +85 LGA 16 Tape and reel
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Contents LIS331DLM
2/38 Doc ID 15102 Rev 4
Contents
1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Mechanical and electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 Communication interface characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.1 SPI - serial peripheral interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.2 I2C - Inter IC control interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.2 Zero-g level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.3 Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.4 Sleep to wake-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1 Sensing element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2 IC interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.3 Factory calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.1 Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5 Digital interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1 I2C serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1.1 I2C operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2 SPI bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.2.1 SPI read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.2.2 SPI write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2.3 SPI read in 3-wires mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
LIS331DLM Contents
Doc ID 15102 Rev 4 3/38
6 Register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
7 Register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.1 WHO_AM_I (0Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.2 CTRL_REG1 (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.3 CTRL_REG2 (21h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4 CTRL_REG3 [Interrupt CTRL register] (22h) . . . . . . . . . . . . . . . . . . . . . . 27
7.5 CTRL_REG4 (23h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.6 CTRL_REG5 (24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . h) 28
7.7 HP_FILTER_RESET (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7.8 REFERENCE (26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . h) 28
7.9 STATUS_REG (27h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.10 OUT_X (29) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.11 OUT_Y (2Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
7.12 OUT_Z (2Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.13 INT1_CFG (30h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7.14 INT1_SRC (31h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.15 INT1_THS (32h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.16 INT1_DURATION (33h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.17 INT2_CFG (34h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7.18 INT2_SRC (35h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.19 INT2_THS (36h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.20 INT2_DURATION (37h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
List of tables LIS331DLM
4/38 Doc ID 15102 Rev 4
List of tables
Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Table 2. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Table 3. Mechanical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted . . . . . . . . . . 7
Table 4. Electrical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted . . . . . . . . . . . . 8
Table 5. SPI slave timing values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Table 6. I2C slave timing values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Table 7. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Table 8. Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 9. Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 10. SAD+Read/Write patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 11. Transfer when master is writing one byte to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 12. Transfer when master is writing multiple bytes to slave:. . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 13. Transfer when master is receiving (reading) one byte of data from slave: . . . . . . . . . . . . . 17
Table 14. Transfer when Master is receiving (reading) multiple bytes of data from slave . . . . . . . . . 17
Table 15. Register address map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 16. WHO_AM_I register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 17. CTRL_REG1 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 18. CTRL_REG1 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 19. Power mode and low-power output data rate configurations . . . . . . . . . . . . . . . . . . . . . . . 24
Table 20. Normal-mode output data rate configurations and low-pass cut-off frequencies . . . . . . . . 24
Table 21. CTRL_REG2 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 22. CTRL_REG2 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 23. High-pass filter mode configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 24. High-pass filter cut-off frequency configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 25. CTRL_REG3 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 26. CTRL_REG3 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 27. Data signal on INT 1 and INT 2 pad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 28. CTRL_REG4 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 29. CTRL_REG4 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 30. CTRL_REG5 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 31. CTRL_REG5 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 32. REFERENCE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 33. REFERENCE description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 34. STATUS_REG register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 35. STATUS_REG description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 36. INT1_CFG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 37. INT1_CFG description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 38. Interrupt 1 source configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 39. INT1_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 40. INT1_SRC description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 41. INT1_THS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 42. INT1_THS description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 43. INT1_DURATION register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 44. INT2_DURATION description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 45. INT2_CFG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 46. INT2_CFG description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 47. Interrupt mode configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 48. INT2_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
LIS331DLM List of tables
Doc ID 15102 Rev 4 5/38
Table 49. INT2_SRC description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 50. INT2_THS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 51. INT2_THS description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 52. INT2_DURATION register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 53. INT2_DURATION description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Table 54. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
List of figures LIS331DLM
6/38 Doc ID 15102 Rev 4
List of figures
Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 3. SPI slave timing diagram (2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 4. I2C Slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 5. LIS331DLM electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 6. Read and write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 7. SPI read protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Figure 8. Multiple bytes SPI read protocol (2 bytes example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 9. SPI write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 10. Multiple bytes SPI write protocol (2 bytes example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 11. SPI read protocol in 3-wires mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 12. LGA16: mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
LIS331DLM Block diagram and pin description
Doc ID 15102 Rev 4 7/38
1 Block diagram and pin description
1.1 Block diagram
Figure 1. Block diagram
1.2 Pin description
Figure 2. Pin connection
CHARGE
AMPLIFIER
Y+
Z+
Y-
Z-
a
X+
X-
I
2
C
SPI
CS
SCL/SPC
SDA/SDO/SDI
SDO/SA0
CONTROL LOGIC
&
INTERRUPT GEN.
INT 1
CLOCK
TRIMMING
CIRCUITS
REFERENCESELF TEST
CONTROL LOGIC
A/D
CONVERTER
INT 2
MUX
(TOP VIEW)
DIRECTION OF THE
DETECTABLE
ACCELERATIONS
1
5
9
13
(BOTTOM VIEW)
Y
1
X
Z
Pin 1 indicator
Block diagram and pin description LIS331DLM
8/38 Doc ID 15102 Rev 4
Table 2. Pin description
Pin# Name Function
1 Vdd_IO Power supply for I/O pins
2 NC Not connected
3 NC Not connected
4SCL
SPC
I2C serial clock (SCL)
SPI serial port clock (SPC)
5 GND 0 V supply
6
SDA
SDI
SDO
I2C serial data (SDA)
SPI serial data input (SDI)
3-wire interface serial data output (SDO)
7SDO
SA0
SPI serial data output (SDO)
I2C less significant bit of the device address (SA0)
8CS
SPI enable
I2C/SPI mode selection (1: I2C mode; 0: SPI enabled)
9 INT 2 Inertial interrupt 2
10 Reserved Connect to GND
11 INT 1 Inertial interrupt 1
12 GND 0 V supply
13 GND 0 V supply
14 Vdd Power supply
15 Reserved Connect to Vdd
16 GND 0 V supply
LIS331DLM Mechanical and electrical specifications
Doc ID 15102 Rev 4 9/38
2 Mechanical and electrical specifications
2.1 Mechanical characteristics
Table 3. Mechanical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted (1)
Symbol Parameter Test conditions Min. Typ.(2) Max. Unit
FS Measurement range(3)
FS bit set to 00 ±2.0
gFS bit set to 01 ±4.0
FS bit set to 11 ±8.0
So Sensitivity
FS bit set to 00
8 bit representation 64
LSB/g
FS bit set to 01
8 bit representation 32
FS bit set to 11
8 bit representation 16
Dres Device resolution FS bit set to 00
ODR = 50 Hz 16 mg
TCSo Sensitivity change vs
temperature FS bit set to 00 ±0.01 %/°C
Ty O f f Typical zero-g level offset
accuracy(4),(5) FS bit set to 00 ±40 mg
TCOff Zero-g level change vs
temperature Max delta from 25 °C ±0.5 mg/°C
Vst Self-test
output change(6),(7),(8)
FS bit set to 00
X axis 31732LSb
FS bit set to 00
Y axis -3 -17 -32 LSb
FS bit set to 00
Z axis 31732LSb
Top Operating temperature range -40 +85 °C
Wh Product weight 20 mgram
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.
7.
Self-test output changes with the power supply. “Self-test output change” is defined as
OUTPUT[LSb]
(CTRL_REG4 ST bit=1)
- OUTPUT[LSb](CTRL_REG4 ST bit=0). 1LSb=4g/256 at 8 bit representation, ±2 g full-scale
8. Output data reach 99% of final value after 1/ODR+1 ms when enabling self-test mode, due to device filtering
Mechanical and electrical specifications LIS331DLM
10/38 Doc ID 15102 Rev 4
2.2 Electrical characteristics
Table 4. Electrical characteristics @ Vdd = 2.5 V, T = 25 °C unless otherwise noted (1)
Symbol Parameter Test conditions Min. Typ.(2) Max. Unit
Vdd Supply voltage 2.16 2.5 3.6 V
Vdd_IO I/O pins supply voltage(3) 1.71 Vdd+0.1 V
Idd Current consumption
in normal mode 250 µA
IddLP Current consumption
in low-power mode 10 µA
IddPdn Current consumption in
power-down mode 1µA
VIH Digital high level input
voltage 0.8*Vdd_IO V
VIL Digital low level input voltage 0.2*Vdd_IO V
VOH High level output voltage 0.9*Vdd_IO V
VOL Low level output voltage 0.1*Vdd_IO V
ODR Output data rate
in normal mode
DR bit set to 00 50
HzDR bit set to 01 100
DR bit set to 10 400
ODRLP
Output data rate
in low-power mode
PM bit set to 010 0.5
Hz
PM bit set to 011 1
PM bit set to 100 2
PM bit set to 101 5
PM bit set to 110 10
BW System bandwidth(4) ODR/2 Hz
Ton Turn-on time(5) ODR = 100 Hz 1/ODR+1ms s
Top Operating temperature range -40 +85 °C
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
LIS331DLM Mechanical and electrical specifications
Doc ID 15102 Rev 4 11/38
2.3 Communication interface characteristics
2.3.1 SPI - serial peripheral interface
Subject to general operating conditions for Vdd and Top.
Figure 3. SPI slave timing diagram (2)
1. Values are guaranteed at 10MHz clock frequency for SPI with both 4 and 3 wires, based on characterization results, not
tested in production
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
Table 5. SPI slave timing values
Symbol Parameter
Value (1)
Unit
Min. Max.
tc(SPC) SPI clock cycle 100 ns
fc(SPC) SPI clock frequency 10 MHz
tsu(CS) CS setup time 6
ns
th(CS) CS hold time 8
tsu(SI) SDI input setup time 5
th(SI) SDI input hold time 15
tv(SO) SDO valid output time 50
th(SO) SDO output hold time 9
tdis(SO) SDO output disable time 50
SPC
CS
SDI
SDO
t
su(CS)
t
v(SO)
t
h(SO)
t
h(SI)
t
su(SI)
t
h(CS)
t
dis(SO)
t
c(SPC)
MSB IN
MSB OUT LSB OUT
LSB IN
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
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12/38 Doc ID 15102 Rev 4
2.3.2 I2C - Inter IC control interface
Subject to general operating conditions for Vdd and top.
Figure 4. I2C Slave timing diagram (a)
Table 6. I2C slave timing values
Symbol Parameter
I2C standard mode (1) I2C fast mode (1)
Unit
Min Max Min Max
f(SCL) SCL clock frequency 0 100 0 400 KHz
tw(SCLL) SCL clock low time 4.7 1.3
µs
tw(SCLH) SCL clock high time 4.0 0.6
tsu(SDA) SDA setup time 250 100 ns
th(SDA) SDA data hold time 0.01 3.45 0.01 0.9 µs
tr(SDA) tr(SCL) SDA and SCL rise time 1000 20 + 0.1Cb (2) 300
ns
tf(SDA) tf(SCL) SDA and SCL fall time 300 20 + 0.1Cb (2) 300
th(ST) START condition hold time 4 0.6
µs
tsu(SR) Repeated START condition
setup time 4.7 0.6
tsu(SP) STOP condition setup time 4 0.6
tw(SP:SR) Bus free time between STOP
and START condition 4.7 1.3
1. Data based on standard I2C protocol requirement, not tested in production
2. Cb = total capacitance of one bus line, in pF
a. Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both port
SDA
SCL
t
f(SDA)
t
su(SP)
t
w(SCLL)
t
su(SDA)
t
r(SDA)
t
su(SR)
t
h(ST)
t
w(SCLH)
t
h(SDA)
t
r(SCL)
t
f(SCL)
t
w(SP:SR)
START
REPEATED
START
STOP
STAR
T
LIS331DLM Mechanical and electrical specifications
Doc ID 15102 Rev 4 13/38
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.
Note: Supply voltage on any pin should never exceed 6.0 V
Table 7. Absolute maximum ratings
Symbol Ratings Maximum value Unit
Vdd Supply voltage -0.3 to 6 V
Vdd_IO I/O pins supply voltage -0.3 to 6 V
Vin Input voltage on any control pin
(CS, SCL/SPC, SDA/SDI/SDO, SDO/SA0) -0.3 to Vdd_IO +0.3 V
APOW Acceleration (any axis, powered, Vdd = 2.5 V) 3000 g for 0.5 ms
10000 g for 0.1 ms
AUNP Acceleration (any axis, unpowered) 3000 g for 0.5 ms
10000 g for 0.1 ms
TOP Operating temperature range -40 to +85 °C
TSTG Storage temperature range -40 to +125 °C
ESD Electrostatic discharge protection
4 (HBM) kV
1.5 (CDM) kV
200 (MM) 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
Mechanical and electrical specifications LIS331DLM
14/38 Doc ID 15102 Rev 4
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 algebric
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.
LIS331DLM 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, LIS331DLM 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 full-
performance depending on user-selectable positioning and acceleration events, thus
ensuring power saving and flexibility.
LIS331DLM Functionality
Doc ID 15102 Rev 4 15/38
3 Functionality
The LIS331DLM 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 I2C/SPI serial interface.
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.
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 I2C/SPI interface thus making the
device particularly suitable for direct interfacing with a microcontroller.
The LIS331DLM 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 LIS331DLM 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.
Application hints LIS331DLM
16/38 Doc ID 15102 Rev 4
4 Application hints
Figure 5. LIS331DLM electrical connection
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 I2C 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 I2C/SPI interface.
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.
Land pattern and soldering recommendations are available at www.st.com.
CS
10µF
Vdd
100nF
GND
Vdd_IO
SDO/SA0
SDA/SDI/SDO
INT 1
SCL/SPC
Digital signal from/to signal controller.Signal’s levels are defined by proper selection of Vdd_IO
1
5
8
13
TOP VIEW
6
9
1416
9
5
INT 2
LIS331DLM Digital interfaces
Doc ID 15102 Rev 4 17/38
5 Digital interfaces
The registers embedded inside the LIS331DLM 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 I2C interface, CS
line must be tied high (i.e. connected to Vdd_IO).
5.1 I2C serial interface
The LIS331DLM I2C is a bus slave. The I2C is employed to write data into registers whose
content can also be read back.
The relevant I2C terminology is given in the table below.
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 LIS331DLM. When the bus is free both the lines are high.
The I2C interface is compliant with fast mode (400 kHz) I2C standards as well as with the
normal mode.
Table 8. Serial interface pin description
Pin name Pin description
CS SPI enable
I2C/SPI mode selection (1: I2C mode; 0: SPI enabled)
SCL
SPC
I2C serial clock (SCL)
SPI serial port clock (SPC)
SDA
SDI
SDO
I2C serial data (SDA)
SPI serial data input (SDI)
3-wire interface serial data output (SDO)
SA0
SDO
I2C less significant bit of the device address (SA0)
SPI serial data output (SDO)
Table 9. Serial interface pin description
Term Description
Transmitter The device which sends data to the bus
Receiver The device which receives data from the bus
Master The device which initiates a transfer, generates clock signals and terminates a
transfer
Slave The device addressed by the master
Digital interfaces LIS331DLM
18/38 Doc ID 15102 Rev 4
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 LIS331DLM is 000100xb. 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 0001001b) else if SA0 pad is connected to ground, LSb value is
‘0’ (address 0001000b). This solution permits to connect and address two different
accelerometers to the same I2C lines.
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.
The I2C embedded inside the LIS331DLM 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 incremented to
allow multiple data read/write.
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
Command SAD[6:1] SAD[0] = SA0 R/W SAD+R/W
Read 000100 0 1 00010001 (11h)
Write 000100 0 0 00010000 (10h)
Read 000100 1 1 00010011 (13h)
Write 000100 1 0 00010010 (12h)
Table 11. Transfer when master is writing one byte to slave
Master ST SAD + W SUB DATA SP
Slave SAK SAK SAK
LIS331DLM Digital interfaces
Doc ID 15102 Rev 4 19/38
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 sub-
address 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 LIS331DLM 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.
Table 12. Transfer when master is writing multiple bytes to slave:
Master ST SAD + W SUB DATA DATA SP
Slave SAK SAK SAK SAK
Table 13. Transfer when master is receiving (reading) one byte of data from slave:
Master ST SAD + W SUB SR SAD + R NMAK SP
Slave SAK SAK SAK DATA
Table 14. Transfer when Master is receiving (reading) multiple bytes of data from slave
Master ST SAD+W SUB SR SAD+R MAK MAK NMAK SP
Slave SAK SAK SAK DATA DATA DATA
Digital interfaces LIS331DLM
20/38 Doc ID 15102 Rev 4
Figure 6. Read and write protocol
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.
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 incremented at every block.
The function and the behavior of SDI and SDO remain unchanged.
5.2.1 SPI read
Figure 7. SPI read protocol
CS
SPC
SDI
SDO
RW
AD5 AD4 AD3 AD2 AD1 AD0
DI7DI6DI5DI4DI3DI2DI1DI0
DO7DO6DO5DO4DO3DO2DO1DO0
MS
CS
SPC
SDI
SDO
RW
DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
AD5 AD4 AD3 AD2 AD1 AD0
MS
LIS331DLM Digital interfaces
Doc ID 15102 Rev 4 21/38
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.
Figure 8. Multiple bytes SPI read protocol (2 bytes example)
5.2.2 SPI write
Figure 9. SPI write protocol
The SPI Write command is performed with 16 clock pulses. Multiple byte write command is
performed adding blocks of 8 clock pulses at the previous one.
bit 0: WRITE bit. The value is 0.
bit 1: MS bit. When 0 do not increment address, when 1 increment address in multiple
writing.
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 inside the device (MSb
first).
bit 16-... : data DI(...-8). Further data in multiple byte writing.
CS
SPC
SDI
SDO
RW
DO7DO6DO5DO4DO3DO2DO1DO0
AD5 AD4 AD3 AD2 AD1 AD0
DO15 DO14 DO13 DO12 DO11 DO10 DO9 DO8
MS
CS
SPC
SDI
RW DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0
AD5 AD4 AD3 AD2 AD1 AD0MS
Digital interfaces LIS331DLM
22/38 Doc ID 15102 Rev 4
Figure 10. Multiple bytes SPI write protocol (2 bytes example)
5.2.3 SPI read in 3-wires mode
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
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.
CS
SPC
SDI
RW
AD5 AD4 AD3 AD2 AD1 AD0
DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 DI15 DI14 DI13 DI12 DI11 DI10 DI9 DI8
MS
CS
SPC
SDI/O
RW DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
AD5 AD4 AD3 AD2 AD1 AD0
MS
LIS331DLM Register mapping
Doc ID 15102 Rev 4 23/38
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
Name Type
Register address
Default Comment
Hex Binary
Reserved (do not modify) 00 - 0E Reserved
WHO_AM_I r 0F 000 1111 00010010 Dummy register
Reserved (do not modify) 10 - 1F Reserved
CTRL_REG1 rw 20 010 0000 00000111
CTRL_REG2 rw 21 010 0001 00000000
CTRL_REG3 rw 22 010 0010 00000000
CTRL_REG4 rw 23 010 0011 00000000
CTRL_REG5 rw 24 010 0100 00000000
HP_FILTER_RESET r 25 010 0101 Dummy register
REFERENCE rw 26 010 0110 00000000
STATUS_REG r 27 010 0111 00000000
-- r 28 010 1000 00000000 Not used
OUT_X r 29 010 1001 output
-- r 2A 010 1010 00000000 Not used
OUT_Y r 2B 010 1011 output
-- r 2C 010 1100 00000000 Not used
OUT_Z r 2D 010 1101 output
Reserved (do not modify) 2E - 2F Reserved
INT1_CFG rw 30 011 0000 00000000
INT1_SOURCE r 31 011 0001 00000000
INT1_THS rw 32 011 0010 00000000
INT1_DURATION rw 33 011 0011 00000000
INT2_CFG rw 34 011 0100 00000000
INT2_SOURCE r 35 011 0101 00000000
INT2_THS rw 36 011 0110 00000000
INT2_DURATION rw 37 011 0111 00000000
Reserved (do not modify) 38 - 3F Reserved
Register mapping LIS331DLM
24/38 Doc ID 15102 Rev 4
Registers marked as Reserved must not be changed. The writing to those registers may
cause permanent damages to the device.
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.
LIS331DLM Register description
Doc ID 15102 Rev 4 25/38
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)
Device identification register.
This register contains the device identifier that for LIS331DLM is set to 12h.
7.2 CTRL_REG1 (20h)
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.
Table 16. WHO_AM_I register
00010010
Table 17. CTRL_REG1 register
PM2 PM1 PM0 DR1 DR0 Zen Yen Xen
Table 18. CTRL_REG1 description
PM2 - PM0 Power mode selection. Default value: 000
(000: Power-down; Others: refer to Table 19)
DR1, DR0 Data rate selection. Default value: 00
(00:50 Hz; Others: refer to Table 20)
Zen Z axis enable. Default value: 1
(0: Z axis disabled; 1: Z axis enabled)
Ye n Y axis enable. Default value: 1
(0: Y axis disabled; 1: Y axis enabled)
Xen X axis enable. Default value: 1
(0: X axis disabled; 1: X axis enabled)
Register description LIS331DLM
26/38 Doc ID 15102 Rev 4
7.3 CTRL_REG2 (21h)
Table 19. Power mode and low-power output data rate configurations
PM2 PM1 PM0 Power mode selection Output data rate [Hz]
ODRLP
0 0 0 Power-down -
0 0 1 Normal mode ODR
0 1 0 Low-power 0.5
0 1 1 Low-power 1
1 0 0 Low-power 2
1 0 1 Low-power 5
1 1 0 Low-power 10
Table 20. Normal-mode output data rate configurations and low-pass cut-off
frequencies
DR1(1)
1. “11” bit configuration is not allowed and may cause incorrect device functionality.
DR0(1) Output data rate [Hz]
ODR
Low-pass filter cut-off
frequency [Hz]
00 50 37
01 100 74
1 0 400 292
Table 21. CTRL_REG2 register
BOOT HPM1 HPM0 FDS HPen2 HPen1 HPCF1 HPCF0
Table 22. CTRL_REG2 description
BOOT Reboot memory content. Default value: 0
(0: normal mode; 1: reboot memory content)
HPM1, HPM0 High pass filter mode selection. Default value: 00
(00: normal mode; Others: refer to Table 23)
FDS Filtered data selection. Default value: 0
(0: internal filter bypassed; 1: data from internal filter sent to output register)
HPen2 High pass filter enabled for Interrupt 2 source. Default value: 0
(0: filter bypassed; 1: filter enabled)
LIS331DLM Register description
Doc ID 15102 Rev 4 27/38
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’.
HPCF[1:0]. These bits are used to configure high-pass filter cut-off frequency ft which is
given by:
The equation can be semplified to the following approximated equation:
HPen1 High pass filter enabled for Interrupt 1 source. Default value: 0
(0: filter bypassed; 1: filter enabled)
HPCF1,
HPCF0
High pass filter cut-off frequency configuration. Default value: 00
(00: HPc=8; 01: HPc=16; 10: HPc=32; 11: HPc=64)
Table 23. High-pass filter mode configuration
HPM1 HPM0 High-pass filter mode
0 0 Normal mode (reset reading HP_RESET_FILTER)
0 1 Reference signal for filtering
1 0 Normal mode (reset reading HP_RESET_FILTER)
Table 24. High-pass filter cut-off frequency configuration
HPcoeff2,1 ft [Hz]
Data rate = 50 Hz
ft [Hz]
Data rate = 100 Hz
ft [Hz]
Data rate = 400 Hz
00 1 2 8
01 0.5 1 4
10 0.25 0.5 2
11 0.125 0.25 1
Table 22. CTRL_REG2 description (continued)
ft11
HPc
------------–
⎝⎠
⎛⎞
fs
2π
------
⋅ln=
ft
fs
6HPc⋅
----------------------=
Register description LIS331DLM
28/38 Doc ID 15102 Rev 4
7.4 CTRL_REG3 [Interrupt CTRL register] (22h)
7.5 CTRL_REG4 (23h)
Table 25. CTRL_REG3 register
IHL PP_OD LIR2 I2_CFG1 I2_CFG0 LIR1 I1_CFG1 I1_CFG0
Table 26. CTRL_REG3 description
IHL Interrupt active high, low. Default value: 0
(0: active high; 1: active low)
PP_OD Push-pull/Open drain selection on interrupt pad. Default value 0.
(0: push-pull; 1: open drain)
LIR2
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)
LIR1
Latch interrupt request on INT1_SRC register, with INT1_SRC register cleared by
reading INT1_SRC register. Default value: 0.
(0: interrupt request not latched; 1: interrupt request latched)
I1_CFG1,
I1_CFG0
Data signal on INT 1 pad control bits. Default value: 00.
(see table below)
Table 27. Data signal on INT 1 and INT 2 pad
I1(2)_CFG1 I1(2)_CFG0 INT 1(2) Pad
0 0 Interrupt 1 (2) source
0 1 Interrupt 1 source OR interrupt 2 source
1 0 Data ready
1 1 Boot running
Table 28. CTRL_REG4 register
0 0 FS1 FS0 STsign 0 ST SIM
LIS331DLM Register description
Doc ID 15102 Rev 4 29/38
7.6 CTRL_REG5 (24h)
TurnOn bits are used for turning on the sleep to wake function.
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)
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.
Table 29. CTRL_REG4 description
FS1, FS0 Full-scale selection. Default value: 00.
(00: ±2 g; 01: ±4 g; 11: ±8 g)
STsign Self-test sign. Default value: 00.
(0: self-test plus; 1 self-test minus)
ST Self-test enable. Default value: 0.
(0: self-test disabled; 1: self-test enabled)
SIM SPI serial interface mode selection. Default value: 0.
(0: 4-wire interface; 1: 3-wire interface)
Table 30. CTRL_REG5 register
000000TurnOn1TurnOn0
Table 31. CTRL_REG5 description
Tu rn On 1 ,
Tu r n O n 0 Turn-on mode selection for sleep to wake function. Default value: 00.
Table 32. REFERENCE register
Ref7 Ref6 Ref5 Ref4 Ref3 Ref2 Ref1 Ref0
Table 33. REFERENCE description
Ref7 - Ref0 Reference value for high-pass filter. Default value: 00h.
Register description LIS331DLM
30/38 Doc ID 15102 Rev 4
7.9 STATUS_REG (27h)
7.10 OUT_X (29)
X-axis acceleration data. The value is expressed as two’s complement with 8 bit data
representation right justified.
7.11 OUT_Y (2Bh)
Y-axis acceleration data. The value is expressed as two’s complement with 8 bit data
representation right justified.
7.12 OUT_Z (2Dh)
Z-axis acceleration data. The value is expressed as two’s complement with 8 bit data
representation right justified.
Table 34. STATUS_REG register
ZYXOR ZOR YOR XOR ZYXDA ZDA YDA XDA
Table 35. STATUS_REG description
ZYXOR
X, Y and Z axis data overrun. Default value: 0
(0: no overrun has occurred;
1: new data has overwritten the previous one before it was read)
ZOR
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)
YOR
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)
XOR
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)
ZYXDA X, Y and Z axis new data available. Default value: 0
(0: a new set of data is not yet available; 1: a new set of data is available)
ZDA Z 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)
YDA Y 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)
XDA X 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)
LIS331DLM Register description
Doc ID 15102 Rev 4 31/38
7.13 INT1_CFG (30h)
Configuration register for interrupt 1 source.
Table 36. INT1_CFG register
AOI 6D ZHIE ZLIE YHIE YLIE XHIE XLIE
Table 37. INT1_CFG description
AOI AND/OR combination of Interrupt events. Default value: 0.
(See Table 38)
6D 6 direction detection function enable. Default value: 0.
(See Table 38)
ZHIE
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)
YHIE
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)
YLIE
Enable interrupt generation on Y low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
XHIE
Enable interrupt generation on X high event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
XLIE
Enable interrupt generation on X low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Table 38. Interrupt 1 source configurations
AOI 6D Interrupt mode
0 0 OR combination of interrupt events
0 1 6 direction movement recognition
1 0 AND combination of interrupt events
1 1 6 direction position recognition
Register description LIS331DLM
32/38 Doc ID 15102 Rev 4
7.14 INT1_SRC (31h)
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.
7.15 INT1_THS (32h)
7.16 INT1_DURATION (33h)
Table 39. INT1_SRC register
0 IA ZHZLYHYLXHXL
Table 40. INT1_SRC description
IA Interrupt Active. Default value: 0
(0: no interrupt has been generated; 1: one or more interrupts have been generated)
ZH Z high. Default value: 0
(0: no interrupt, 1: Z High event has occurred)
ZL Z low. Default value: 0
(0: no interrupt; 1: Z Low event has occurred)
YH Y high. Default value: 0
(0: no interrupt, 1: Y High event has occurred)
YL Y low. Default value: 0
(0: no interrupt, 1: Y Low event has occurred)
XH X high. Default value: 0
(0: no interrupt, 1: X High event has occurred)
XL X low. Default value: 0
(0: no interrupt, 1: X Low event has occurred)
Table 41. INT1_THS register
0 THS6 THS5 THS4 THS3 THS2 THS1 THS0
Table 42. INT1_THS description
THS6 - THS0 Interrupt 1 threshold. Default value: 000 0000
Table 43. INT1_DURATION register
0 D6D5D4D3D2D1D0
LIS331DLM Register description
Doc ID 15102 Rev 4 33/38
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)
Configuration register for Interrupt 2 source.
Table 44. INT2_DURATION description
D6 - D0 Duration value. Default value: 000 0000
Table 45. INT2_CFG register
AOI 6D ZHIE ZLIE YHIE YLIE XHIE XLIE
Table 46. INT2_CFG description
AOI AND/OR combination of Interrupt events. Default value: 0.
(See table below)
6D 6 direction detection function enable. Default value: 0.
(See table below)
ZHIE
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)
YHIE
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)
YLIE
Enable interrupt generation on Y low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
XHIE
Enable interrupt generation on X high event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value higher than preset threshold)
XLIE
Enable interrupt generation on X low event. Default value: 0
(0: disable interrupt request;
1: enable interrupt request on measured accel. value lower than preset threshold)
Table 47. Interrupt mode configuration
AOI 6D Interrupt mode
0 0 OR combination of interrupt events
0 1 6 direction movement recognition
Register description LIS331DLM
34/38 Doc ID 15102 Rev 4
7.18 INT2_SRC (35h)
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.
7.19 INT2_THS (36h)
1 0 AND combination of interrupt events
1 1 6 direction position recognition
Table 47. Interrupt mode configuration (continued)
AOI 6D Interrupt mode
Table 48. INT2_SRC register
0 IA ZHZLYHYLXHXL
Table 49. INT2_SRC description
IA Interrupt active. Default value: 0
(0: no interrupt has been generated; 1: one or more interrupts have been generated)
ZH Z high. Default value: 0
(0: no interrupt, 1: Z high event has occurred)
ZL Z low. Default value: 0
(0: no interrupt; 1: Z low event has occurred)
YH Y high. Default value: 0
(0: no interrupt, 1: Y high event has occurred)
YL Y low. Default value: 0
(0: no interrupt, 1: Y low event has occurred)
XH X high. Default value: 0
(0: no interrupt, 1: X high event has occurred)
XL X low. Default value: 0
(0: no interrupt, 1: X low event has occurred)
Table 50. INT2_THS register
0 THS6 THS5 THS4 THS3 THS2 THS1 THS0
Table 51. INT2_THS description
THS6 - THS0 Interrupt 1 threshold. Default value: 000 0000
LIS331DLM Register description
Doc ID 15102 Rev 4 35/38
7.20 INT2_DURATION (37h)
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.
Table 52. INT2_DURATION register
0 D6D5D4D3D2D1D0
Table 53. INT2_DURATION description
D6 - D0 Duration value. Default value: 000 0000
Package information LIS331DLM
36/38 Doc ID 15102 Rev 4
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. mm inch
Min. Typ. Max. Min. Typ. Max.
A1 1.000 0.0394
A2 0.7850.0309
A30.200 0.0079
D1 2.850 3.000 3.150 0.1122 0.1181 0.1240
E1 2.850 3.000 3.150 0.1122 0.1181 0.1240
L1 1.000 1.060 0.0394 0.0417
L2 2.000 2.060 0.07870.0811
N1 0.500 0.0197
N2 1.000 0.0394
M 0.040 0.100 0.160 0.0016 0.0039 0.0063
P1 0.875 0.0344
P2 1.275 0.0502
T1 0.2900.350 0.410 0.0114 0.0138 0.0161
T2 0.190 0.250 0.310 0.0075 0.0098 0.0122
d 0.150 0.0059
k 0.050 0.0020
LGA16 (3x3x1.0mm)
Land Grid Array Package
Outline and
7983231
mechanical data
LIS331DLM Revision history
Doc ID 15102 Rev 4 37/38
9 Revision history
Table 54. Document revision history
Date Revision Changes
16-Oct-2008 1 Initial release
03-Nov-2008 2 Table , 15, 16 have been updated
21-Nov-2008 3 Updated Table 4 on page 10
10-Jul-2009 4
Updated: Table 4 on page 10, Table 6 on page 12, Table 7 on
page 13, Table 28 on page 28, Table 29 on page 29
Minor text changes to improve readability
LIS331DLM
38/38 Doc ID 15102 Rev 4
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