LIS35DETR - STMICROELECTRONICS

April 2009 Doc ID 15594 Rev 1 1/39

LIS35DE

MEMS motion sensor

3-axis - ±2g/±8g smart digital output “piccolo” accelerometer

Feature

■2.16 V to 3.6 V supply voltage

■1.8V compatible IOs

■< 1 mW power consumption

■±2g/±8g dynamically selectable full-scale

■I2C/SPI digital output interface

■Programmable multiple interrupt generator

■Click and double click recognition

■Embedded high pass filter

■10000g high shock survivability

■ECOPACK® RoHS and “Green” compliant

(see Section 8)

Applications

■Free-fall detection

■Motion activated functions

■Gaming and virtual reality input devices

■Vibration monitoring and compensation

Description

The LIS35DE is an ultra compact low-power three

axis linear accelerometer. It includes a sensing

element and an IC interface able to provide the

measured acceleration to the external world

through I2C/SPI serial interface.

The sensing element, capable of detecting the

acceleration, is manufactured using a dedicated

process developed by ST to produce inertial

sensors and actuators in silicon.

The IC interface is manufactured using a CMOS

process that allows to design a dedicated circuit

which is trimmed to better match the sensing

element characteristics.

The LIS35DE has dynamically user selectable full

scales of ±2g/±8g and it is capable of measuring

accelerations with an output data rate of 100 Hz

or 400 Hz.

The device may be configured to generate inertial

wake-up/free-fall interrupt signals when a

programmable acceleration threshold is crossed

at least in one of the three axes. Thresholds and

timing of interrupt generators are programmable

by the end user on the fly.

The LIS35DE is available in plastic Thin Land

Grid Array package (TGA) and it is designed to

operate over an extended temperature range from

-40°C to +85°C.

LGA14

(3x5x0.9mm)

Table 1. Device summary

Order code Temp range, °CPackage Packing

LIS35DE -40 to +85 LGA14 Tray

LIS35DETR -40 to +85 LGA14 Tape and reel

www.st.com

Contents LIS35DE

2/39 Doc ID 15594 Rev 1

Contents

1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Mechanical and electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Communication interface characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.3.1 SPI - serial peripheral interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2.3.2 I2C - Inter IC Control Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.4 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.5 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.5.1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.5.2 Zero-g level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.5.3 Click and double click recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.1 Sensing element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.2 IC interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.3 Factory calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.1 Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5 Digital interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.1 I2C serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.1.1 I2C operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2 SPI bus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.2.1 SPI read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.2 SPI write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.3 SPI read in 3-wires mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6 Register mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

LIS35DE Contents

Doc ID 15594 Rev 1 3/39

7 Register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

7.1 CTRL_REG1 (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

7.2 CTRL_REG2 (21h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.3 CTRL_REG3 [interrupt CTRL register] (22h) . . . . . . . . . . . . . . . . . . . . . . 25

7.4 HP_FILTER_RESET (23h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

7.5 STATUS_REG (27h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7.6 OUT_X (29h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7.7 OUT_Y (2Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

7.8 OUT_Z (2Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

7.9 FF_WU_CFG_1 (30h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

7.10 FF_WU_SRC_1 (31h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

7.11 FF_WU_THS_1 (32h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

7.12 FF_WU_DURATION_1 (33h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

7.13 FF_WU_CFG_2 (34h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

7.14 FF_WU_SRC_2 (35h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

7.15 FF_WU_THS_2 (36h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

7.16 FF_WU_DURATION_2 (37h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

7.17 CLICK_CFG (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

7.18 CLICK_SRC (39h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

7.19 CLICK_THSY_X (3Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

7.20 CLICK_THSZ (3Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

7.21 CLICK_TimeLimit (3Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

7.22 CLICK_Latency (3Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

7.23 CLICK_Window (3Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

8 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

List of tables LIS35DE

4/39 Doc ID 15594 Rev 1

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 2. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 3. Mechanical characteristics @ Vdd=2.5 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 4. Electrical characteristics @ Vdd=2.5 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table 5. SPI slave timing values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 6. I2C slave timing values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 7. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 8. Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 9. Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 10. SAD+Read/Write patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 11. Transfer when Master is writing one byte to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 12. Transfer when Master is writing multiple bytes to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 13. Transfer when Master is receiving (reading) one byte of data from slave . . . . . . . . . . . . . 18

Table 14. Transfer when Master is receiving (reading) multiple bytes of data from slave . . . . . . . . . 18

Table 15. Transfer when Master is receiving (reading) multiple bytes of data from slave . . . . . . . . . 18

Table 16. Register address map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 18. CTRL_REG1 (20h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 19. CTRL_REG2 (21h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 20. CTRL_REG2 (21h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 21. High pass filter cut-off frequency configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 22. CTRL_REG3 [interrupt CTRL register] (22h) register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 23. CTRL_REG3 [interrupt CTRL register] (22h) register description . . . . . . . . . . . . . . . . . . . 26

Table 24. Data signal on Int pad control bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 25. STATUS_REG (27h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 26. STATUS_REG (27h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 27. OUT_X (29h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 28. OUT_Y (2Bh) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 29. OUT_Z (2Dh) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 30. FF_WU_CFG_1 (30h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 31. FF_WU_CFG_1 (30h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 32. FF_WU_SRC_1 (31h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 33. FF_WU_SRC_1 (31h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 34. FF_WU_THS_1 (32h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 35. FF_WU_THS_1 (32h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 36. FF_WU_DURATION_1 (33h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 37. FF_WU_DURATION_1 (33h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 38. FF_WU_CFG_2 (34h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 39. FF_WU_CFG_2 (34h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 40. FF_WU_SRC_2 (35h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 41. FF_WU_SRC_2 (35h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 42. FF_WU_THS_2 (36h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 43. FF_WU_THS_2 (36h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 44. FF_WU_DURATION_2 (37h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 45. FF_WU_DURATION_2 (37h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 46. CLICK_CFG (38h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 47. CLICK_CFG (38h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 48. Click interrupt configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 49. CLICK_SRC (39h) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

LIS35DE List of tables

Doc ID 15594 Rev 1 5/39

Table 50. CLICK_SRC (39h) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 51. CLICK_THSY_X (3Bh) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 52. CLICK_THSY_X (3Bh) register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 53. CLICK_THSZ (3Ch) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 54. CLICK_THSZ (3Ch) register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 55. CLICK_TimeLimit (3Dh) register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 56. CLICK_Latency (3Eh) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 57. CLICK_Window (3Fh) register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 58. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

List of figures LIS35DE

6/39 Doc ID 15594 Rev 1

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 2. Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 3. SPI slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 4. I2C Slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 5. LIS35DE electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 6. Read and write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 7. SPI read protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 8. Multiple bytes SPI Read protocol (2 bytes example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 9. SPI write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 10. Multiple bytes SPI Write protocol (2 bytes example) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 11. SPI read protocol in 3-wires mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 12. LGA14: mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

LIS35DE Block diagram and pin description

Doc ID 15594 Rev 1 7/39

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-

X+

X-

SPI

SCL/SPC

SDA/SDO/SDI

SDO

CONTROL LOGIC

INTERRUPT GEN.

INT 1

CLOCK

TRIMMING

CIRCUITS

REFERENCE

CONTROL LOGIC

A/D

CONVERTER

INT 2

MUX

13 8

BOTTOM VIEW

TOP VIEW

Block diagram and pin description LIS35DE

8/39 Doc ID 15594 Rev 1

Table 2. Pin description

Pin# Name Function

1 Vdd_IO Power supply for I/O pins

2 GND 0V supply

3 Reserved Connect to Vdd

4 GND 0V supply

5 GND 0V supply

6 Vdd Power supply

7CS

SPI enable

I2C/SPI mode selection (1: I2C mode; 0: SPI enabled)

8 INT 1 Inertial interrupt 1

9 INT 2 Inertial interrupt 2

10 GND 0V supply

11 Reserved Connect to Gnd

12 SDO SPI serial data output

I2C less significant bit of the device address

SDA

SDI

SDO

I2C serial data (SDA)

SPI serial data input (SDI)

3-wire interface serial data output (SDO)

14 SCL

SPC

I2C serial clock (SCL)

SPI serial port clock (SPC)

LIS35DE Mechanical and electrical specifications

Doc ID 15594 Rev 1 9/39

2 Mechanical and electrical specifications

2.1 Mechanical characteristics

T = 25°C unless otherwise noted

Table 3. Mechanical characteristics @ Vdd=2.5 V(1)

Symbol Parameter Test conditions Min. Typ.(2) Max. Unit

FS Measurement range FS bit set to 0(3) ±2.0 ±2.3 g

FS bit set to 1 ±9.2

Dres Device resolution FS bit set to 0 72 mg

So Sensitivity FS bit set to 0 15 18 21 mg/digit

FS bit set to 1 61 72 83

TCSO Sensitivity change vs

temperature FS bit set to 0 ±0.01 %/°C

Ty O f f Typical zero-g level offset

accuracy(4)

FS bit set to 0 ±60 mg

FS bit set to 1 ±80 mg

TCOff Zero-g level change vs

temperature Max delta from 25°C ±0.5 mg/°C

BW System bandwidth(5) ODR/2 Hz

Top Operating temperature range -40 +85 °C

Wh Product weight 20 mgram

1. The product is factory calibrated at 2.5 V. The device can be used 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. ODR is output data rate. Refer to Table 4 for specifications.

Mechanical and electrical specifications LIS35DE

10/39 Doc ID 15594 Rev 1

2.2 Electrical characteristics

T = 25°C unless otherwise noted

Table 4. Electrical characteristics @ Vdd=2.5 V (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 Supply current T = 25°C, ODR=100 Hz 0.3 0.45 mA

IddPdn Current consumption in

power-down mode T = 25°C 1 5 µA

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 DR=0 100 Hz

DR=1 400

BW System bandwidth(4) ODR/2 Hz

Ton Turn-on time(5) 3/ODR s

Top Operating temperature range -40 +85 °C

1. The product is factory calibrated at 2.5V. The device can be used 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. Filter cut-off frequency.

5. Time to obtain valid data after exiting power-down mode.

LIS35DE Mechanical and electrical specifications

Doc ID 15594 Rev 1 11/39

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 (a)

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 5

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 6

tdis(SO) SDO output disable time 50

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

a. Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both input and output port

SPC

SDI

SDO

su(CS)

v(SO)

h(SO)

h(SI)

su(SI)

h(CS)

dis(SO)

c(SPC)

MSB IN

MSB OUT LSB OUT

LSB IN

(3)

Mechanical and electrical specifications LIS35DE

12/39 Doc ID 15594 Rev 1

2.3.2 I2C - Inter IC control interface

Subject to general operating conditions for Vdd and top.

Figure 4. I2C Slave timing diagram (b)

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

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

b. Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both port

SDA

SCL

f(SDA)

su(SP)

w(SCLL)

su(SDA)

r(SDA)

su(SR)

h(ST)

w(SCLH)

h(SDA)

r(SCL)

f(SCL)

w(SP:SR)

START

REPEATED

START

STOP

STAR

LIS35DE Mechanical and electrical specifications

Doc ID 15594 Rev 1 13/39

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) -0.3 to Vdd_IO +0.3 V

APOW Acceleration (any axis, powered, Vdd=2.5V) 3000g for 0.5 ms

10000g for 0.1 ms

AUNP Acceleration (any axis, unpowered) 3000g for 0.5 ms

10000g 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 LIS35DE

14/39 Doc ID 15594 Rev 1

2.5 Terminology

2.5.1 Sensitivity

Sensitivity describes the gain of the sensor and can be determined e.g. by applying 1g

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 (point to the sky) and noting the output value again. By doing so,

±1g 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 very little over time. The Sensitivity

Tolerance describes the range of Sensitivities of a large population of sensor.

2.5.2 Zero-g level

Zero-g level Offset (Off) describes the deviation of an actual output signal from the ideal

output signal if there is no acceleration present. A sensor in a steady state on a horizontal

surface will measure 0g in X axis and 0g in Y axis whereas the Z axis will measure 1g. 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 a precise 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 of an individual sensor is stable

over lifetime. The Zero-g level tolerance describes the range of Zero-g levels of a population

of sensors.

2.5.3 Click and double click recognition

The click and double click recognition functions help to create man-machine interface with

little software overload. The device can be configured to output an interrupt signal on

dedicated pin when tapped in any direction.

If the sensor is exposed to a single input stimulus it generates an interrupt request on inertial

interrupt pin (INT1 and/or INT2). A more advanced feature allows to generate and interrupt

request when a “double click” with programmable time between the two events enabling a

“mouse button like” use.

This function can be fully programmed by the user in terms of expected amplitude and

timing of the stimuli.

LIS35DE Functionality

Doc ID 15594 Rev 1 15/39

3 Functionality

The LIS35DE is a ultracompact, 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 sense 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 fF range.

3.2 IC interface

The complete measurement chain is composed by a low-noise capacitive amplifier which

converts into an analog voltage the capacitive unbalancing of the MEMS sensor and by

analog-to-digital converters.

The acceleration data may be accessed through an I2C/SPI interface thus making the

device particularly suitable for direct interfacing with a microcontroller.

The LIS35DE 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 LIS35DE 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 (Off).

The trimming values are stored inside the device by a non volatile memory. Any time the

device is turned on, the trimming parameters are downloaded into the registers to be used

during the normal operation. This allows the user to use the device without further

calibration.

Application hints LIS35DE

16/39 Doc ID 15594 Rev 1

4 Application hints

Figure 5. LIS35DE 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 Al) should be

placed as near as possible to the pin 6 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 busses, 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/SPI interface.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 though 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 recommendation are available at www.st.com.

813

Top VIEW

10uF

Vdd

100nF

GND

Vdd_IO

SDO

SDA/SDI/SDO

INT 1

INT 2

SCL/SPC

Digital signal from/to signal controller.Signal’s levels are defined by proper selection of Vdd_IO

TOP VIEW

DIRECTIONS OF THE

DETECTABLE

ACCELERATIONS

LIS35DE Digital interfaces

Doc ID 15594 Rev 1 17/39

5 Digital interfaces

The registers embedded inside the LIS35DE 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 LIS35DE I2C is a bus slave. The I2C is employed to write the data into the 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 LIS35DE. 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 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)

SDO 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 LIS35DE

18/39 Doc ID 15594 Rev 1

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 LIS35DE is 001110xb. SDO pad can be used to

modify less significant bit of the device address. If SDO pad is connected to voltage supply

LSb is ‘1’ (address 0011101b) else if SDO pad is connected to ground LSb value is ‘0’

(address 0011100b). This solution permits to connect and address two different

accelerometer 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 has

been received.

The I2C embedded inside the LIS35DE behaves like a slave device and the following

protocol must be adhered to. After the start condition (ST) a salve address is sent, once a

slave acknowledge (SAK) has been returned, a 8-bit sub-address 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 is ‘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 transmits to the slave with direction unchanged. Table 10 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] = SDO R/W SAD+R/W

Read 001110 0 1 00111001 (39h)

Write 001110 0 0 00111000 (38h)

Read 001110 1 1 00111011 (3Bh)

Write 001110 1 0 00111010 (3Ah)

Table 11. Transfer when Master is writing one byte to slave

Master ST SAD + W SUB DATA SP

Slave SAK SAK SAK

LIS35DE Digital interfaces

Doc ID 15594 Rev 1 19/39

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 read.

In the presented communication format MAK is Master Acknowledge and NMAK is No

Master Acknowledge.

5.2 SPI bus interface

The LIS35DE 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

Slave SAK SAK SAK DATA

Table 15. Transfer when Master is receiving (reading) multiple bytes of data from

slave

Master MAK NMAK SP

Slave DATA DATA

Digital interfaces LIS35DE

20/39 Doc ID 15594 Rev 1

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 byte 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 drives SDO at the start of bit 8.

bit 1: MS bit. When 0, the address will remains 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 will be 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.

SPC

SDI

SDO

AD5 AD4 AD3 AD2 AD1 AD0

DI7DI6DI5DI4DI3DI2DI1DI0

DO7DO6DO5DO4DO3DO2DO1DO0

LIS35DE Digital interfaces

Doc ID 15594 Rev 1 21/39

5.2.1 SPI read

Figure 7. SPI read protocol

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

SPC

SDI

SDO

DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0

AD5 AD4 AD3 AD2 AD1 AD0

SPC

SDI

SDO

DO7DO6DO5DO4DO3DO2DO1DO0

AD5 AD4 AD3 AD2 AD1 AD0

DO15 DO14 DO13 DO12 DO11 DO10 DO9 DO8

SPC

SDI

RW DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0

AD5 AD4 AD3 AD2 AD1 AD0MS

Digital interfaces LIS35DE

22/39 Doc ID 15594 Rev 1

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 will be written inside the device

(MSb first).

bit 16-... : data DI(...-8). Further data in multiple byte writing.

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_REG2.

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 will be read from the device (MSb

first).

Multiple read command is also available in 3-wires mode.

SPC

SDI

AD5 AD4 AD3 AD2 AD1 AD0

DI7 DI6 DI5 DI4 DI3 DI2 DI1 DI0 DI15 DI14 DI13 DI12 DI11 DI10 DI9 DI8

SPC

SDI/O

RW DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0

AD5 AD4 AD3 AD2 AD1 AD0

LIS35DE Register mapping

Doc ID 15594 Rev 1 23/39

6 Register mapping

The table given below provides a listing of the 8 bit registers embedded in the device and

the related address:

Table 16. Register address map

Name Type

Default Comment

Hex Binary

Reserved (do not modify) 00-1F Reserved

Ctrl_Reg1 rw 20 010 0000 00000111

Ctrl_Reg2 rw 21 010 0001 00000000

Ctrl_Reg3 rw 22 010 0010 00000000

HP_filter_reset r 23 010 0011 dummy Dummy register

Reserved (do not modify) 24-26 Reserved

Status_Reg r 27 010 0111 00000000

-- r 28 010 1000 Not used

OutX r 29 010 1001 output

-- r 2A 010 1010 Not used

OutY r 2B 010 1011 output

-- r 2C 010 1100 Not used

OutZ r 2D 010 1101 output

Reserved (do not modify) 2E-2F Reserved

FF_WU_CFG_1 rw 30 011 0000 00000000

FF_WU_SRC_1(ack1) r 31 011 0001 00000000

FF_WU_THS_1 rw 32 011 0010 00000100

FF_WU_DURATION_1 rw 33 011 0011 00000000

FF_WU_CFG_2 rw 34 011 0100 00000000

FF_WU_SRC_2 (ack2) r 35 011 0101 00000000

FF_WU_THS_2 rw 36 011 0110 00000000

FF_WU_DURATION_2 rw 37 011 0111 00000000

CLICK_CFG rw 38 011 1000 00000000

CLICK_SRC (ack) r 39 011 1001 00000000

-- 3A Not used

CLICK_THSY_X rw 3B 011 1011 00000000

CLICK_THSZ rw 3C 011 1100 00000000

CLICK_TimeLimit rw 3D 011 1101 00000000

24/39 Doc ID 15594 Rev 1

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.

CLICK_Latency rw 3E 011 1110 00000000

CLICK_Window rw 3F 011 1111 00000000

Table 16. Register address map (continued)

Name Type

Default Comment

Hex Binary

LIS35DE Register description

Doc ID 15594 Rev 1 25/39

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 CTRL_REG1 (20h)

DR bit allows to select the data rate at which acceleration samples are produced.

The default value is 0 which corresponds to a data-rate of 100Hz. By changing the content

of DR to “1” the selected data-rate will be set equal to 400Hz.

PD bit allows to turn on the turn the device out of power-down mode. The device is in power-

down mode when PD = “0” (default value after boot). The device is in normal mode when PD

is set to 1.

Zen bit enables the generation of Data Ready signal for Z-axis measurement channel when

set to 1. The default value is 1.

Yen bit enables the generation of Data Ready signal for Y-axis measurement channel when

set to 1. The default value is 1.

Xen bit enables the generation of Data Ready signal for X-axis measurement channel when

set to 1. The default value is 1.

Table 17. CTRL_REG1 (20h) register

DR PD FS 0(1) 0(1)

1. CTRL_REG1[4:3] value is loaded at boot, ‘0’ value must not be changed.

Zen Yen Xen

Table 18. CTRL_REG1 (20h) register description

DR Data rate selection. Default value: 0

(0: 100 Hz output data rate; 1: 400 Hz output data rate)

PD Power Down Control. Default value: 0

(0: power down mode; 1: active mode)

FS Full Scale selection. Default value: 0

(refer to Table 2 for typical full scale value)

Zen Z axis enable. Default value: 1

(0: Z axis disabled; 1: Z axis enabled)

Yen 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)

26/39 Doc ID 15594 Rev 1

7.2 CTRL_REG2 (21h)

SIM bit selects the SPI serial interface mode. When SIM is ‘0’ (default value) the 4-wire

interface mode is selected. The data coming from the device are sent to SDO pad. In 3-wire

interface mode output data are sent to SDA_SDI pad.

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 is 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’.

FDS bit enables (FDS=1) or bypass (FDS=0) the high pass filter in the signal chain of the

sensor

HP_coeff[2:1]. These bits are used to configure high-pass filter cut-off frequency ft.

Table 19. CTRL_REG2 (21h) register

SIM BOOT -- FDS HP_FF_

WU2

HP_FF_

WU1 HP_coeff2 HP_coeff1

Table 20. CTRL_REG2 (21h) register description

SIM SPI Serial Interface Mode selection. Default value: 0

(0: 4-wire interface; 1: 3-wire interface)

BOOT Reboot memory content. Default value: 0

(0: normal mode; 1: reboot memory content)

FDS Filtered Data Selection. Default value: 0

(0: internal filter bypassed; 1: data from internal filter sent to output register)

HP FF_WU2 High Pass filter enabled for FreeFall/WakeUp # 2. Default value: 0

(0: filter bypassed; 1: filter enabled)

HP_FF_WU1 High Pass filter enabled for Free-Fall/Wake-Up #1. Default value: 0

(0: filter bypassed; 1: filter enabled)

HP_coeff2

HP_coeff1

High pass filter cut-off frequency configuration. Default value: 00

(See table below)

Table 21. High pass filter cut-off frequency configuration

HP_coeff2,1 ft (Hz)

(DR=100 Hz)

ft (Hz)

(DR=400 Hz)

00 2 8

01 1 4

LIS35DE Register description

Doc ID 15594 Rev 1 27/39

7.3 CTRL_REG3 [interrupt CTRL register] (22h)

7.4 HP_FILTER_RESET (23h)

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.

10 0.5 2

11 0.25 1

Table 21. High pass filter cut-off frequency configuration (continued)

HP_coeff2,1 ft (Hz)

(DR=100 Hz)

ft (Hz)

(DR=400 Hz)

Table 22. CTRL_REG3 [interrupt CTRL register] (22h) register

IHL PP_OD I2CFG2 I2CFG1 I2CFG0 I1CFG2 I1CFG1 I1CFG0

Table 23. CTRL_REG3 [interrupt CTRL register] (22h) register 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)

I2CFG2

I2CFG1

I2CFG0

Data Signal on Int2 pad control bits. Default value 000.

(see table below)

I1CFG2

I1CFG1

I1CFG0

Data Signal on Int1 pad control bits. Default value 000.

(see table below)

Table 24. Data signal on Int pad control bits

I1(2)_CFG2 I1(2)_CFG1 I1(2)_CFG0 Int1(2) pad

0 0 0 GND

001 FF_WU_1

010 FF_WU_2

0 1 1 FF_WU_1 OR FF_WU_2

1 0 0 Data Ready

1 1 1 Click interrupt

28/39 Doc ID 15594 Rev 1

7.5 STATUS_REG (27h)

7.6 OUT_X (29h)

X axis output data.

7.7 OUT_Y (2Bh)

Table 25. STATUS_REG (27h) register

ZXYOR ZOR YOR XOR ZYXDA ZDA YDA XDA

Table 26. STATUS_REG (27h) register description

ZYXOR

X, Y and Z axis Data Overrun. Default value: 0

(0: no overrun has occurred;

1: new data has over written the previous one before it is 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)

Table 27. OUT_X (29h) register

XD7 XD_6 XD5 XD4 XD3 XD2 XD1 XD0

Table 28. OUT_Y (2Bh) register

YD7 YD6 YD5 YD4 YD3 YD2 YD1 YD0

LIS35DE Register description

Doc ID 15594 Rev 1 29/39

Y axis output data.

7.8 OUT_Z (2Dh)

Z axis output data.

7.9 FF_WU_CFG_1 (30h)

Table 29. OUT_Z (2Dh) register

ZD7 ZD6 ZD5 ZD4 ZD3 ZD2 ZD1 ZD0

Table 30. FF_WU_CFG_1 (30h) register

AOI LIR ZHIE ZLIE YHIE YLIE XHIE XLIE

Table 31. FF_WU_CFG_1 (30h) register description

AOI And/Or combination of Interrupt events. Default value: 0

(0: OR combination of interrupt events; 1: AND combination of interrupt events)

LIR

Latch Interrupt request into FF_WU_SRC reg with the FF_WU_SRC reg cleared by

reading FF_WU_SRC_1 reg. Default value: 0

(0: interrupt request not latched; 1: interrupt request latched)

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)

30/39 Doc ID 15594 Rev 1

7.10 FF_WU_SRC_1 (31h)

Free-fall and wake-up source register. Read only register.

Reading at this address clears FF_WU_SRC_1 register and the FF, WU 1 interrupt and

allows the refreshment of data in the FF_WU_SRC_1 register if the latched option is

chosen.

7.11 FF_WU_THS_1 (32h)

Most significant bit (DCRM) is used to select the resetting mode of the duration counter.

If DCRM=0 counter is resetted when the interrupt is no more active else if DCRM=1 duration

counter is decremented.

Table 32. FF_WU_SRC_1 (31h) register

X IA ZHZLYHYLXHXL

Table 33. FF_WU_SRC_1 (31h) register description

IA Interrupt Active. Default value: 0

(0: no interrupt has been generated; 1: one ore more interrupt has been generated)

ZH Z High. Default value: 0

(0: no interrupt, 1: ZH event has occurred)

ZL Z Low. Default value: 0

(0: no interrupt; 1: ZL event has occurred)

YH Y High. Default value: 0

(0: no interrupt, 1: YH event has occurred)

YL Y Low. Default value: 0

(0: no interrupt, 1: YL event has occurred)

XH X High. Default value: 0

(0: no interrupt, 1: XH event has occurred)

XL X Low. Default value: 0

(0: no interrupt, 1: XL event has occurred)

Table 34. FF_WU_THS_1 (32h) register

DCRM THS6 THS5 THS4 THS3 THS2 THS1 THS0

Table 35. FF_WU_THS_1 (32h) register description

DCRM Resetting mode selection. Default value: 0

(0: counter resetted; 1: counter decremented)

THS6, THS0 Free-fall / wake-up Threshold: default value: 000 0100

LIS35DE Register description

Doc ID 15594 Rev 1 31/39

7.12 FF_WU_DURATION_1 (33h)

Duration register for Free-Fall/Wake-Up interrupt 1. Duration step and maximum value

depend on the ODR chosen. Step 2.5 msec, from 0 to 637.5 msec if ODR=400Hz, else step

10 msec, from 0 to 2.55 sec when ODR=100Hz. The counter used to implement duration

function is blocked when LIR=1 in configuration register and the interrupt event is verified

7.13 FF_WU_CFG_2 (34h)

Table 36. FF_WU_DURATION_1 (33h) register

D7 D6 D5 D4 D3 D2 D1 D0

Table 37. FF_WU_DURATION_1 (33h) register description

D7 - D0 Duration value. Default value: 0000 0000

Table 38. FF_WU_CFG_2 (34h) register

AOI LIR ZHIE ZLIE YHIE YLIE XHIE XLIE

Table 39. FF_WU_CFG_2 (34h) register description

AOI And/Or combination of Interrupt events. Default value: 0

(0: OR combination of interrupt events; 1: AND combination of interrupt events)

LIR Latch Interrupt request into FF_WU_SRC reg with the FF_WU_SRC reg cleared by

reading FF_WU_SRC_2 reg. Default value: 0

(0: interrupt request not latched; 1: interrupt request latched)

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)

32/39 Doc ID 15594 Rev 1

7.14 FF_WU_SRC_2 (35h)

Free-fall and wake-up source register. Read only register.

Reading at this address clears FF_WU_SRC_2 register and the FF, WU 2 interrupt and

allows the refreshment of data in the FF_WU_SRC_2 register if the latched option is

chosen.

7.15 FF_WU_THS_2 (36h)

Most significant bit (DCRM) is used to select the resetting mode of the duration counter. If

DCRM=0 counter is resetted when the interrupt is no more active else if DCRM=1 duration

counter is decremented.

Table 40. FF_WU_SRC_2 (35h) register

X IA ZHZLYHYLXHXL

Table 41. FF_WU_SRC_2 (35h) register description

IA Interrupt Active. Default value: 0

(0: no interrupt has been generated;

1: one or more interrupt event has been generated)

ZH Z High. Default value: 0

(0: no interrupt; 1: ZH event has occurred)

ZL Z Low. Default value: 0

(0: no interrupt; 1: ZL event has occurred)

YH Y High. Default value: 0

(0: no interrupt; 1: YH event has occurred)

YL Y Low. Default value: 0

(0: no interrupt; 1: YL event has occurred)

XH X High. Default value: 0

(0: no interrupt; 1: XH event has occurred)

XL X Low. Default value: 0

(0: no interrupt; 1: XL event has occurred)

Table 42. FF_WU_THS_2 (36h) register

DCRM THS6 THS5 THS4 THS3 THS2 THS1 THS0

Table 43. FF_WU_THS_2 (36h) register description

DCRM Resetting mode selection. Default value: 0

(0: counter resetted; 1: counter decremented)

THS6, THS0 Free-fall / wake-up Threshold. Default value: 000 0000

LIS35DE Register description

Doc ID 15594 Rev 1 33/39

7.16 FF_WU_DURATION_2 (37h)

Duration register for Free-Fall/Wake-Up interrupt 2. Duration step and maximum value

depend on the ODR chosen. Step 2.5 msec, from 0 to 637.5 msec if ODR=400Hz, else step

10 msec, from 0 to 2.55 sec when ODR=100Hz. The counter used to implement duration

function is blocked when LIR=1 in configuration register and the interrupt event is verified.

Table 44. FF_WU_DURATION_2 (37h) register

D7 D6 D5 D4 D3 D2 D1 D0

Table 45. FF_WU_DURATION_2 (37h) register description

D7 - D0 Duration value. Default value: 0000 0000

34/39 Doc ID 15594 Rev 1

7.17 CLICK_CFG (38h)

Table 46. CLICK_CFG (38h) register

- LIR Double_Z Single_Z Double_Y Single_Y Double_X Single_X

Table 47. CLICK_CFG (38h) register description

LIR

Latch Interrupt request into CLICK_SRC reg with the CLICK_SRC reg

refreshed by reading CLICK_SRC reg. Default value: 0

(0: interrupt request not latched; 1: interrupt request latched)

Double_Z Enable interrupt generation on double click event on Z axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Single_Z Enable interrupt generation on single click event on Z axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Double_Y Enable interrupt generation on double click event on Y axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Single_Y Enable interrupt generation on single click event on Y axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Double_X Enable interrupt generation on double click event on X axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Single_X Enable interrupt generation on single click event on X axis. Default value: 0

(0: disable interrupt request; 1: enable interrupt request)

Table 48. Click interrupt configurations

Double_Z / Y / X Single_Z / Y / X Click output

00 0

01Single

1 0 Double

1 1 Single OR Double

LIS35DE Register description

Doc ID 15594 Rev 1 35/39

7.18 CLICK_SRC (39h)

7.19 CLICK_THSY_X (3Bh)

From 0.5g (0001) to 7.5g (1111) with step of 0.5g.

7.20 CLICK_THSZ (3Ch)

Table 49. CLICK_SRC (39h) register

X IA Double_Z Single_Z Double_Y Single_Y Double_X Single_X

Table 50. CLICK_SRC (39h) register description

Interrupt Active. Default value: 0

(0: no interrupt has been generated;

1: one or more interrupt event has been generated)

Double_Z Double click on Z axis event. Default value: 0

(0: no interrupt; 1: Double Z event has occurred)

Single_Z Single click on Z axis event. Default value: 0

(0: no interrupt; 1: Single Z event has occurred)

Double_Y Double click on Y axis event. Default value: 0

(0: no interrupt; 1: Double Y event has occurred)

Single_Y Single click on Y axis event.Default value: 0

(0: no interrupt; 1: Single Y event has occurred)

Double_X Double click on X axis event. Default value: 0

(0: no interrupt; 1: Double X event has occurred)

Single_X Single click on X axis event. Default value: 0

(0: no interrupt; 1: Single X event has occurred)

Table 51. CLICK_THSY_X (3Bh) register

THSy3 THSy2 THSy1 THSy0 THSx3 THSx2 THSx1 THSx0

Table 52. CLICK_THSY_X (3Bh) register description

THSy3 - THSy0 Click Threshold on Y axis. Default value: 0000

THSx3 - THSx0 Click Threshold on X axis. Default value: 0000

Table 53. CLICK_THSZ (3Ch) register

XXXXTHSz3THSz2THSz1THSz0

36/39 Doc ID 15594 Rev 1

From 0.5g (0001) to 7.5g (1111) with step of 0.5g.

7.21 CLICK_TimeLimit (3Dh)

From 0 to 127.5msec with step of 0.5msec.

7.22 CLICK_Latency (3Eh)

From 0 to 255 msec with step of 1 msec.

7.23 CLICK_Window (3Fh)

From 0 to 255 msec with step of 1 msec.

Table 54. CLICK_THSZ (3Ch) register description

THSz3 - THSz0 Click Threshold on Z axis. Default value: 0000

Table 55. CLICK_TimeLimit (3Dh) register

Dur7 Dur6 Dur5 Dur4 Dur3 Dur2 Dur1 Dur0

Table 56. CLICK_Latency (3Eh) register

Lat7 Lat6 Lat5 Lat4 Lat3 Lat2 Lat1 Lat0

Table 57. CLICK_Window (3Fh) register

Win7 Win6 Win5 Win4 Win3 Win2 Win1 Win0

LIS35DE Package information

Doc ID 15594 Rev 1 37/39

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. LGA14: mechanical data and package dimensions

OUTLINE AND

MECHANICAL DATA

DIM.

mm inch

MIN. TYP. MAX. MIN. TYP. MAX.

A1 0.920 1.000 0.0362 0.0394

A2 0.700 0.0275

A3 0.180 0.220 0.260 0.0071 0.0087 0.0102

D1 2.850 3.000 3.150 0.1122 0.1181 0.1240

E1 4.850 5.000 5.150 0.1909 0.1968 0.2027

e 0.800 0.0315

d 0.300 0.0118

L1 4.000 0.1575

N 1.360 0.0535

N1 1.200 0.0472

P1 0.965 0.975 0.985 0.0380 0.0384 0.0386

P2 0.640 0.650 0.660 0.0252 0.0256 0.0260

T1 0.750 0.800 0.850 0.0295 0.0315 0.0335

T2 0.450 0.500 0.550 0.0177 0.0197 0.0217

R 1.200 1.600 0.0472 0.0630

h 0.150 0.0059

k 0.050 0.0020

i 0.100 0.0039

s 0.100 0.0039

LGA14 (3x5x0.92mm) Pitch 0.8mm

Land Grid Array Package

7773587 C

Revision history LIS35DE

38/39 Doc ID 15594 Rev 1

9 Revision history

Table 58. Document revision history

Date Revision Changes

29-Apr-2009 1 Initial release

LIS35DE

Doc ID 15594 Rev 1 39/39

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