AIS2DW12TR

MEMS Accelerometer, ± 2g, ± 4g, X, Y, Z, I2C, SPI, LGA, 12 Pins

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Manufacturer: STMICROELECTRONICS
Product type: MEMS Accelerometers
MSL: MSL 3 - 168 hours
SVHC: Lead (21-Jan-2025)
No. of Pins: 12Pins
Sensing Axis: X, Y, Z
Product Range: -
Qualification: AEC-Q100
Sensitivity Max: 0.28mg/digit, 0.56mg/digit, 1.12mg/digit, 2.24mg/digit
Sensitivity Min: 0.21mg/digit, 0.41mg/digit, 0.82mg/digit, 1.65mg/digit
Sensitivity Typ: 0.24mg/digit, 0.48mg/digit, 0.97mg/digit, 1.95mg/digit
Output Interface: I2C, SPI
Sensor Case Style: LGA
MEMS Sensor Output: Digital
Supply Voltage Max: 3.6V
Supply Voltage Min: 1.62V
Sensor Case / Package: LGA
Operating Temperature Max: 85°C
Operating Temperature Min: -40°C
Sensing Range - Accelerometer: ± 2g, ± 4g
Automotive Qualification Standard: AEC-Q100
Delivery and price
Units per pack	1000
Price	1.39 €
Current stock	1000+
Lead time	30 days
Datasheet
## **AIS2DW12** 

## MEMS digital output motion sensor: ultra-low-power 3-axis accelerometer for automotive applications 

**Datasheet** - **production data** 

## **Description** 

The AIS2DW12 is an ultra-low-power three-axis linear accelerometer which leverages on the robust and mature manufacturing processes already used for the production of micromachined accelerometers and designed to address nonsafety automotive applications. 

**LGA-12 (2x2x0.93 mm³)** 

## **Features** 

- AEC-Q100 qualified 

- Supply voltage, 1.62 V to 3.6 V 

- Independent IO supply and supply voltage compatible 

- Ultra-low-power mode consumption down to 380 nA @1.6 Hz 

- ±2 _g_ /±4 _g_ dynamically selectable full scales 

- High-speed I²C/SPI digital output interface 

- 2 independent programmable interrupts 

- Single data conversion on demand 

- 16-bit data output 

- Embedded temperature sensor 

- Self-test 

- 32-level embedded FIFO 

- 10000 _g_ high shock survivability 

- ECOPACK, RoHS and “Green” compliant 

## **Applications** 

- Car key applications 

- Inclination / orientation detection 

The AIS2DW12 has four different ultra-low-power modes, two user-selectable full scales (2 _g_ /4 _g)_ and is capable of measuring accelerations with output data rates from 1.6 Hz to 100 Hz. 

The AIS2DW12 has an integrated 32-level first-in, first-out (FIFO) buffer allowing the user to store data in order to limit intervention by the host processor. 

The embedded self-test capability allows the user to check the functioning of the sensor in the final application. 

The AIS2DW12 has a dedicated internal engine to process motion and acceleration detection including free-fall, motion and no-motion, wakeup, activity/inactivity and 6D/4D orientation. 

The AIS2DW12 is available in a small thin plastic land grid array package (LGA) and it is guaranteed to operate over an extended temperature range from -40 °C to +85 °C. 

**Table 1. Device summary** 

|**Order codes**|**Temp. range**<br>**[**°**C]**|**Package**|**Packaging**|
|---|---|---|---|
|AIS2DW12|-40 to +85|LGA-12|Tray|
|AIS2DW12TR|-40 to +85|LGA-12|Tape and<br>reel|



- Motion-activated functions 

- Gesture recognition 

- Free-fall detection 

- Smart power saving 

1/60 

June 2019 

DocID031240 Rev 4 

This is information on a product in full production. 

_www.st.com_ 

**Contents** 

**AIS2DW12** 

## **Contents** 

|**1**|**Block**|**diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8**|
|---|---|---|
||1.1|Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8|
||1.2|Pin description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9|
|**2**|**Mechanical and electrical specifications  . . . . . . . . . . . . . . . . . . . . . . . 11**||
||2.1|Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11|
||2.2|Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12|
||2.3|Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13|
||2.4|Communication interface characteristics  . . . . . . . . . . . . . . . . . . . . . . . . . 14|
|||2.4.1<br>SPI - serial peripheral interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14|
|||2.4.2<br>I²C - inter-IC control interface  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15|
||2.5|Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17|
|**3**|**Terminology and functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18**||
||3.1|Terminology  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18|
|||3.1.1<br>Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18|
|||3.1.2<br>Zero-g level offset  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18|
||3.2|Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19|
|||3.2.1<br>Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19|
|||3.2.2<br>Single data conversion on-demand mode . . . . . . . . . . . . . . . . . . . . . . . 19|
|||3.2.3<br>Self-test  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20|
|||3.2.4<br>Activity/Inactivity, stationary/motion detection functions . . . . . . . . . . . . . 20|
|||3.2.5<br>Offset management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21|
||3.3|Sensing element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21|
||3.4|IC interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22|
||3.5|Factory calibration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22|
||3.6|Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22|
|**4**|**Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23**||
|**5**|**Digital main blocks  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25**||
||5.1|Block diagram of filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25|
||5.2|FIFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26|
|2/60||DocID031240 Rev 4|



DocID031240 Rev 4 

|**AIS2DW12**||**Contents**|
|---|---|---|
|||5.2.1<br>Bypass mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27|
|||5.2.2<br>FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27|
|||5.2.3<br>Continuous mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27|
|||5.2.4<br>Continuous-to-FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28|
|||5.2.5<br>Bypass-to-Continuous mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29|
|**6**|**Digital interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30**||
||6.1|I²C serial interface  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30|
|||6.1.1<br>I2C operation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31|
||6.2|SPI bus interface  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33|
|||6.2.1<br>SPI read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34|
|||6.2.2<br>SPI write  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35|
|||6.2.3<br>SPI read in 3-wire mode  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36|
|**7**|**Register mapping  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37**||
|**8**|**Register description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39**||
||8.1|OUT_T_L (0Dh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
||8.2|OUT_T_H (0Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
||8.3|WHO_AM_I (0Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
||8.4|CTRL1 (20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
||8.5|CTRL2 (21h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41|
||8.6|CTRL3 (22h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42|
||8.7|CTRL4_INT1 (23h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43|
||8.8|CTRL5_INT2 (24h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44|
||8.9|CTRL6 (25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
||8.10|OUT_T (26h)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|
||8.11|STATUS (27h)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|
||8.12|OUT_X_L (28h)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
||8.13|OUT_X_H (29h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
||8.14|OUT_Y_L (2Ah)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
||8.15|OUT_Y_H (2Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
||8.16|OUT_Z_L (2Ch)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
||8.17|OUT_Z_H (2Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
||8.18|FIFO_CTRL (2Eh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|



3/60 

DocID031240 Rev 4 

**Contents** 

**AIS2DW12** 

||8.19|FIFO_SAMPLES (2Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|---|---|---|
||8.20|SIXD_THS (30h)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
||8.21|WAKE_UP_THS (34h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
||8.22|WAKE_UP_DUR (35h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
||8.23|FREE_FALL (36h)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51|
||8.24|STATUS_DUP (37h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52|
||8.25|WAKE_UP_SRC (38h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
||8.26|SIXD_SRC (3Ah)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
||8.27|ALL_INT_SRC (3Bh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
||8.28|X_OFS_USR (3Ch)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
||8.29|Y_OFS_USR (3Dh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
||8.30|Z_OFS_USR (3Eh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
||8.31|CTRL7 (3Fh)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
|**9**|**Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56**||
||9.1|Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56|
||9.2|LGA-12 package information  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56|
||9.3|LGA-12 packing information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57|
|**10**|**Revision history  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59**||



4/60 

DocID031240 Rev 4 

**AIS2DW12** 

**List of tables** 

## **List of tables** 

|Table|1.|Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1|
|---|---|---|
|Table|2.|Pin description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9|
|Table|3.|Internal pull-up values (typ.) for SDO/SA0 and CS pins . . . . . . . . . . . . . . . . . . . . . . . . . . . 10|
|Table|4.|Mechanical characteristics @ Vdd = 3.0 V, T = -40°C to +85°C unless otherwise noted  . 11|
|Table|5.|Electrical characteristics @ Vdd = 3.0 V, T = -40°C to +85°C unless otherwise noted . . . 12|
|Table|6.|Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13|
|Table|7.|SPI slave timing values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14|
|Table|8.|I²C slave timing values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15|
|Table|9.|I²C high-speed mode specifications at 1 MHz and 3.4 MHz. . . . . . . . . . . . . . . . . . . . . . . . 16|
|Table|10.|Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17|
|Table|11.|Operating modes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19|
|Table|12.|Internal pin status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24|
|Table|13.|Serial interface pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30|
|Table|14.|I²C terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30|
|Table|15.|SAD+Read/Write patterns  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31|
|Table|16.|Transfer when master is writing one byte to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32|
|Table|17.|Transfer when master is writing multiple bytes to slave . . . . . . . . . . . . . . . . . . . . . . . . . . . 32|
|Table|18.|Transfer when master is receiving (reading) one byte of data from slave  . . . . . . . . . . . . . 32|
|Table|19.|Transfer when master is receiving (reading) multiple bytes of data from slave . . . . . . . . . 32|
|Table|20.|Register map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37|
|Table|21.|OUT_T_L register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
|Table|22.|OUT_T_L register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
|Table|23.|OUT_T_H register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
|Table|24.|OUT_T_H register description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
|Table|25.|WHO_AM_I register default values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39|
|Table|26.|Control register 1  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
|Table|27.|Control register 1 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
|Table|28.|Data rate configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
|Table|29.|Operating mode selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
|Table|30.|Power mode selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40|
|Table|31.|Control register 2  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41|
|Table|32.|Control register 2 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41|
|Table|33.|Control register 3  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42|
|Table|34.|Control register 3 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42|
|Table|35.|Self-test mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42|
|Table|36.|Control register 4  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43|
|Table|37.|Control register 4 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43|
|Table|38.|Control register 5  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44|
|Table|39.|Control register 5 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44|
|Table|40.|Control register 6  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|41.|Control register 6 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|42.|Digital filtering cutoff selection (FDS bit set to ‘0’). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|43.|LPF1 cutoff (FDS bit set to '0') . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|44.|Digital high-pass filter cutoff selection (FDS bit set to ‘1’) . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|45.|Full-scale selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45|
|Table|46.|OUT_T register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|
|Table|47.|OUT_T register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|
|Table|48.|STATUS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|



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**List of tables** 

**AIS2DW12** 

|Table|49.|STATUS register description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46|
|---|---|---|
|Table|50.|OUT_X_L register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
|Table|51.|OUT_X_H register  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
|Table|52.|OUT_Y_L register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
|Table|53.|OUT_Y_H register  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47|
|Table|54.|OUT_Z_L register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
|Table|55.|OUT_Z_H register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
|Table|56.|FIFO_CTRL register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
|Table|57.|FIFO_CTRL register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
|Table|58.|FIFO mode selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48|
|Table|59.|FIFO_SAMPLES register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|Table|60.|FIFO_SAMPLES register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|Table|61.|SIXD_THS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|Table|62.|SIXD_THS register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|Table|63.|4D/6D threshold setting FS @ ±2 g  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49|
|Table|64.|WAKE_UP_THS register  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
|Table|65.|WAKE_UP_THS register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
|Table|66.|WAKE_UP_DUR register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
|Table|67.|WAKE_UP_DUR register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50|
|Table|68.|FREE_FALL register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51|
|Table|69.|FREE_FALL register description  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51|
|Table|70.|FREE_FALL threshold decoding @ ±2 g FS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51|
|Table|71.|STATUS_DUP register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52|
|Table|72.|STATUS_DUP register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52|
|Table|73.|WAKE_UP_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
|Table|74.|WAKE_UP_SRC register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
|Table|75.|SIXD_SRC register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
|Table|76.|SIXD_SRC register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53|
|Table|77.|ALL_INT_SRC register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|78.|ALL_INT_SRC register description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|79.|X_OFS_USR register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|80.|X_OFS_USR register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|81.|Y_OFS_USR register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|82.|Y_OFS_USR register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54|
|Table|83.|Z_OFS_USR register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
|Table|84.|Z_OFS_USR register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
|Table|85.|CTRL7 register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
|Table|86.|CTRL7 register description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55|
|Table|87.|Reel dimensions for carrier tape of LGA-12 package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58|
|Table|88.|Document revision history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59|



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**List of figures** 

## **List of figures** 

|Figure|1.|Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8|
|---|---|---|
|Figure|2.|Pin connections  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9|
|Figure|3.|SPI slave timing diagram  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14|
|Figure|4.|I²C slave timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15|
|Figure|5.|Single data conversion on demand functionality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20|
|Figure|6.|AIS2DW12 electrical connections (top view)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23|
|Figure|7.|Accelerometer chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25|
|Figure|8.|Continuous-to-FIFO mode  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28|
|Figure|9.|Trigger event to FIFO for Continuous-to-FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28|
|Figure|10.|Bypass-to-Continuous mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29|
|Figure|11.|Trigger event to FIFO for Bypass-to-Continuous mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 29|
|Figure|12.|Read and write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33|
|Figure|13.|SPI read protocol  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34|
|Figure|14.|Multiple byte SPI read protocol (2-byte example). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34|
|Figure|15.|SPI write protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35|
|Figure|16.|Multiple byte SPI write protocol (2-byte example). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35|
|Figure|17.|SPI read protocol in 3-wire mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36|
|Figure|18.|LGA-12 2.0 x 2.0 x 0.93 mm package outline and mechanical data. . . . . . . . . . . . . . . . . . 56|
|Figure|19.|Carrier tape information for LGA-12 package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57|
|Figure|20.|LGA-12 package orientation in carrier tape  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57|
|Figure|21.|Reel information for carrier tape of LGA-12 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58|



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**Block diagram and pin description** 

## **1 Block diagram and pin description** 

## **1.1 Block diagram** 

**Figure 1. Block diagram** 

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**Block diagram and pin description** 

## **1.2 Pin description** 

**Figure 2. Pin connections** 

**Table 2. Pin description** 

|||**Table 2. Pin description**|
|---|---|---|
|**Pin#**|**Name**|**Function**|
|1|SCL<br>SPC|I2C serial clock (SCL)<br>SPI serial port clock (SPC)|
|2(1)|CS|SPI enable<br>I2C/SPI mode selection (1: SPI idle mode / I2C communication<br>enabled; 0: SPI communication mode / I2C disabled)|
|3(1)|SDO<br>SA0|SPI serial data output (SDO)<br>I2C less significant bit of the device address (SA0)|
|4|SDA<br>SDI<br>SDO|I2C serial data (SDA)<br>SPI serial data input (SDI)<br>3-wire interface serial data output (SDO)|
|5|NC|Internally not connected. Can be tied to VDD, VDDIO, or GND.|
|6|GND|0 V supply|
|7|RES|Connect to GND|
|8|GND|0 V supply|
|9|VDD|Power supply|
|10|VDD_IO|Power supply for I/O pins|
|11|INT2|Interrupt pin 2. Clock input when selected in single data<br>conversion on demand.|
|12|INT1|Interrupt pin 1|



1. SDO/SA0 and CS pins are internally pulled up. Refer to _Table 3_ for the internal pull-up values (typ). 

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**Block diagram and pin description** 

**Table 3. Internal pull-up values (typ.) for SDO/SA0 and CS pins** 

|**Vdd_IO**|**Resistor value for SDO/SA0 and CS pins**|
|---|---|
||**Typ. (k**Ω**)**|
|1.7 V|54.4|
|1.8 V|49.2|
|2.5 V|30.4|
|3.6 V|20.4|



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**Mechanical and electrical specifications** 

## **2 Mechanical and electrical specifications** 

## **2.1 Mechanical characteristics** 

**Table 4. Mechanical characteristics @ Vdd = 3.0 V, T = -40°C to +85°C unless otherwise noted[(1)]** 

|**Symbol**|**Parameter**|**Test conditions**|**Min.**|**Typ.(2)**|**Max.**|**Unit**|
|---|---|---|---|---|---|---|
|FS|Measurement range|||±2||_g_|
|||||±4|||
|So|Sensitivity (long term)(3)|@ FS ±2_g_<br>For all power modes<br>except Mode 1|0.207|0.244|0.281|m_g_/digit|
|||@ FS ±4_g_<br>For all power modes<br>except Mode 1|0.415|0.488|0.561||
|||@ FS ±2_g_<br>in Power Mode 1|0.829|0.976|1.122||
|||@ FS ±4_g_<br>in Power Mode 1|1.659|1.952|2.245||
|RMS|RMS noise(4)<br>@ FS ±2_g_|Power Mode 4||1.6|2.9|m_g_(RMS)|
|||Power Mode 3||2.1|3.8||
|||Power Mode 2||3.0|5.7||
|||Power Mode 1||5.5|11.0||
|TyOff|Zero-_g_level offset accuracy(5)|||±20||m_g_|
||Zero-_g_level offset accuracy, long term(3)||-700||700||
|TCO|Zero-_g_offset change vs. temperature|||±0.2||m_g_/°C|
|TCS|Sensitivity change vs. temperature|||0.01||%/°C|
|ST|Self-test positive difference|@ 25°C|70||1500|m_g_|



1. The product is factory calibrated at 3.0 V. The operational power supply range is from 1.62 V to 3.6 V. 

2. Typical specifications are not guaranteed. 

3. Long term includes the following contributions: post solder, drift in temperature in the range [-40 deg; +85 deg] and over life. 

4. RMS noise is the same for all ODRs, max values from design and characterization at ambient temperature 

5. Values after factory calibration test and trimming. 

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## **2.2 Electrical characteristics** 

**Table 5. Electrical characteristics @ Vdd = 3.0 V, T = -40°C to +85°C unless otherwise noted[(1)]** 

|**Symbol**|**Parameter**|**Test conditions**|**Min.**|**Typ.(2)**|**Max.**|**Unit**|
|---|---|---|---|---|---|---|
|Vdd|Supply voltage||1.62||3.6|V|
|Vdd_IO|I/O pins supply voltage(3)||1.62||Vdd+0.1|V|
|IddLP|Current consumption in<br>Power Mode 1|ODR 100 Hz<br>@ Vdd = 1.8 V(4)||5||μA|
|||ODR 50 Hz<br>@ Vdd = 1.8 V(4)||3|||
|||ODR 12.5 Hz<br>@ Vdd = 1.8 V(4)||1|||
|||ODR 1.6 Hz<br>@Vdd = 1.8 V(4)||0.38|||
|||ODR 100 Hz<br>@ Vdd = 3 V||6.5|12.0||
|||ODR 50 Hz<br>@ Vdd = 3 V(4)||3.7|6.4||
|||ODR 12.5 Hz<br>@ Vdd = 3 V(4)||1.3|2.9||
|||ODR 1.6 Hz<br>@ Vdd = 3 V(4)||0.67|1.9||
|Idd_PD|Current consumption<br>in power-down|@ Vdd = 1.8 V(4)||50||nA|
|||@ Vdd = 3 V||100|950||
|VIH|Digital high-level input voltage||0.8*Vdd_IO|||V|
|VIL|Digital low-level input voltage||||0.2*Vdd_IO|V|
|VOH|Digital high-level output voltage|IOH= 4 mA(5)|VDD_IO - 0.2 V||||
|VOL|Digital low-level output voltage|IOL= 4 mA(5)|||0.2 V||



1. The product is factory calibrated at 3.0 V. The operational power supply range is from 1.62 V to 3.6 V. 

2. Typical specifications 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. Verified at characterization level in Power Mode 1 configuration. 

5. 4 mA is the maximum driving capability, ie. the maximum DC current that can be sourced/sunk by the digital pad in order to guarantee the correct digital output voltage levels VOH and VOL. 

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**Mechanical and electrical specifications** 

## **2.3 Temperature sensor characteristics** 

@ Vdd = 1.8 V, T = 25 °C unless otherwise noted 

**Table 6. Temperature sensor characteristics** 

|**Symbol**|**Parameter**|**Min.**|**Typ.(1)**|**Max.**|**Unit**|
|---|---|---|---|---|---|
|Top|Operating temperature range|-40||+85|°C|
|Toff|Temperature offset(2)|-15||+15|°C|
|TSDr|Temperature sensor output change vs. temperature||1(3)||LSB/°C|
||||16(4)|||
|TODR|Temperature refresh rate for ODRs equal to 100Hz and 50 Hz||50||Hz|
||Temperature refresh rate for ODR equal to 25 Hz||25|||
||Temperature refresh rate for ODR equal to 12.5 Hz||12.5|||
||Temperature refresh rate for ODR equal to 1.6 Hz||1.6|||



1. Typical specifications are not guaranteed. 

2. The output of the temperature sensor is 0 LSB (typ.) at 25 °C. 

3. 8-bit resolution. 

4. 12-bit resolution. 

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## **2.4 Communication interface characteristics** 

## **2.4.1 SPI - serial peripheral interface** 

Subject to general operating conditions for Vdd and Top. 

**Table 7. SPI slave timing values** 

|**Symbol**|**Parameter**|**Value(1)**|**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|12|||
|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||



1. 10 MHz clock frequency for SPI with both 4 and 3 wires, based on characterization results, not tested in production. 

**Figure 3. SPI slave timing diagram** 

_Note: Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both input and output ports._ 

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**Mechanical and electrical specifications** 

## **2.4.2 I²C - inter-IC control interface** 

Subject to general operating conditions for Vdd and Top. 

**Table 8. I²C slave timing values** 

|**Symbol**|**Parameter**|**I2C standard mode (1)**|**I2C standard mode (1)**|**I2C fast mode (1)**|**I2C fast mode (1)**|**Unit**|
|---|---|---|---|---|---|---|
|||**Min**|**Max**|**Min**|**Max**||
|f(SCL)<br>SCL clock frequency|SCL clock frequency|0|100|0|400|kHz|
|tw(SCLL)<br>SCL clock low time|SCL clock low time|4.7||1.3||μs|
|tw(SCLH)<br>SCL clock high time|SCL clock high time|4.0||0.6|||
|tsu(SDA)<br>SDA setup time|SDA setup time|250||100||ns|
|th(SDA)<br>SDA data hold time|SDA data hold time|0.01|3.45|0.01|0.9|μs|
|th(ST)<br>START condition hold time|START condition hold time|4||0.6||μs|
|tsu(SR)<br>Repeated START condition<br>setup time|Repeated START condition<br>setup time|4.7||0.6|||
|tsu(SP)<br>STOP condition setup time|STOP condition setup time|4||0.6|||
|tw(SP:SR)<br>Bus free time between STOP<br>and START condition|Bus free time between STOP<br>and START condition|4.7||1.3|||



1. Data based on standard I[2] C protocol requirement, not tested in production 

**Figure 4. I²C slave timing diagram** 

_Note: Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both ports._ 

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**Table 9. I²C high-speed mode specifications at 1 MHz and 3.4 MHz** 

||**Symbol**|**Parameter**|**Min**|**Max**|**Unit**|
|---|---|---|---|---|---|
|Fast mode<br>plus(1)|fSCL|SCL clock frequency|0|1|MHz|
||tHD;STA|Hold time (repeated) START condition|260|-|ns|
||tLOW|Low period of the SCL clock|500|-||
||tHIGH|High period of the SCL clock|260|-||
||tSU;STA|Setup time for a repeated START condition|260|-||
||tHD;DAT|Data hold time|0|-||
||tSU;DAT|Data setup time|50|-||
||trDA|Rise time of SDA signal|-|120||
||tfDA|Fall time of SDA signal|-|120||
||trCL|Rise time of SCL signal|20*Vdd/5.5|120||
||tfCL|Fall time of SCL signal|20*Vdd/5.5|120||
||tSU;STO|Setup time for STOP condition|260|-||
||Cb|Capacitive load for each bus line|-|550|pF|
||tVD;DAT|Data valid time|-|450|ns|
||tVD;ACK|Data valid acknowledge time|-|450||
||VnL|Noise margin at low level|0.1Vdd|-|V|
||VnH|Noise margin at high level|0.2Vdd|-||
||tSP|Pulse width of spikes that must be suppressed<br>by the input filter|0|50|ns|
|High-speed<br>mode(1)|fSCLH|SCLH clock frequency|0|3.4|MHz|
||tSU;STA|Setup time for a repeated START condition|160|-|ns|
||tHD;STA|Hold time (repeated) START condition|160|-||
||tLOW|Low period of the SCLH clock|160|-||
||tHIGH|High period of the SCLH clock|60|-||
||tSU;DAT|Data setup time|10|-||
||tHD;DAT|Data hold time|0|70||
||trCL|Rise time of SCLH signal|10|40||
||trCL1|Rise time of SCLH signal after a repeated<br>START condition and after an acknowledge bit|10|80||
||tfCL|Fall time of SCLH signal|10|40||
||trDA|Rise time of SDAH signal|10|80||
||tfDA|Fall time of SDAH signal|10|80||
||tSU;STO|Setup time for STOP condition|160|-||
||Cb|Capacitive load for each bus line|-|100|pF|
||VnH|Noise margin at high level|0.2Vdd|-|V|
||tSP|Pulse width of spikes that must be suppressed<br>by the input filter|0|10|ns|



1. Data based on characterization, not tested in production 

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**AIS2DW12** 

**Mechanical and electrical specifications** 

## **2.5 Absolute maximum ratings** 

Stresses above those listed as “absolute maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. 

**Table 10. Absolute maximum ratings** 

|**Symbol**|**Ratings**|**Maximum value**|**Unit**|
|---|---|---|---|
|Vdd|Supply voltage|-0.3 to 4.8|V|
|Vdd_IO|I/O pins supply voltage|-0.3 to 4.8|V|
|Vin|Input voltage on any control pin<br>(CS, SCL/SPC, SDA/SDI/SDO, SDO/SA0)|-0.3 to Vdd_IO +0.3|V|
|AUNP|Acceleration (any axis, unpowered)|3000_g_for 0.5 ms|_g_|
|||10000_g_for 0.2 ms|_g_|
|TOP|Operating temperature range|-40 to +85|°C|
|TSTG|Storage temperature range|-40 to +125|°C|
|ESD|Electrostatic discharge protection|2 kV (HBM)<br>200 V (MM)<br>500 V (CDM)||



_Note: Supply voltage on any pin should never exceed 4.8 V._ 

This device is sensitive to mechanical shock, improper handling can cause permanent damage to the part. 

This device is sensitive to electrostatic discharge (ESD), improper handling can cause permanent damage to the part. 

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**Terminology and functionality** 

**AIS2DW12** 

## **3 Terminology and functionality** 

## **3.1 Terminology** 

## **3.1.1 Sensitivity** 

Sensitivity describes the gain of the sensor and can be determined 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 time. The sensitivity tolerance describes the range of sensitivities of a large population of sensors. 

## **3.1.2** 

## **Zero-** _**g**_ **level offset** 

Zero- _g_ level offset 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_ on the X-axis and 0 _g_ on the 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 two’s complement number). A deviation from ideal value in this case is called Zero- _g_ level offset. Offset is to some extent a result of stress to the 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 offset change vs. temperature”. 

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**Terminology and functionality** 

## **3.2 Functionality** 

## **3.2.1 Operating modes** 

The AIS2DW12 offers 2 operating modes: continuous mode and single-shot mode, selectable through OP_MODE[1:0] in _CTRL1 (20h)_ . Each operating mode supports four different power modes, selectable through PW_MODE[1:0] in _CTRL1 (20h)_ . 

**Table 11. Operating modes** 

|**Parameter**|**Parameter**|**Power Mode 4**|**Power Mode 3**|**Power Mode 2**|**Power Mode 1**|
|---|---|---|---|---|---|
|Resolution [bit]||14-bit|14-bit|14-bit|12-bit|
|ODR [Hz]||1.6 - 100|1.6 - 100|1.6 - 100|1.6 - 100|
|BW [Hz]||180<br>ODR/4, ODR/10,<br>ODR/20|360<br>ODR/4, ODR/10,<br>ODR/20|720<br>ODR/4, ODR/10,<br>ODR/20|3200<br>ODR/4, ODR/10,<br>ODR/20|
|Typ. RMS noise [m_g_(RMS)]||1.6|2.1|3.0|5.5|
|Typ. current<br>consumption<br>[μA]<br>@ Vdd=1.8 V(1)|ODR=1.6 Hz|0.65|0.55|0.45|0.38|
||ODR=12.5 Hz|4|2.5|1.6|1|
||ODR=25 Hz|8.5|4.5|3|1.5|
||ODR=50 Hz|16|9|5.5|3|
||ODR=100 Hz|32|17.5|10.5|5|
|Typ. current<br>consumption<br>[μA]<br>@ Vdd=3 V(1)|ODR=1.6 Hz|1.3|0.95|0.75|0.67|
||ODR=12.5 Hz|5.3|3|2|1.3|
||ODR=25 Hz|10.5|6|3.8|2.1|
||ODR=50 Hz|20.5|11.5|7|3.7|
||ODR=100 Hz|40|22|13.5|6.5|



1. Verified at characterization level. 

## **3.2.2 Single data conversion on-demand mode** 

The device features a single data conversion on-demand mode in the 4 power modes. This mode is enabled by writing the OP_MODE[1:0] bits to '10' in _CTRL1 (20h)_ . Power modes are selected by writing the PW_MODE[1:0] bits in _CTRL1 (20h)_ . 

The trigger for output data generation can be managed through the I[2] C/SPI or by applying a clock signal on the INT2 pin acting here as an input by writing the SLP_MODE_ SEL bit in _CTRL3 (22h)_ : 

- When SLP_MODE_SEL = '0', output data generation is triggered by the clock signal on the INT2 pin (see _Figure 5_ ). 

- When SLP_MODE_SEL = '1', output data generation starts when the SLP_MODE_1 bit is set to '1' logic through the I[2] C/SPI. When XL data are available in the registers, this bit is automatically set to '0' and the device is ready for another triggered session. 

Output data are generated according to the selected power mode. 

When output data is saved in an output register or FIFO, the device goes to power-down mode and waits for a new trigger. 

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**Terminology and functionality** 

**AIS2DW12** 

All ODRs in the range from 0 to up to 100 Hz are supported due to the INT2 clock input. A DRDY signal or FIFO flags are available on the INT1 pin. 

Power consumption is the same as that of standard power modes for the same ODR. 

**Figure 5. Single data conversion on demand functionality** 

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At the end of turn-on time T_on, the DRDY interrupt is activated, output data are available to be read and the device goes into power-down. T_on values depend on the power mode as follows: 

T_on (typ.) = 

- 1.20 ms for Power Mode 1 

- 1.70 ms for Power Mode 2 

- 2.30 ms for Power Mode 3 

- 3.55 ms for Power Mode 4 

## **3.2.3** 

## **Self-test** 

The self-test allows checking the sensor functionality without moving it. The self-test function is off when the self-test bits (ST) are programmed to ‘00’. When the self-test bits are changed, 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 the self-test is activated, the device output level is given by the algebraic sum of the signals produced by the acceleration acting on the sensor and by the electrostatic test-force. If the output signals change within the amplitude specified in _Table 4_ , then the sensor is working properly and the parameters of the interface chip are within the defined specifications. 

## **3.2.4** 

## **Activity/Inactivity, stationary/motion detection functions** 

The activity/inactivity function recognizes the device’s sleep state and allows reducing system power consumption. 

When the activity/inactivity function is activated by setting the SLEEP_ON bit in _WAKE_UP_THS (34h)_ , the AIS2DW12 automatically goes to 12.5 Hz ODR in the mode previously selected by the PW_MODE[1:0] bits in _CTRL1 (20h)_ if the sleep state condition is detected and wakes up as soon as the interrupt event has been detected, increasing the output data rate and bandwidth. 

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**Terminology and functionality** 

With this feature the system may be efficiently switched from 12.5 Hz to full performance depending on user-selectable positioning and acceleration events, thus ensuring power saving and flexibility. 

The stationary/motion detection function only recognizes the device’s sleep state. 

When the stationary/motion detection function is activated by setting the STATIONARY bit in _WAKE_UP_DUR (35h)_ , the AIS2DW12 detects acceleration below a fixed threshold but does not change either ODR or operating mode after sleep state detection. 

The Activity/Inactivity recognition and stationary/motion detection functions are activated by writing the desired threshold in the _WAKE_UP_THS (34h)_ register. The high-pass filter is automatically enabled. 

If the device is in sleep (inactivity/stationary) mode, when at least one of the axes exceeds the threshold in _WAKE_UP_THS (34h)_ , the device goes into a sleep-to-wake state (as wake-up). 

For the activity/inactivity function, the device, in a wake-up state, will return to the operating mode and ODR before sleep state detection. 

Activity/Inactivity, stationary/motion detection threshold and duration can be configured in the following control registers: 

_WAKE_UP_THS (34h)_ 

_WAKE_UP_DUR (35h)_ 

## **3.2.5** 

## **Offset management** 

The user can manage offset in the output or for wakeup detection using dedicated embedded hardware (see _Section 5.1: Block diagram of filters_ ). 

## **3.3 Sensing element** 

A proprietary process is used to create a surface micromachined accelerometer. The technology allows processing 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. In order 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 molding 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 halfbridge. 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 a few pF and when an acceleration is applied, the maximum variation of the capacitive load is in the fF range. 

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**Terminology and functionality** 

**AIS2DW12** 

## **3.4 IC interface** 

The complete measurement chain is composed of a low-noise capacitive amplifier which converts the capacitive unbalancing of the MEMS sensor into an analog voltage using an analog-to-digital converter. 

The acceleration data may be accessed through an I[2] C/SPI interface thus making the device particularly suitable for direct interfacing with a microcontroller. 

The AIS2DW12 features a data-ready signal which indicates when a new set of measured acceleration data is available, thus simplifying data synchronization in the digital system that uses the device. 

## **3.5 Factory calibration** 

The IC interface is factory-calibrated for sensitivity (So) and Zero- _g_ level offset. 

The trim values are stored inside the device in nonvolatile memory. Any time the device is turned on, the trimming parameters are downloaded into the registers to be used during active operation. This allows using the device without further calibration. If an accidental write occurs in the registers where trimming parameters are stored, the BOOT bit in _CTRL2 (21h)_ can help to retrieve the correct trimming parameters from nonvolatile memory without the need to switch on/off the device. This bit is automatically reset at the end of the download operation. Setting this bit has no impact on the control registers. 

## **3.6 Temperature sensor** 

The temperature is available in _OUT_T_L (0Dh)_ , _OUT_T_H (0Eh)_ stored as two's complement data, left-justified in 12-bit mode and in _OUT_T (26h)_ stored as two's complement data, left-justified in 8-bit mode. 

Refer to _Table 6: Temperature sensor characteristics_ for the conversion factor. 

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**AIS2DW12** 

**Application hints** 

## **4 Application hints** 

**Figure 6. AIS2DW12 electrical connections (top view)** 

The device core is supplied through the Vdd line while the I/O pads are supplied through the Vdd_IO line. Power supply decoupling capacitors (100 nF ceramic, 10 μF aluminum) should be placed as near as possible to pin 9 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 6_ ). It is possible to remove Vdd while 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 are selectable and accessible through the I[2] C or SPI interfaces. When using the I[2] C, CS must be tied high (i.e. connected to Vdd_IO). 

The functions, the threshold and the timing of the two interrupt pins (INT1 and INT2) can be completely programmed by the user through the I[2] C/SPI interface. 

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**Application hints** 

**Table 12. Internal pin status** 

|**Pin #**|**Name**|**Function**|**Pin status**|
|---|---|---|---|
|1|SCL<br>SPC|I2C serial clock (SCL)<br>SPI serial port clock (SPC)|Default: open drain|
|2|CS|SPI enable<br>I2C/SPI mode selection<br>1: SPI idle mode / I2C communication enabled<br>0: SPI communication mode / I2C disabled|Default: input with internal pull-up(1)|
|3|SDO<br>SA0|Serial data output (SDO)<br>I2C less significant bit of the device address (SA0)|Default: input with internal pull-up|
|4|SDA<br>SDI<br>SDO|I2C serial data (SDA)<br>SPI serial data input (SDI)<br>3-wire interface serial data output (SDO)|Default: (SDA) input open drain|
|5|NC|Internally not connected. Can be tied to VDD,<br>VDDIO, or GND.||
|6|GND|0 V supply||
|7|RES|Connect to GND||
|8|GND|0 V supply||
|9|VDD|Power supply||
|10|VDD_IO|Power supply for I/O pins||
|11|INT2|Interrupt pin 2. Clock input when selected in single<br>data conversion on demand.|Default: push-pull output forced to Gnd|
|12|INT1|Interrupt pin 1|Default: push-pull output forced to Gnd|



1. Pull-up on the CS pin can be removed by performing an I[2] C/SPI write procedure 

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**AIS2DW12** 

**Digital main blocks** 

## **5 Digital main blocks** 

## **5.1 Block diagram of filters** 

**Figure 7. Accelerometer chain** 

Referring to _Figure 7_ , the first block is the Low-Pass Filter 1 (LPF1) whose behavior is a function of the actual ODR and mode selected in _CTRL1 (20h)_ . The signal is then downsampled and can be either directly sent to the output registers or to the Low-Pass Filter 2 (LPF2) or High-Pass-Filter (HP) using the BW_FILT[1:0] bits and FDS bit in _CTRL6 (25h)_ . 

In the low-pass path, it is possible to apply a user offset determined by the _X_OFS_USR (3Ch)_ , _Y_OFS_USR (3Dh)_ , _Z_OFS_USR (3Eh)_ register values and the USR_OFF_W bit in _CTRL7 (3Fh)_ and send the result to the output using the USR_OFF_ON_OUT bit in _CTRL7 (3Fh)_ . 

In the high-pass path, it is possible to use the high-pass filter reference mode (HP) using the HP_REF_MODE bit in _CTRL7 (3Fh)_ . 

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**Digital main blocks** 

## **5.2 FIFO** 

The AIS2DW12 embeds 32 slots of 14-bit data FIFO for each of the three output channels, X, Y and Z of the acceleration data. This allows consistent power saving for the system, since the host processor does not need to continuously poll data from the sensor, but it can wake up only when needed and burst the significant data out from the FIFO. 

The internal FIFO allows collecting 32 samples (14-bit size data) for each axis. 

When the FIFO mode is other than Bypass, reading the output registers (28h to 2Dh) returns the oldest FIFO sample set. In order to minimize communication between the master and slave, the address read may be automatically incremented by the device by setting the IF_ADD_INC bit of _CTRL2 (21h)_ to '1'; the device rolls back to 0x28 when register 0x2D is reached. 

This buffer can work according to the following 5 different modes: 

- Bypass mode 

- FIFO mode 

- Continuous-to-FIFO 

- Bypass-to-Continuous 

- Continuous 

Each mode is selected by the FMode[2:0] bits in the _FIFO_CTRL (2Eh)_ register. 

Programmable FIFO threshold is selected in _FIFO_CTRL (2Eh)_ . Status and FIFO overrun events are available in the _FIFO_SAMPLES (2Fh)_ register and can be used to generate dedicated interrupts on the INT1 and INT2 pins using the _CTRL4_INT1 (23h)_ and _CTRL5_INT2 (24h)_ registers. 

_FIFO_SAMPLES (2Fh)_ (FIFO_FTH) goes to '1' when the number of unread samples _FIFO_SAMPLES (2Fh)_ (Diff[5:0]) is greater than or equal to FTH[4:0] in _FIFO_CTRL (2Eh)_ . 

If FTH[4:0] is equal to '0', _FIFO_SAMPLES (2Fh)_ (FIFO_FTH) goes to '0'. 

_FIFO_SAMPLES (2Fh)_ (FIFO_OVR) is equal to '1' if a FIFO slot is overwritten. 

_FIFO_SAMPLES (2Fh)_ (Diff[5:0]) contains stored data levels of unread samples. When Diff[5:0] is equal to ‘000000’, FIFO is empty. When Diff[5:0] is equal to ‘100000’, FIFO is full and the unread samples are 32. 

To guarantee the correct acquisition of data during the switching into and out of FIFO, the first sample acquired must be discarded. 

When the FIFO threshold status flag is '0'-logic, FIFO filling is lower than the threshold level and when '1'-logic, FIFO filling is equal to or higher than the threshold level. 

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**Digital main blocks** 

## **5.2.1 Bypass mode** 

In Bypass mode ( _FIFO_CTRL (2Eh)_ (FMode [2:0])= 000), the FIFO is not operational, no data is collected in FIFO memory, and it remains empty with the only actual sample available in the output registers. 

Bypass mode is also used to reset the FIFO when in FIFO mode. 

For each channel only the first address is used. When new data is available, the old data is overwritten. 

## **5.2.2 FIFO mode** 

In FIFO mode ( _FIFO_CTRL (2Eh)_ (FMode [2:0])= 001) data from the X, Y and Z channels are stored in the FIFO until it is full, when 32 unread samples are stored in memory, data collecting is stopped. 

To reset the FIFO content, Bypass mode should be written in the _FIFO_CTRL (2Eh)_ register, setting the FMODE [2:0] bits to '000'. After this reset command, it is possible to restart FIFO mode, writing the value '001' in _FIFO_CTRL (2Eh)_ (FMODE [2:0]). 

The FIFO buffer can memorize 32 slots of X, Y and Z data. 

## **5.2.3 Continuous mode** 

Continuous mode ( _FIFO_CTRL (2Eh)_ (FMode[2:0] = 110) provides a continuous FIFO update: when 32 unread samples are stored in memory, as new data arrives the oldest data is discarded and overwritten by the newer. 

A FIFO threshold flag _FIFO_SAMPLES (2Fh)_ (FIFO_FTH) is asserted when the number of unread samples in FIFO is greater than or equal to ( _FIFO_CTRL (2Eh)_ FTH[4:0]). 

It is possible to route _FIFO_SAMPLES (2Fh)_ (FTH) to the INT1 pin by writing the INT1_FTH bit to '1' in register _CTRL4_INT1 (23h)_ or to the INT2 pin by writing the INT2_FTH bit to '1' in register _CTRL5_INT2 (24h)_ . 

If an overrun occurs, the oldest sample in FIFO is overwritten and the FIFO_OVR flag in _FIFO_SAMPLES (2Fh)_ is asserted. 

In order to empty the FIFO before it is full, it is also possible to pull from FIFO the number of unread samples available in _FIFO_SAMPLES (2Fh)_ (Diff[5:0]). 

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**Digital main blocks** 

## **5.2.4 Continuous-to-FIFO mode** 

In Continuous-to-FIFO mode _FIFO_CTRL (2Eh)_ (FMode[2:0] = 011), FIFO operates in Continuous mode and FIFO mode starts upon an internal trigger event. When the FIFO is full, data collecting is stopped. The trigger could be wake-up, free-fall, 6D interrupt or any combination of these events, but every interrupt has to be routed on the corresponding pad to be used as a trigger. 

**Figure 8. Continuous-to-FIFO mode** 

**==> picture [334 x 191] intentionally omitted <==**

**----- Start of picture text -----**<br>
— xi,yi,z - i {__[ x0 y0 z0 xi,yi,zi x0 y0 z0<br>x1 y1 z1<br>[J | | —+=f-7~ x1 y1 [| z1<br>ft rT.<br>x2 y2 z2<br>x2 y2 z2<br>x30 y30 z30<br>x31 y31 z31<br>x31 y31 z31<br>Continuous Mode FIFO Mode<br>(~<br>Trigger event<br>**----- End of picture text -----**<br>


**Figure 9. Trigger event to FIFO for Continuous-to-FIFO mode** 

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**AIS2DW12** 

**Digital main blocks** 

## **5.2.5 Bypass-to-Continuous mode** 

In Bypass-to-Continuous mode ( _FIFO_CTRL (2Eh)_ (FMode[2:0] = '100'), data measurement storage inside FIFO starts in Continuous mode upon an internal trigger event, then the sample that follows the trigger is available in FIFO. The trigger could be wake-up, free-fall, 6D interrupt or any combination of these events, but every interrupt has to be routed on the corresponding pad to be used as a trigger. 

**Figure 10. Bypass-to-Continuous mode** 

**==> picture [346 x 163] intentionally omitted <==**

**----- Start of picture text -----**<br>
—r xi,yi,z i i _ x0 | y0 | z0 | — xi,yi,z > i x0 y0 z0<br>x1 y1 z1<br>x1 y1 z1<br>x2 y2 z2<br>empty x2 y2 z2<br>x30 y30 z30<br>x31 y31 z31<br>| x31 y31 z31<br>Bypass Mode Continuous Mode<br>ee e e<br>Trigger event<br>**----- End of picture text -----**<br>


**Figure 11. Trigger event to FIFO for Bypass-to-Continuous mode** 

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**AIS2DW12** 

## **6 Digital interfaces** 

The registers embedded inside the AIS2DW12 may be accessed through both the I[2] C 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 to the same pins. To select/exploit the I[2] C interface, the CS line must be tied high (i.e. connected to Vdd_IO). 

**Table 13. Serial interface pin description** 

||**Table 13. Serial interface pin description**|
|---|---|
|**Pin name**|**Pin description**|
|CS|SPI enable<br>I2C/SPI mode selection (1: SPI idle mode / I2C communication enabled; 0: SPI<br>communication mode / I2C disabled)|
|SCL<br>SPC|I2C serial clock (SCL)<br>SPI serial port clock (SPC)|
|SDA<br>SDI<br>SDO|I2C serial data (SDA)<br>SPI serial data input (SDI)<br>3-wire interface serial data output (SDO)|
|SA0<br>SDO|I2C address selection (SA0)<br>SPI serial data output (SDO)|



## **6.1 I²C serial interface** 

The AIS2DW12 I[2] C is a bus slave. The I[2] C is employed to write data into registers whose content can also be read back. 

The relevant I[2] C terminology is given in the table below. 

**Table 14. I²C terminology** 

||**Table 14. I²C terminology**|
|---|---|
|**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<br>transfer|
|Slave|The device addressed by the master|



There are two signals associated with the I[2] C 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 must be connected to Vdd_IO through an external pullup resistor. When the bus is free, both the lines are high. 

The I[2] C interface is compliant with fast mode (400 kHz) I[2] C standards as well as with normal mode. 

In order to disable the I[2] C block, _CTRL2 (21h)_ (I2C_DISABLE) = 1 must be set. 

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**Digital interfaces** 

## **6.1.1 I[2] C 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 AIS2DW12 is 001100xb where the x bit is modified by the SA0/SDO pin in order to modify the device address. If the SA0/SDO pin is connected to the supply voltage, the address is 0011001b, otherwise if the SA0/SDO pin is connected to ground, the address is 0011000b. This solution permits to connect and address two different accelerometers to the same I[2] C 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 I[2] C embedded inside the AIS2DW12 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, an 8-bit sub-address (SUB) is transmitted: the 7 LSb represents the actual register address while the _CTRL2 (21h)_ (IF_ADD_INC) bit defines the address increment. 

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 transmit to the slave with direction unchanged. _Table 15_ explains how the SAD+Read/Write bit pattern is composed, listing all the possible configurations. 

|**Table 15. SAD+Read/Write patterns**|**Table 15. SAD+Read/Write patterns**|**Table 15. SAD+Read/Write patterns**|**Table 15. SAD+Read/Write patterns**|**Table 15. SAD+Read/Write patterns**|
|---|---|---|---|---|
|**Command**|**SAD[6:1]**|**SAD[0] = SA0**|**R/W**|**SAD+R/W**|
|Read|001100|0|1|00110001 (31h)|
|Write|001100|0|0|00110000 (30h)|
|Read|001100|1|1|00110011 (33h)|
|Write|001100|1|0|00110010 (32h)|



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**Table 16. Transfer when master is writing one byte to slave** 

|Master|ST|SAD + W||SUB||DATA||SP|
|---|---|---|---|---|---|---|---|---|
|Slave|||SAK||SAK||SAK||



**Table 17. Transfer when master is writing multiple bytes to slave** 

|Master|ST|SAD + W||SUB||DATA||DATA||SP|
|---|---|---|---|---|---|---|---|---|---|---|
|Slave|||SAK||SAK||SAK||SAK||



**Table 18. 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 19. 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|||



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 the presented communication format MAK is Master acknowledge and NMAK is No Master Acknowledge. 

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## **6.2 SPI bus interface** 

The AIS2DW12 SPI is a bus slave. The SPI allows writing to and reading from the registers of the device. 

The serial interface interacts with the application using 4 wires: **CS** , **SPC** , **SDI** and **SDO** . 

**Figure 12. Read and write protocol** 

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**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 multiples of 8 in case of multiple read/write bytes. 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 1-7**_ : address AD(6:0). 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 additional blocks of 8 clock periods will be added. When the _CTRL2 (21h)_ (IF_ADD_INC) bit is ‘0’, the address used to read/write data remains the same for every block. When the _CTRL2 (21h)_ (IF_ADD_INC) bit is ‘1’, the address used to read/write data is increased at every block. 

The function and the behavior of **SDI** and **SDO** remain unchanged. 

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## **6.2.1 SPI read** 

**Figure 13. SPI read protocol** 

The SPI read command is performed with 16 clock pulses. A multiple byte read command is performed by adding blocks of 8 clock pulses to the previous one. 

_**bit 0**_ : READ bit. The value is 1. 

_**bit 1-7**_ : address AD(6:0). 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). Additional data in multiple byte reads. 

**Figure 14. Multiple byte SPI read protocol (2-byte example)** 

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## **6.2.2 SPI write** 

**Figure 15. SPI write protocol** 

The SPI write command is performed with 16 clock pulses. A multiple byte write command is performed by adding blocks of 8 clock pulses to the previous one. 

_**bit 0**_ : WRITE bit. The value is 0. 

_**bit 1 -7**_ : address AD(6:0). 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). Additional data in multiple byte writes. 

**Figure 16. Multiple byte SPI write protocol (2-byte example)** 

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## **6.2.3 SPI read in 3-wire mode** 

3-wire mode is entered by setting the _CTRL2 (21h)_ (SIM) bit equal to ‘1’ (SPI serial interface mode selection). 

**Figure 17. SPI read protocol in 3-wire mode** 

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The SPI read command is performed with 16 clock pulses: 

_**bit 0**_ : READ bit. The value is 1. 

_**bit 1-7**_ : address AD(6:0). 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). 

A multiple read command is also available in 3-wire mode. 

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**Register mapping** 

## **7 Register mapping** 

The table given below provides a list of the 8-bit registers embedded in the device and the corresponding addresses. 

**Table 20. Register map** 

|**Name**|**Type(1)**|**Register address**|**Register address**|**Default**|**Comment**|
|---|---|---|---|---|---|
|||**Hex**|**Binary**|||
|OUT_T_L|R|0D|00001101|00000000|Temp sensor output|
|OUT_T_H|R|0E|00001110|00000000||
|WHO_AM_I|R|0F|00001111|01000100|Who am I ID|
|RESERVED|-|10-1F||-|RESERVED|
|CTRL1|R/W|20|00100000|00000000|Control registers|
|CTRL2|R/W|21|00100001|00000100||
|CTRL3|R/W|22|00100010|00000000||
|CTRL4_INT1|R/W|23|00100011|00000000||
|CTRL5_INT2|R/W|24|00100100|00000000||
|CTRL6|R/W|25|00100101|00000000||
|OUT_T|R|26|00100110|00000000|Temp sensor output|
|STATUS|R|27|00100111|00000000|Status data register|
|OUT_X_L|R|28|00101000|00000000|Output registers|
|OUT_X_H|R|29|00101001|00000000||
|OUT_Y_L|R|2A|00101010|00000000||
|OUT_Y_H|R|2B|00101011|00000000||
|OUT_Z_L|R|2C|00101100|00000000||
|OUT_Z_H|R|2D|00101101|00000000||
|FIFO_CTRL|R/W|2E|00101110|00000000|FIFO control register|
|FIFO_SAMPLES|R|2F|00101111|00000000|Unread samples<br>stored in FIFO|
|SIXD_THS|R/W|30|00110000|00000000|6D threshold|
|RESERVED|-|31-33||-|RESERVED|
|WAKE_UP_THS|R/W|34|00110100|00000000|Inactivity enable,<br>wakeup threshold|
|WAKE_UP_DUR|R/W|35|00110101|00000000|Wakeup duration|
|FREE_FALL|R/W|36|00110110|00000000|Free-fall configuration|
|STATUS_DUP|R|37|00110111|00000000|Status register|
|WAKE_UP_SRC|R|38|00111000|00000000|Wakeup source|
|RESERVED|-|39|00111001|-|RESERVED|



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**Table 20. Register map (continued)** 

|**Name**|**Type(1)**|**Register address**|**Register address**|**Default**|**Comment**|
|---|---|---|---|---|---|
|||**Hex**|**Binary**|||
|SIXD_SRC|R|3A|00111010|00000000|6D source|
|ALL_INT_SRC|R|3B|00111011|00000000||
|X_OFS_USR|R/W|3C|00111100|00000000||
|Y_OFS_USR|R/W|3D|00111110|00000000||
|Z_OFS_USR|R/W|3E|00000100|00000000||
|CTRL_REG7|R/W|3F|00000100|00000000||



1. R = read-only register, R/W = readable/writable register 

Registers marked as _Reserved_ must not be changed. Writing to those registers may cause permanent damage 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. 

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## **8 Register description** 

## **8.1 OUT_T_L (0Dh)** 

Temperature output register in 12-bit resolution (r). 

## **Table 21. OUT_T_L register** 

TEMP3 TEMP2 TEMP1 TEMP0 0 0 0 0 

## **Table 22. OUT_T_L register description** 

|TEMP[3:0]|The 8 least significant bits of the temperature sensor output. Sensitivity = 16 LSB/°C.<br>Together with_OUT_T_H (0Eh)_, it forms the output value expressed as a 16-bit word<br>in 2's complement.|
|---|---|



## **8.2 OUT_T_H (0Eh)** 

Temperature output register in 12-bit resolution (r). 

## **Table 23. OUT_T_H register** 

TEMP11 TEMP10 TEMP9 TEMP8 TEMP7 TEMP6 TEMP5 TEMP4 

## **Table 24. OUT_T_H register description** 

|TEMP[11:4]|The 8 most significant bits of the temperature sensor output. Sensitivity = 16 LSB/°C.<br>Together with_OUT_T_L (0Dh)_, it forms the output value expressed as a 16-bit word<br>in 2's complement|
|---|---|



## **8.3 WHO_AM_I (0Fh)** 

Who_AM_I register (r). This register is a read-only register. Its value is fixed at 44h. 

**Table 25. WHO_AM_I register default values** 

0 1 0 0 0 1 0 0 

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**Register description** 

## **8.4 CTRL1 (20h)** 

Control register 1 (r/w) 

**Table 26. Control register 1** 

|ODR3|ODR2|ODR1|ODR0|OP_<br>MODE1|OP_<br>MODE0|PW_<br>MODE1|PW_<br>MODE0|
|---|---|---|---|---|---|---|---|



## **Table 27. Control register 1 description** 

||**Table 27. Control register 1 description**|
|---|---|
|ODR[3:0]|Output data rate and mode selection (see_Table 28_)|
|OP_MODE[1:0]|Operating mode selection (see_Table 29_)|
|PW_MODE[1:0]|Power mode selection (see_Table 30_)|



ODR[3:0] is used to set the power mode and ODR selection. The following table lists the bit settings for power-down mode and each available frequency. 

**Table 28. Data rate configuration** 

|**ODR[3:0]**<br>0000<br>0001<br>0010<br>0011<br>0100<br>0101|**Power mode / data rate configuration**|
|---|---|
||Power-down|
||1.6 Hz|
||12.5 Hz|
||25 Hz|
||50 Hz|
||100 Hz|



**Table 29. Operating mode selection** 

|**OP_MODE[1:0]**|**Mode and resolution**|
|---|---|
|00|Continuous Mode (12/14-bit resolution)|
|01|-|
|10|Single data conversion on-demand mode (12/14-bit resolution)|
|11|-|



**Table 30. Power mode selection** 

|**PW_MODE[1:0]**|**Power mode and resolution**|
|---|---|
|00|Power Mode 1 (12-bit resolution)|
|01|Power Mode 2 (14-bit resolution)|
|10|Power Mode 3 (14-bit resolution)|
|11|Power Mode 4 (14-bit resolution)|



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**Register description** 

## **8.5 CTRL2 (21h)** 

Control register 2 (r/w) 

**Table 31. Control register 2** 

|BOOT|SOFT_<br>RESET|0(1)|CS_PU_<br>DISC|BDU|IF_ADD_<br>INC|I2C_<br>DISABLE|SIM|
|---|---|---|---|---|---|---|---|



1. This bit must be set to ‘0’ for the correct operation of the device. 

**Table 32. Control register 2 description** 

||**Table 32. Control register 2 description**|
|---|---|
|BOOT|Boot enables retrieving the correct trimming parameters from nonvolatile memory<br>into registers where trimming parameters are stored.<br>Once the operation is over, this bit automatically returns to 0.<br>Default value: 0 (0: disabled; 1: enabled)|
|SOFT_RESET|Soft reset acts as reset for all control registers, then goes to 0.<br>Default value: 0 (0: disabled; 1: enabled)|
|CS_PU_DISC|Disconnect CS pull-up. Default value: 0<br>(0: pull-up connected to CS pin;<br>1: pull-up disconnected to CS pin)|
|BDU|Block data update. Default value: 0<br>(0: continuous update; 1: output registers not updated until MSB and LSB read)|
|IF_ADD_INC|Register address automatically incremented during multiple byte access with a<br>serial interface (I2C or SPI). Default value: 1 (0: disabled; 1: enabled)|
|I2C_DISABLE|Disable I2C communication protocol. Default value: 0<br>(0: SPI and I2C interfaces enabled; 1: I2C mode disabled)|
|SIM|SPI serial interface mode selection. Default value: 0<br>0: 4-wire interface; 1: 3-wire interface|



The BDU bit is used to inhibit the update of the output registers until both upper and lower register parts are read. In default mode (BDU = ‘0’) the output register values are updated continuously. When the BDU is activated (BDU = ‘1’), the content of the output registers is not updated until both MSB and LSB are read which avoids reading values related to different sample times. 

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## **8.6 CTRL3 (22h)** 

Control register 3 (r/w) 

## **Table 33. Control register 3** 

|ST2|ST1|PP_OD|LIR|H_LACTIVE|0|SLP_<br>MODE_SEL|SLP_<br>MODE_1|
|---|---|---|---|---|---|---|---|



**Table 34. Control register 3 description** 

||**Table 34. Control register 3 description**|
|---|---|
|ST[2:1]|Self-test enable. Default value: 00<br>(00: Self-test disabled; Other: see_Table 35_)|
|PP_OD|Push-pull/open-drain selection on interrupt pad. Default value: 0<br>(0: push-pull; 1: open-drain)|
|LIR|Latched Interrupt. Switches between latched ('1'-logic) and pulsed ('0'-logic) mode for<br>function source signals and interrupts routed to pins. Default value: 0<br>(0: interrupt request not latched; 1: interrupt request latched)|
|H_LACTIVE|Interrupt active high, low. Default value: 0<br>(0: active high; 1: active low)|
|SLP_<br>MODE_SEL|Single data conversion on demand mode selection:<br>0: enabled with external trigger on INT2;<br>1: enabled by I2C/SPI writing SLP_MODE_1 to 1.|
|SLP_<br>MODE_1|Single data conversion on demand mode enable. When SLP_MODE_SEL = '1' and<br>this bit is set to '1' logic, single data conversion on demand mode starts. When XL<br>data are available in the registers, this bit is set to '0' automatically and the device is<br>ready for another triggered session.|



## **Table 35. Self-test mode selection** 

|**ST2**|**ST1**|**Self-test mode**|
|---|---|---|
|0|0|Normal mode|
|0|1|Positive sign self-test|
|1|0|Negative sign self-test|
|1|1|-|



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**Register description** 

## **8.7 CTRL4_INT1 (23h)** 

Control register 4 (r/w) 

**Table 36. Control register 4** 

|INT1_6D|0|INT1_WU|INT1_FF|0|INT1_<br>DIFF5|INT1_<br>FTH|INT1_<br>DRDY|
|---|---|---|---|---|---|---|---|



**Table 37. Control register 4 description** 

||**Table 37. Control register 4 description**|
|---|---|
|INT1_6D|6D recognition is routed to INT1 pad. Default: 0<br>(0: disabled; 1: enabled)|
|INT1_WU|Wakeup recognition is routed to INT1 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT1_FF|Free-fall recognition is routed to INT1 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT1_DIFF5|FIFO full recognition is routed to INT1 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT1_FTH|FIFO threshold interrupt is routed to INT1 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT1_DRDY|Data-Ready is routed to INT1 pad. Default value: 0<br>(0: disabled; 1: enabled)|



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## **8.8 CTRL5_INT2 (24h)** 

Control register 5 (r/w) 

## **Table 38. Control register 5** 

|INT2_<br>SLEEP_<br>STATE|INT2_<br>SLEEP_<br>CHG|INT2_<br>BOOT|INT2_<br>DRDY_T|INT2_<br>OVR|INT2_<br>DIFF5|INT2_<br>FTH|INT2_<br>DRDY|
|---|---|---|---|---|---|---|---|



|**Table 39. Control register 5 description**|**Table 39. Control register 5 description**|
|---|---|
|INT2_SLEEP_STATE|Enable routing of SLEEP_STATE on INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2_SLEEP_CHG|Sleep change status routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2 _BOOT|Boot state routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2_DRDY_T|Temperature data-ready is routed to INT2. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2 _OVR|FIFO overrun interrupt is routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2_DIFF5|FIFO full recognition is routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2 _FTH|FIFO threshold interrupt is routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|
|INT2 _DRDY|Data-ready is routed to INT2 pad. Default value: 0<br>(0: disabled; 1: enabled)|



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## **8.9 CTRL6 (25h)** 

Control register 6 (r/w) 

**Table 40. Control register 6** 

BW_FILT1 BW_FILT0 FS1 FS0 FDS 0 0 0 

## **Table 41. Control register 6 description** 

|BW_FILT[1:0]|Bandwidth selection (see_Table 42_)|
|---|---|
|FS[1:0]|Full-scale selection (see_Table 45_)|
|FDS|Filtered data type selection. Default value: 0<br>(0: low-pass filter path selected;<br>1: high-pass filter path selected)|



**Table 42. Digital filtering cutoff selection (FDS bit set to ‘0’)** 

|**BW_FILT[1:0]**|**Bandwidth selection**|
|---|---|
|00|LPF1 only<br>refer to_Table 43: LPF1 cutoff (FDS bit set to '0')_|
|01|ODR/4|
|10|ODR/10|
|11|ODR/20|



**Table 43. LPF1 cutoff (FDS bit set to '0')** 

|**Mode**|**ODR selection**|**Cutoff [Hz]**|
|---|---|---|
|Low-Power Mode 4|@ each ODR|180|
|Low-Power Mode 3|@ each ODR|360|
|Low-Power Mode 2|@ each ODR|720|
|Low-Power Mode 1|@ each ODR|3200|



**Table 44.  Digital high-pass filter cutoff selection (FDS bit set to ‘1’)** 

|**BW_FILT[1:0]**|**Bandwidth selection**|
|---|---|
|00|ODR/4|
|01|ODR/4|
|10|ODR/10|
|11|ODR/20|



## **Table 45. Full-scale selection** 

||**Table 45. Full-scale selection**|
|---|---|
|**FS[1:0]**|**Full-scale selection**|
|00|±2_g_|
|01|±4_g_|



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## **8.10 OUT_T (26h)** 

Temperature output register in 8-bit resolution (r) 

## **Table 46. OUT_T register** 

|TEMP7|TEMP6|TEMP6|TEMP5|TEMP4|TEMP3|TEMP2|TEMP1|TEMP0|
|---|---|---|---|---|---|---|---|---|
|**Table 47. OUT_T register description**|||||||||
|TEMP[7:0]||Temperature sensor output data.<br>The value is expressed as two’s complement sign. Sensitivity = 1°C/LSB<br>0 LSB represents T=25 °C ambient.|||||||



## **8.11 STATUS (27h)** 

Status register (r). 

## **Table 48. STATUS register** 

|FIFO_THS|WU_IA|WU_IA|SLEEP_<br>STATE|0|0|6D_IA|FF_IA|DRDY|
|---|---|---|---|---|---|---|---|---|
|**Table 49. STATUS register description**|||||||||
|FIFO_THS||FIFO threshold status flag.<br>(0: FIFO filling is lower than threshold level;<br>1: FIFO filling is equal to or higher than the threshold level.)|||||||
|WU_IA||Wakeup event detection status.<br>(0: Wakeup event not detected; 1: Wakeup event detected)|||||||
|SLEEP_<br>STATE||Sleep event status.<br>(0: Sleep event not detected; 1: Sleep event detected)|||||||
|6D_IA||Source of change in position portrait/landscape/face-up/face-down.<br>(0: no event detected; 1: a change in position detected)|||||||
|FF_IA||Free-fall event detection status.<br>(0: free-fall event not detected; 1: free-fall event detected)|||||||
|DRDY||Data-ready status.<br>(0: not ready; 1: X-, Y- and Z-axis new data available)|||||||



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**Register description** 

## **8.12 OUT_X_L (28h)** 

X-axis LSB output register (r). 

## **Table 50. OUT_X_L register** 

X_L7 X_L6 X_L5 X_L4 X_L3[(1)] X_L2[(1)] 0 0 

1. If Power Mode 1 is enabled, this bit is set to 0. 

The 8 least significant bits of linear acceleration sensor X-axis output. Together with the _OUT_X_H (29h)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

## **8.13 OUT_X_H (29h)** 

X-axis MSB output register (r). 

## **Table 51. OUT_X_H register** 

X_H7 X_H6 X_H5 X_H4 X_H3 X_H2 X_H1 X_H0 

The 8 most significant bits of linear acceleration sensor X-axis output. Together with the _OUT_X_L (28h)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

## **8.14 OUT_Y_L (2Ah)** 

Y-axis LSB output register (r). 

## **Table 52. OUT_Y_L register** 

Y_L7 Y_L6 Y_L5 Y_L4 Y_L3[(1)] Y_L2[(1)] 0 0 

1. If Power Mode 1 is enabled, this bit is set to 0. 

The 8 least significant bits of linear acceleration sensor Y-axis output. Together with the _OUT_Y_H (2Bh)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

## **8.15 OUT_Y_H (2Bh)** 

Y-axis MSB output register (r). 

**Table 53. OUT_Y_H register** 

Y_H7 Y_H6 Y_H5 Y_H4 Y_H3 Y_H2 Y_H1 Y_H0 

The 8 most significant bits of linear acceleration sensor Y-axis output. Together with the _OUT_Y_L (2Ah)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

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## **8.16 OUT_Z_L (2Ch)** 

Z-axis LSB output register (r). 

## **Table 54. OUT_Z_L register** 

Z_L7 Z_L6 Z_L5 Z_L4 Z_L3[(1)] Z_L2[(1)] 0 0 

1. If Power Mode 1 is enabled, this bit is set to 0. 

The 8 least significant bits of linear acceleration sensor Z-axis output. Together with the _OUT_Z_H (2Dh)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

## **8.17 OUT_Z_H (2Dh)** 

Z-axis MSB output register (r). 

## **Table 55. OUT_Z_H register** 

Z_H7 Z_H6 Z_H5 Z_H4 Z_H3 Z_H2 Z_H1 Z_H0 

The 8 most significant bits of linear acceleration sensor Z-axis output. Together with the _OUT_Z_L (2Ch)_ register, it forms the output value expressed as a 16-bit word in 2's complement. 

## **8.18 FIFO_CTRL (2Eh)** 

FIFO control register (r/w). 

## **Table 56. FIFO_CTRL register** 

FMode2 FMode1 FMode0 FTH4 FTH3 FTH2 FTH1 FTH0 

## **Table 57. FIFO_CTRL register description** 

|FMode[2:0]|FIFO mode selection bits. Default: 000. For further details refer to_Table 58_|
|---|---|
|FTH[4:0]|FIFO threshold level setting.|



## **Table 58. FIFO mode selection** 

||**Table 58. FIFO mode selection**|
|---|---|
|**FMode[2:0]**|**Mode description**|
|000|Bypass mode: FIFO turned off|
|001|FIFO mode: Stops collecting data when FIFO is full.|
|010|Reserved|
|011|Continuous-to-FIFO: Stream mode until trigger is deasserted, then FIFO mode|
|100|Bypass-to-Continuous: Bypass mode until trigger is deasserted, then FIFO mode|
|101|Reserved|
|110|Continuous mode: If the FIFO is full, the new sample overwrites the older sample.|
|111|Reserved|



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**Register description** 

## **8.19 FIFO_SAMPLES (2Fh)** 

FIFO_SAMPLES control register (r). 

**Table 59. FIFO_SAMPLES register** 

|FIFO_<br>FTH|FIFO_<br>OVR|Diff5|Diff4|Diff3|Diff2|Diff1|Diff0|
|---|---|---|---|---|---|---|---|



## **Table 60. FIFO_SAMPLES register description** 

||**Table 60. FIFO_SAMPLES register description**|
|---|---|
|FIFO_FTH|FIFO threshold status flag.<br>(0: FIFO filling is lower than threshold level;<br>1: FIFO filling is equal to or higher than the threshold level.)|
|FIFO_OVR|FIFO overrun status.<br>(0: FIFO is not completely filled;<br>1: FIFO is completely filled and at least one sample has been overwritten)|
|Diff[5:0]|Represents the number of unread samples stored in FIFO.<br>(000000 = FIFO empty; 100000 = FIFO full, 32 unread samples).|



## **8.20 SIXD_THS (30h)** 

6D threshold register (r/w). 

## **Table 61. SIXD_THS register** 

|4D_EN|6D_THS1|6D_THS1|6D_THS0|0|0|0|0|0|
|---|---|---|---|---|---|---|---|---|
|**Table 62. SIXD_THS register description**|||||||||
|4D_EN||4D detection portrait/landscape position enable.<br>(0: no position detected;<br>1: portrait/landscape detection and face-up/face-down position enabled).|||||||
|6D_THS[1:0]||Thresholds for 4D/6D function @ FS = ±2_g_(refer to_Table 63_)|||||||



**Table 63. 4D/6D threshold setting FS @ ±2** _**g**_ 

||**Table 63. 4D/6D threshold setting FS @±2 ****_g_**|
|---|---|
|**6D_THS[1:0]**<br>00<br>01<br>10<br>11|**Threshold**|
||80 degrees|
||70 degrees|
||60 degrees|
||50 degrees|



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**Register description** 

## **8.21 WAKE_UP_THS (34h)** 

Wakeup threshold register (r/w). 

## **Table 64. WAKE_UP_THS register** 

|0|SLEEP_<br>ON|WK_THS5|WK_THS4|WK_THS3|WK_THS 2|WK_THS 1|WK_THS 0|
|---|---|---|---|---|---|---|---|



## **Table 65. WAKE_UP_THS register description** 

||**Table 65. WAKE_UP_THS register description**|
|---|---|
|SLEEP_ON|Sleep (inactivity) enable. Default value: 0<br>(0: sleep disabled; 1: sleep enabled)|
|WK_THS[5:0]|Wakeup threshold, 6-bit unsigned 1 LSB = 1/64 of FS. Default value: 000000|



## **8.22 WAKE_UP_DUR (35h)** 

Wakeup and sleep duration configuration register (r/w). 

## **Table 66. WAKE_UP_DUR register** 

|FF_DUR5|WAKE_<br>DUR1|WAKE_<br>DUR0|STATIONARY|SLEEP_<br>DUR3|SLEEP_<br>DUR2|SLEEP_<br>DUR1|SLEEP_<br>DUR0|
|---|---|---|---|---|---|---|---|



**Table 67. WAKE_UP_DUR register description** 

||**Table 67. WAKE_UP_DUR register description**|
|---|---|
|FF_DUR5|Free-fall duration. In conjunction with FF_DUR [4:0] bit in_FREE_FALL (36h)_<br>register. 1 LSB = 1 * 1/ODR|
|WAKE_DUR[1:0]|Wakeup duration. 1 LSB = 1 *1/ODR|
|STATIONARY|Enable stationary detection / motion detection with no automatic ODR change<br>when detecting stationary state. Default value: 0<br>(0: disabled; 1: enabled)|
|SLEEP_ DUR[3:0]|Duration to go in sleep mode.<br>Default value is SLEEP_ DUR[3:0] = 0000 (which is 16 * 1/ODR)<br>1 LSB = 512 * 1/ODR|



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**Register description** 

## **8.23 FREE_FALL (36h)** 

Free-fall duration and threshold configuration register (r/w). 

## **Table 68. FREE_FALL register** 

FF_DUR4 FF_DUR3 FF_DUR2 FF_DUR1 FF_DUR0 FF_THS2 FF_THS1 FF_THS0 

## **Table 69. FREE_FALL register description** 

Free-fall duration. In conjunction with FF_DUR5 bit in _WAKE_UP_DUR (35h)_ FF_DUR [4:0] register. 1 LSB = 1 * 1/ODR FF_THS [2:0] Free-fall threshold @ FS = ±2 _g_ (refer to _Table 70_ ) 

**Table 70. FREE_FALL threshold decoding @ ±2** _**g**_ **FS** 

|**FF_THS[2:0]**|**Threshold decoding (LSB)**|
|---|---|
|000|5|
|001|7|
|010|8|
|011|10|
|100|11|
|101|13|
|110|15|
|111|16|



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**Register description** 

## **8.24 STATUS_DUP (37h)** 

Event detection status register (r). 

**Table 71. STATUS_DUP register** 

|OVR|DRDY_T|DRDY_T|SLEEP_<br>STATE_IA|0|0|6D_IA|FF_IA|DRDY|
|---|---|---|---|---|---|---|---|---|
|**Table 72. STATUS_DUP register description**|||||||||
|OVR||FIFO overrun status flag.<br>(0: FIFO is not completely filled;<br>1: FIFO is completely filled and at least one sample has been overwritten)|||||||
|DRDY_T||Temperature status.<br>(0: data not available; 1: a new set of data is available)|||||||
|SLEEP_<br>STATE_IA||Sleep event status.<br>(0: Sleep event not detected; 1: Sleep event detected)|||||||
|6D_IA||Source of change in position portrait/landscape/face-up/face-down.<br>(0: no event detected; 1: a change in position is detected)|||||||
|FF_IA||Free-fall event detection status.<br>(0: free-fall event not detected; 1: free-fall event detected)|||||||
|DRDY||Data-ready status.<br>(0: not ready; 1: X-, Y- and Z-axis new data available)|||||||



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**Register description** 

## **8.25 WAKE_UP_SRC (38h)** 

Wakeup source register (r). 

## **Table 73. WAKE_UP_SRC register** 

|0|0|FF_IA|SLEEP_<br>STATE IA|WU_IA|X_WU|Y_WU|Z_WU|
|---|---|---|---|---|---|---|---|



## **Table 74. WAKE_UP_SRC register description** 

||**Table 74. WAKE_UP_SRC register description**|
|---|---|
|FF_IA|Free-fall event detection status.<br>(0: FF event not detected; 1: FF event detected)|
|SLEEP_<br>STATE IA|Sleep event status.<br>(0: Sleep event not detected; 1: Sleep event detected)|
|WU_IA|Wakeup event detection status.<br>(0: Wakeup event not detected; 1: Wakeup event is detected)|
|X_WU|Wakeup event detection status on X-axis.<br>(0: Wakeup event on X not detected; 1: Wakeup event on X-axis is detected)|
|Y_WU|Wakeup event detection status on Y-axis.<br>(0: Wakeup event on Y not detected; 1: Wakeup event on Y-axis is detected)|
|Z_WU|Wakeup event detection status on Z-axis.<br>(0: Wakeup event on Z not detected; 1: Wakeup event on Z-axis is detected)|



## **8.26 SIXD_SRC (3Ah)** 

6D source register (r). 

**Table 75. SIXD_SRC register** 

0 6D_IA ZH ZL YH YL XH XL 

## **Table 76. SIXD_SRC register description** 

Source of change in position portrait/landscape/face-up/face-down. 6D_IA (0: no event detected; 1: a change in position is detected) ZH over threshold. ZH (0: ZH does not exceed the threshold; 1: ZH is over the threshold) ZL over threshold. ZL (0: ZL does not exceed the threshold; 1: ZL is over the threshold) YH over threshold. YH (0: YH does not exceed the threshold; 1: YH is over the threshold) YL over threshold. YL (0: YL does not exceed the threshold; 1: YL is over the threshold) XH over threshold. XH (0: XH does not exceed the threshold; 1: XH is over the threshold) XL over threshold. XL (0: XL does not exceed the threshold; 1: XL is over the threshold) 

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**Register description** 

## **8.27 ALL_INT_SRC (3Bh)** 

Reading this register, all related interrupt function flags routed to the INT pads are reset simultaneously. 

**Table 77. ALL_INT_SRC register** 

|0|0|SLEEP_<br>CHANGE_IA|6D_IA|0|0|WU_IA|FF_IA|
|---|---|---|---|---|---|---|---|



**Table 78. ALL_INT_SRC register description** 

|SLEEP_<br>CHANGE_IA|Sleep change status.<br>(0: Sleep change not detected; 1: Sleep change detected)|
|---|---|
|6D_IA|Source of change in position portrait/landscape/face-up/face-down.<br>(0: no event detected; 1: a change in position detected)|
|WU_IA|Wakeup event detection status.<br>(0: wakeup event not detected; 1: wakeup event detected)|
|FF_IA|Free-fall event detection status.<br>(0: free-fall event not detected; 1: free-fall event detected)|



## **8.28 X_OFS_USR (3Ch)** 

Accelerometer X-axis user offset correction (r/w). The offset value set in the X_OFS_USR offset register is internally subtracted from the acceleration value measured on the X-axis. 

**Table 79. X_OFS_USR register** 

|X_OFS_<br>USR_7|X_OFS_<br>USR_6|X_OFS_<br>USR_5|X_OFS_<br>USR_4|X_OFS_<br>USR_3|X_OFS_<br>USR_2|X_OFS_<br>USR_1|X_OFS_<br>USR_0|
|---|---|---|---|---|---|---|---|



## **Table 80. X_OFS_USR register description** 

|X_OFS_USR_[7:0]|Accelerometer X-axis user offset correction expressed in two’s complement,<br>weight depends on the USR_OFF_W bit in_CTRL7 (3Fh)_. The value must be<br>in the range [-127 127].|
|---|---|



## **8.29 Y_OFS_USR (3Dh)** 

Accelerometer Y-axis user offset correction (r/w). The offset value set in the Y_OFS_USR offset register is internally subtracted from the acceleration value measured on the Y-axis. 

**Table 81. Y_OFS_USR register** 

|Y_OFS_<br>USR_7|Y_OFS_<br>USR_6|Y_OFS_<br>USR_6|Y_OFS_<br>USR_5|Y_OFS_<br>USR_4|Y_OFS_<br>USR_3|Y_OFS_<br>USR_2|Y_OFS_<br>USR_1|Y_OFS_<br>USR_0|
|---|---|---|---|---|---|---|---|---|
|**Table 82. Y_OFS_USR register description**|||||||||
|Y_OFS_USR_[7:0]||Accelerometer Y-axis user offset correction expressed in two’s complement,<br>weight depends on the USR_OFF_W bit in_CTRL7 (3Fh)_. The value must be<br>in the range [-127 127].|||||||



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**Register description** 

## **8.30 Z_OFS_USR (3Eh)** 

Accelerometer Z-axis user offset correction (r/w). The offset value set in the Z_OFS_USR offset register is internally subtracted from the acceleration value measured on the Z-axis. 

**Table 83. Z_OFS_USR register** 

|Z_OFS_<br>USR_7|Z_OFS_<br>USR_6|Z_OFS_<br>USR_5|Z_OFS_<br>USR_4|Z_OFS_<br>USR_3|Z_OFS_<br>USR_2|Z_OFS_<br>USR_1|Z_OFS_<br>USR_0|
|---|---|---|---|---|---|---|---|



## **Table 84. Z_OFS_USR register description** 

Accelerometer Z-axis user offset correction expressed in two’s complement, Z_OFS_USR_[7:0] weight depends on the USR_OFF_W bit in _CTRL7 (3Fh)_ . The value must be in the range [-127 127]. 

## **8.31 CTRL7 (3Fh)** 

**Table 85. CTRL7 register** 

|DRDY_<br>PULSED|INT2_ON<br>_INT1|INTERRUPTS<br>_ENABLE|USR_OFF<br>_ON_OUT|USR_OFF<br>_ON_WU|USR_OFF<br>_W|HP_REF<br>_MODE|LPASS_<br>ON6D|
|---|---|---|---|---|---|---|---|



**Table 86. CTRL7 register description** 

||**Table 86. CTRL7 register description**|
|---|---|
|DRDY_<br>PULSED|Switches between latched and pulsed mode for data ready interrupt.<br>(0: latched mode is used; 1: pulsed mode enabled for data-ready)|
|INT2_ON_INT1|Signal routing.<br>(1: all signals available only on INT2 are routed on INT1)|
|INTERRUPTS_<br>ENABLE|Enable interrupts.|
|USR_OFF<br>_ON_OUT|Enable application of user offset value on XL output data registers.<br>FDS bit in_CTRL6 (25h)_must be set to '0'-logic (low-pass path selected).|
|USR_OFF<br>_ON_WU|Enable application of user offset value on XL data for wakeup function only.|
|USR_OFF_W|Selects the weight of the user offset words specified by X_OFS_USR_[7:0],<br>Y_OFS_USR_[7:0] and Z_OFS_USR_[7:0] bits.<br>(0: 977 μ_g_/LSB; 1: 15.6 m_g_/LSB)|
|HP_REF_MODE|High-pass filter reference mode enable.<br>(0: high-pass filter reference mode disabled (default);<br>1: high-pass filter reference mode enabled)|
|LPASS_ON6D|(0: ODR/2 low pass filtered data sent to 6D interrupt function (default);<br>1: LPF2 output data sent to 6D interrupt function)|



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## **9 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. 

## **9.1 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-020. 

Land pattern and soldering recommendations are available at www.st.com. 

## **9.2 LGA-12 package information** 

**Figure 18. LGA-12 2.0 x 2.0 x 0.93 mm package outline and mechanical data** 

**==> picture [180 x 40] intentionally omitted <==**

**----- Start of picture text -----**<br>
tM<br>0.100min Po<br>0.070 minimum Po<br>0.025 minimum ee<br>**----- End of picture text -----**<br>


**==> picture [23 x 8] intentionally omitted <==**

**----- Start of picture text -----**<br>
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**Package information** 

## **9.3 LGA-12 packing information** 

**Figure 19. Carrier tape information for LGA-12 package** 

**Figure 20. LGA-12 package orientation in carrier tape** 

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**Figure 21. Reel information for carrier tape of LGA-12 package** 

**Table 87. Reel dimensions for carrier tape of LGA-12 package** 

||**Reel dimensions (mm)**|**Reel dimensions (mm)**||
|---|---|---|---|
|A (max)|||330|
|B (min)|||1.5|
|C|||13 ±0.25|
|D (min)|||20.2|
|N (min)|||60|
|G|||12.4 +2/-0|
|T (max)|||18.4|



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**Revision history** 

## **10 Revision history** 

**Table 88. Document revision history** 

|||**Table 88. Document revision history**|
|---|---|---|
|**Date**|**Revision**|**Changes**|
|05-Jun-2019|3|First public release|
|20-Jun-2019|4|Updated_Table 10: Absolute maximum ratings_|



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## **IMPORTANT NOTICE – PLEASE READ CAREFULLY** 

STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. 

Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. 

No license, express or implied, to any intellectual property right is granted by ST herein. 

Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. 

ST and the ST logo are trademarks of ST. For additional information about ST trademarks, please refer to _www.st.com/trademarks_ . All other product or service names are the property of their respective owners. 

Information in this document supersedes and replaces information previously supplied in any prior versions of this document. 

© 2019 STMicroelectronics – All rights reserved 

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