EVAL-ADXL313-Z [ADI]

3-Axis, ±0.5 g/±1 g/±2 g/±4 g Digital Accelerometer; 3轴, ±0.5克/ ±1克/ ±2克/ ± 4克数字加速度计
EVAL-ADXL313-Z
型号: EVAL-ADXL313-Z
厂家: ADI    ADI
描述:

3-Axis, ±0.5 g/±1 g/±2 g/±4 g Digital Accelerometer
3轴, ±0.5克/ ±1克/ ±2克/ ± 4克数字加速度计

文件: 总28页 (文件大小:598K)
中文:  中文翻译
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3-Axis, 0.5 g/ 1 g/ 2 g/ 4 g  
Digital Accelerometer  
Data Sheet  
ADXL313  
FEATURES  
GENERAL DESCRIPTION  
Ultralow power (scales automatically with data rate)  
As low as 30 µA in measurement mode (VS = 3.3 V)  
As low as 0.1 µA in standby mode (VS = 3.3 V)  
Low noise performance  
150 μg/√Hz typical for X- and Y-axes  
250 μg/√Hz typical for the Z-axis  
Embedded, patent pending FIFO technology minimizes host  
processor load  
User-selectable resolution  
Fixed 10-bit resolution for any g range  
Fixed 1024 LSB/g sensitivity for any g range  
Resolution scales from 10-bit at 0.5 g to 13-bit at 4 g  
Built-in motion detection functions for activity/inactivity  
monitoring  
Supply and I/O voltage range: 2.0 V to 3.6 V  
SPI (3-wire and 4-wire) and I2C digital interfaces  
Flexible interrupt modes mappable to two interrupt pins  
Measurement range selectable via serial command  
Bandwidth selectable via serial command  
Wide temperature range (−40°C to +105°C)  
10,000 g shock survival  
The ADXL313 is a small, thin, low power, 3-axis accelerometer  
with high resolution (13-bit) measurement up to 4 g. Digital  
output data is formatted as 16-bit twos complement and is  
accessible through either a serial port interface (SPI) (3-wire or  
4-wire) or I2C digital interface.  
The ADXL313 is well suited for car alarm or black box applications.  
It measures the static acceleration of gravity in tilt-sensing applica-  
tions, as well as dynamic acceleration resulting from motion or  
shock. Its high resolution (1024 LSB/g) and low noise (150 μg/√Hz)  
enable resolution of inclination changes of as little as 0.1°. A built-  
in FIFO facilitates using oversampling techniques to improve  
resolution to as little as 0.025° of inclination.  
Several built-in sensing functions are provided. Activity and  
inactivity sensing detects the presence or absence of motion and  
whether the acceleration on any axis exceeds a user-set level.  
These functions can be mapped to interrupt output pins. An  
integrated 32-level FIFO can be used to store data to minimize  
host processor intervention, resulting in reduced system power  
consumption.  
Low power modes enable intelligent motion-based power  
management with threshold sensing and active acceleration  
measurement at extremely low power dissipation.  
Pb free/RoHS compliant  
Small and thin: 5 mm × 5 mm × 1.45 mm LFCSP package  
Qualified for automotive applications  
The ADXL313 is supplied in a small, thin 5 mm × 5 mm ×  
1.45 mm, 32-lead LFCSP package and is pin compatible with  
the ADXL312 accelerometer device.  
APPLICATIONS  
Car alarms  
Hill start aid (HSA) systems  
Electronic parking brakes  
Data recorders (black boxes)  
FUNCTIONAL BLOCK DIAGRAM  
V
V
DD I/O  
S
ADXL313  
POWER  
MANAGEMENT  
INT1  
INT2  
CONTROL  
AND  
INTERRUPT  
LOGIC  
DIGITAL  
FILTER  
SENSE  
ELECTRONICS  
ADC  
3-AXIS  
SENSOR  
SDA/SDI/SDIO  
32-LEVEL  
FIFO  
SERIAL I/O  
SDO/ALT  
ADDRESS  
SCL/SCLK  
GND  
CS  
Figure 1.  
Rev. 0  
Document Feedback  
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responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
rights of third parties that may result from its use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks and registered trademarks are the property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700  
Technical Support  
©2013 Analog Devices, Inc. All rights reserved.  
www.analog.com  
 
 
 
 
ADXL313  
Data Sheet  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
FIFO............................................................................................. 15  
Self Test........................................................................................ 16  
Register Map ................................................................................... 17  
Register Definitions ................................................................... 18  
Applications Information.............................................................. 22  
Power Supply Decoupling ......................................................... 22  
Mechanical Considerations for Mounting.............................. 22  
Threshold .................................................................................... 22  
Link Mode................................................................................... 22  
Sleep Mode vs. Low Power Mode............................................. 22  
Using Self Test............................................................................. 23  
3200 Hz and 1600 Hz ODR Data Formatting ........................ 24  
Axes of Acceleration Sensitivity ............................................... 25  
Solder Profile................................................................................... 26  
Outline Dimensions....................................................................... 27  
Ordering Guide .......................................................................... 28  
Automotive Products................................................................. 28  
Applications....................................................................................... 1  
General Description......................................................................... 1  
Functional Block Diagram .............................................................. 1  
Revision History ............................................................................... 2  
Specifications..................................................................................... 3  
Absolute Maximum Ratings............................................................ 4  
Thermal Resistance ...................................................................... 4  
ESD Caution.................................................................................. 4  
Pin Configuration and Function Descriptions............................. 5  
Typical Performance Characteristics ............................................. 6  
Theory of Operation ........................................................................ 8  
Power Sequencing ........................................................................ 8  
Power Savings ............................................................................... 8  
Serial Communications ................................................................. 10  
SPI................................................................................................. 10  
I2C................................................................................................. 13  
Interrupts..................................................................................... 15  
REVISION HISTORY  
4/13—Revision 0: Initial Version  
Rev. 0 | Page 2 of 28  
 
Data Sheet  
ADXL313  
SPECIFICATIONS  
TA = −40°C to +105°C, VS = VDD I/O = 3.3 V, a cceleration = 0 g, unless otherwise noted.  
Table 1.  
Parameter1  
Test Conditions/Comments  
Each axis  
Min  
Typ  
Max  
Unit  
SENSOR INPUT  
Measurement Range  
Nonlinearity  
User selectable  
±0.5, ±1, ±2, ±4  
g
Percentage of full scale  
Measured over any 50 mg interval  
±0.5  
±2  
%
Micro-Nonlinearity  
Interaxis Alignment Error  
Cross-Axis Sensitivity2  
OUTPUT RESOLUTION  
All g Ranges  
%
±0.1  
±1  
Degrees  
%
Each axis  
Default resolution  
10  
10  
11  
12  
13  
Bits  
Bits  
Bits  
Bits  
Bits  
±0.5 g Range  
Full resolution enabled  
Full resolution enabled  
Full resolution enabled  
Full resolution enabled  
Each axis  
±1 g Range  
±2 g Range  
±4 g Range  
SENSITIVITY  
Sensitivity at XOUT, YOUT, ZOUT  
Any g-range, full resolution mode  
±0.5 g, 10-bit or full resolution  
±1 g, 10-bit resolution  
±2 g, 10-bit resolution  
±4 g, 10-bit resolution  
1024  
1024  
512  
LSB/g  
LSB/g  
LSB/g  
LSB/g  
LSB/g  
%/°C  
921  
460  
230  
115  
1126  
563  
282  
141  
256  
128  
Sensitivity Change Due to Temperature  
0 g BIAS LEVEL  
±0.01  
Each axis  
Initial 0 g Output  
T = 25°C, XOUT, YOUT  
±50  
±±5  
mg  
T = 25°C, ZOUT  
mg  
0 g Output Drift over Temperature  
0 g Offset Tempco  
−40°C < T < +105°C, XOUT, YOUT, referenced to initial 0 g output  
−125  
−200  
+125  
+200  
mg  
−40°C < T < +105°C, ZOUT, referenced to initial 0 g output  
mg  
XOUT, YOUT  
ZOUT  
±0.5  
mg/°C  
mg/°C  
±0.±5  
NOISE PERFORMANCE  
Noise Density  
X-, Y-axes  
150  
250  
1.5  
µg/√Hz  
µg/√Hz  
mg rms  
mg rms  
Z-axis  
RMS Noise  
X-, Y-axes, 100 Hz output data rate (ODR)  
Z-axis, 100 Hz ODR  
User selectable  
2.5  
OUTPUT DATA RATE/BANDWIDTH  
Measurement Rate3  
6.25  
3200  
Hz  
SELF TEST4  
Data rate ≥ 100 Hz, 2.0 V ≤ VS ≤ 3.6 V  
Output Change in X-Axis  
Output Change in Y-Axis  
Output Change in Z-Axis  
POWER SUPPLY  
0.20  
2.36  
g
g
g
−2.36  
0.30  
−0.20  
3.±0  
Operating Voltage Range (VS)  
2.0  
1.±  
100  
30  
3.6  
VS  
V
Interface Voltage Range (VDD I/O  
)
V
Supply Current  
Data rate > 100 Hz  
Data rate < 10 Hz  
1±0  
55  
300  
110  
2
µA  
µA  
µA  
ms  
Standby Mode Leakage Current  
Turn-On (Wake-Up) Time5  
TEMPERATURE  
0.1  
1.4  
Operating Temperature Range  
−40  
+105  
°C  
1 All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed.  
2 Cross-axis sensitivity is defined as coupling between any two axes.  
3 Bandwidth is half the output data rate.  
4 Self test change is defined as the output (g) when the SELF_TEST bit = 1 (in the DATA_FORMAT register, Address 0x31) minus the output (g) when the SELF_TEST bit =  
0 (in the DATA_FORMAT register). Due to device filtering, the output reaches its final value after 4 × τ when enabling or disabling self test, where τ = 1/(data rate).  
5 Turn-on and wake-up times are determined by the user-defined bandwidth. At a 100 Hz data rate, the turn-on and wake-up times are each approximately 11.1 ms. For  
other data rates, the turn-on and wake-up times are each approximately τ + 1.1 in milliseconds, where τ = 1/(data rate).  
Rev. 0 | Page 3 of 28  
 
 
 
 
 
 
 
ADXL313  
Data Sheet  
ABSOLUTE MAXIMUM RATINGS  
Table 2.  
THERMAL RESISTANCE  
Parameter  
Acceleration  
Any Axis, Unpowered  
Any Axis, Powered  
VS  
Rating  
θJA is specified for the worst-case conditions, that is, a device  
soldered in a circuit board for surface-mount packages.  
10,000 g  
10,000 g  
−0.3 V to +3.9 V  
−0.3 V to +3.9 V  
Table 3. Thermal Resistance  
Package Type  
θJA  
θJC  
Unit  
32-Lead LFCSP Package  
2±.2±  
30  
°C/W  
VDD I/O  
All Other Pins  
−0.3 V to VDD I/O + 0.3 V or 3.9 V,  
whichever is less  
ESD CAUTION  
Output Short-Circuit Duration  
(Any Pin to Ground)  
Indefinite  
Temperature Range  
Powered  
Storage  
−40°C to +125°C  
−40°C to +125°C  
Stresses above those listed under Absolute Maximum Ratings  
may cause permanent damage to the device. This is a stress  
rating only; functional operation of the device at these or any  
other conditions above those indicated in the operational  
section of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect  
device reliability.  
Rev. 0 | Page 4 of 28  
 
 
 
Data Sheet  
ADXL313  
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS  
GND  
RESERVED  
GND  
1
2
3
4
5
6
7
8
24 SDA/SDI/SDIO  
23  
22 RESERVED  
21 INT2  
SDO/ALT ADDRESS  
ADXL313  
TOP VIEW  
(Not to Scale)  
GND  
20  
19  
V
INT1  
NC  
S
CS  
RESERVED  
NC  
18 NC  
17 NC  
NOTES  
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.  
2. THE EXPOSED PAD MUST BE SOLDERED TO THE GROUND PLANE.  
Figure 2. Pin Configuration  
Table 4. Pin Function Descriptions  
Pin No.  
Mnemonic  
Description  
1
2
3
4
GND  
RESERVED  
GND  
GND  
This pin must be connected to ground.  
Reserved. This pin must be connected to VS or left open.  
This pin must be connected to ground.  
This pin must be connected to ground.  
Supply Voltage.  
5
VS  
6
CS  
Chip Select.  
±
RESERVED  
NC  
INT1  
Reserved. This pin must be left open.  
No Connect. Do not connect to this pin.  
Interrupt 1 Output.  
8 to 19  
20  
21  
INT2  
Interrupt 2 Output.  
22  
23  
24  
RESERVED  
SDO/ALT ADDRESS  
SDA/SDI/SDIO  
Reserved. This pin must be connected to GND or left open.  
Serial Data Output/Alternate I2C Address Select.  
Serial Data (I2C)/Serial Data Input (SPI 4-Wire)/Serial Data Input/Output (SPI 3-Wire).  
25  
26  
2± to 30  
31  
32  
NC  
SCL/SCLK  
NC  
VDD I/O  
NC  
No Connect. Do not connect to this pin.  
I2C Serial Communications Clock/SPI Serial Communications Clock.  
No Connect. Do not connect to this pin.  
Digital Interface Supply Voltage.  
No Connect. Do not connect to this pin.  
EP  
Exposed Pad. The exposed pad must be soldered to the ground plane.  
Rev. 0 | Page 5 of 28  
 
ADXL313  
Data Sheet  
TYPICAL PERFORMANCE CHARACTERISTICS  
40  
30  
1.0  
0.5  
0
125  
100  
75  
20  
50  
10  
25  
0
0
–25  
–50  
–75  
–100  
–125  
–10  
–20  
–30  
–40  
–0.5  
–1.0  
–2000 –1500 –1000 –500  
0
500  
1000  
1500  
2000  
–50  
–30  
–10  
10  
30  
50  
70  
90  
110  
INPUT ACCELERATION (mg)  
TEMPERATURE (°C)  
Figure 6. X-Axis Nonlinearity, 2 g Input Range  
Figure 3. X-Axis Acceleration vs. Temperature, Three Lots (N = 80)  
125  
100  
75  
40  
30  
1.0  
20  
0.5  
0
50  
10  
25  
0
0
–25  
–50  
–75  
–100  
–125  
–10  
–20  
–30  
–40  
–0.5  
–1.0  
–50  
–30  
–10  
10  
30  
50  
70  
90  
110  
–2000 –1500 –1000 –500  
0
500  
1000  
1500  
2000  
INPUT ACCELERATION (mg)  
TEMPERATURE (°C)  
Figure 4. Y-Axis Acceleration vs. Temperature, Three Lots (N = 80)  
Figure 7. Y-Axis Nonlinearity, 2 g Input Range  
200  
150  
100  
50  
40  
30  
1.0  
0.5  
0
20  
10  
0
0
–50  
–100  
–150  
–200  
–10  
–20  
–30  
–40  
–0.5  
–1.0  
–50  
–30  
–10  
10  
30  
50  
70  
90  
110  
–2000 –1500 –1000 –500  
0
500  
1000  
1500  
2000  
TEMPERATURE (°C)  
INPUT ACCELERATION (mg)  
Figure 5. Z-Axis Acceleration vs. Temperature, Three Lots (N = 80)  
Figure 8. Z-Axis Nonlinearity, 2 g Input Range  
Rev. 0 | Page 6 of 28  
 
Data Sheet  
ADXL313  
5
80  
70  
60  
50  
40  
30  
20  
10  
0
4
3
2
1
0
–1  
–2  
–3  
–4  
–5  
–1000 –750  
–500  
–250  
0
250  
500  
750  
1000  
INPUT ACCELERATION (mg)  
CURRENT (nA)  
Figure 9. X-Axis Microlinearity, 50 mg Step Size  
Figure 12. Standby Mode Current Consumption, VS = VDD I/O = 3.3 V, 25°C  
5
4
35  
30  
25  
20  
15  
10  
5
3
2
1
0
–1  
–2  
–3  
–4  
–5  
0
–1000 –750  
–500  
–250  
0
250  
500  
750  
1000  
INPUT ACCELERATION (mg)  
CURRENT CONSUMPTION (µA)  
Figure 10. Y-Axis Microlinearity, 50 mg Step Size  
Figure 13. Current Consumption, Measurement Mode, Data Rate = 100 Hz,  
VS = VDD I/O = 3.3 V, 25°C  
5
4
200  
150  
100  
50  
3
2
1
0
–1  
–2  
–3  
–4  
–5  
0
–1000 –750  
–500  
–250  
0
250  
500  
750  
1000  
2.0  
2.4  
2.8  
3.2  
3.6  
INPUT ACCELERATION (mg)  
SUPPLY VOLTAGE (V)  
Figure 14. Supply Current vs. Supply Voltage, VS at 25°C  
Figure 11. Z-Axis Microlinearity, 50 mg Step Size  
Rev. 0 | Page ± of 28  
ADXL313  
Data Sheet  
THEORY OF OPERATION  
The ADXL313 is a complete 3-axis acceleration measurement  
system with a selectable measurement range of 0.5 g, 1 g,  
2 g, or 4 g. It measures both dynamic acceleration resulting  
from motion or shock and static acceleration, such as gravity,  
which allows it to be used as a tilt sensor.  
POWER SAVINGS  
Power Modes  
The ADXL313 automatically modulates its power consumption  
in proportion to its output data rate, as outlined in Table 5. If  
additional power savings are desired, a lower power mode is  
available. In this mode, the internal sampling rate is reduced,  
allowing for power savings in the 12.5 Hz to 400 Hz data rate  
range at the expense of slightly greater noise. To enter low  
power mode, set the LOW_POWER bit (Bit 4) in the BW_RATE  
register (Address 0x2C). The current consumption in low power  
mode is shown in Table 6 for cases where there is an advantage  
to using low power mode. Use of low power mode for a data  
rate not shown in Table 6 does not provide any advantage over  
the same data rate in normal power mode. Therefore, it is  
recommended that only data rates shown in Table 6 be used in  
low power mode. The current consumption values shown in  
Table 5 and Table 6 are for a VS of 3.3 V.  
The sensor is a polysilicon surface-micromachined structure  
built on top of a silicon wafer. Polysilicon springs suspend the  
structure over the surface of the wafer and provide a resistance  
against acceleration forces.  
Deflection of the structure is measured using differential  
capacitors that consist of independent fixed plates and plates  
attached to the moving mass. Acceleration deflects the beam  
and unbalances the differential capacitor, resulting in a sensor  
output whose amplitude is proportional to acceleration. Phase-  
sensitive demodulation is used to determine the magnitude and  
polarity of the acceleration.  
POWER SEQUENCING  
Table 5. Current Consumption vs. Data Rate  
(TA = 25°C, VS = VDD I/O = 3.3 V)  
Output Data  
Power can be applied to VS or VDD I/O in any sequence without  
damaging the ADXL313. All possible power-on modes are  
summarized in Table 5. The interface voltage level is set with  
the interface supply voltage, VDD I/O, which must be present to  
ensure that the ADXL313 does not create a conflict on the  
communication bus. For single-supply operation, VDD I/O can be  
the same as the main supply, VS. In a dual-supply application,  
however, VDD I/O can differ from VS to accommodate the desired  
Rate (Hz)  
3200  
1600  
800  
Bandwidth (Hz)  
Rate Code  
IDD (µA)  
1±0  
115  
1±0  
1±0  
1±0  
1±0  
115  
82  
1600  
800  
400  
200  
100  
50  
1111  
1110  
1101  
400  
1100  
200  
1011  
interface voltage, as long as VS is greater than or equal to VDD I/O  
.
100  
1010  
After VS is applied, the device enters standby mode, where power  
consumption is minimized and the device waits for VDD I/O to be  
applied and for the command to enter measurement mode to be  
received. (This command can be initiated by setting the measure  
bit in the POWER_CTL register (Address 0x2D).) In addition, any  
register can be written to or read from to configure the part while  
the device is in standby mode. It is recommended that the device  
be configured in standby mode before measurement mode is  
enabled. Clearing the measure bit returns the device to the standby  
mode.  
50  
25  
12.5  
6.25  
25  
1001  
1000  
0111  
0110  
12.5  
6.25  
3.125  
65  
5±  
Table 6. Current Consumption vs. Data Rate, Low Power Mode  
(TA = 25°C, VS = VDD I/O = 3.3 V)  
Output Data  
Rate (Hz)  
Bandwidth (Hz)  
Rate Code  
1100  
1011  
IDD (µA)  
115  
82  
400  
200  
100  
200  
100  
50  
1010  
65  
50  
25  
1001  
5±  
25  
12.5  
12.5  
6.25  
1000  
0111  
50  
43  
Table 7. Power Sequencing  
Condition  
VS  
VDD I/O  
Description  
The device is completely off, but there is a potential for a communication bus conflict.  
The device is on in standby mode, but communication is unavailable, and the device creates a conflict  
on the communication bus. Minimize the duration of this state during power-up to prevent a conflict.  
Power Off  
Bus Disabled  
Off  
On  
Off  
Off  
Bus Enabled  
Standby or  
Measurement  
Off  
On  
On  
On  
No functions are available, but the device does not create a conflict on the communication bus.  
The device is in standby mode, awaiting a command to enter measurement mode, and all sensor  
functions are off. After the device is instructed to enter measurement mode, all sensor functions are  
available.  
Rev. 0 | Page 8 of 28  
 
 
 
 
 
 
Data Sheet  
ADXL313  
Autosleep Mode  
Standby Mode  
Additional power savings can be obtained by having the  
ADXL313 automatically switch to sleep mode during periods of  
inactivity. To enable this feature, set the THRESH_INACT  
register (Address 0x25) to an acceleration threshold value.  
Levels of acceleration below this threshold are regarded as no  
activity. Set TIME_INACT (Address 0x26) to an appropriate  
inactivity time period. Then set the AUTO_SLEEP bit and the  
link bit in the POWER_CTL register (Address 0x2D). If the  
device does not detect a level of acceleration in excess of  
THRESH_INACT for TIME_INACT seconds, the device is  
transitioned to sleep mode automatically. Current consumption  
at less than 10 Hz data rates used in this mode is typically 55 µA  
for a VS of 3.3 V.  
For even lower power operation, standby mode can be used.  
In standby mode, current consumption is reduced to 0.1 µA  
(typical). In this mode, no measurements are made. Standby  
mode is entered by clearing the measure bit (Bit 3) in the  
POWER_CTL register (Address 0x2D). Placing the device into  
standby mode preserves the contents of the FIFO.  
Rev. 0 | Page 9 of 28  
ADXL313  
Data Sheet  
SERIAL COMMUNICATIONS  
I2C and SPI digital communications are available. In both cases,  
CS  
is the serial port enable line and is controlled by the SPI master.  
2
CS  
the ADXL313 operates as a slave. I C mode is enabled if the pin  
This line must go low at the start of a transmission and high at  
the end of a transmission, as shown in Figure 17 to Figure 19.  
SCLK is the serial port clock and is supplied by the SPI master.  
SCLK idles high during a period of no transmission. SDI and  
SDO are the serial data input and output, respectively. Data is  
updated on the falling edge of SCLK and sampled on the rising  
edge of SCLK.  
CS  
is tied high to VDD I/O. The  
pin must always be tied high to  
VDD I/O or be driven by an external controller because there is no  
CS  
default mode if the  
pin is left unconnected. Therefore, not  
taking these precautions may result in an inability to communicate  
CS  
with the part. In SPI mode, the  
pin is controlled by the bus  
master. In both SPI and I2C modes of operation, ignore data  
transmitted from the ADXL313 to the master device during  
writes to the ADXL313.  
To read or write multiple bytes in a single transmission, the  
W
multiple-byte bit, located after the R/ bit in the first byte transfer  
(MB in Figure 17 to Figure 19), must be set. After the register  
addressing and the first byte of data, each subsequent set of  
clock pulses (eight clock pulses) causes the ADXL313 to point  
to the next register for a read or write. This shifting continues  
SPI  
For SPI communication, either 3- or 4-wire configuration is  
possible, as shown in the connection diagrams in Figure 15 and  
Figure 16. Clearing the SPI bit in the DATA_FORMAT register  
(Address 0x31) selects 4-wire mode, whereas setting the SPI bit  
selects 3-wire mode. The maximum SPI clock speed is 5 MHz  
with 100 pF maximum loading, and the timing scheme follows  
clock polarity (CPOL) = 1 and clock phase (CPHA) = 1. If power  
is applied to the ADXL313 before the clock polarity and phase  
CS  
until the clock pulses cease and is deasserted. To perform reads  
CS  
or writes on different, nonsequential registers,  
must be  
deasserted between transmissions, and the new register must be  
addressed separately.  
The timing diagram for 3-wire SPI reads or writes is shown in  
Figure 17. The 4-wire equivalents for SPI reads and writes are  
shown in Figure 18 and Figure 19, respectively. For correct  
operation of the part, the logic thresholds and timing parameters  
in Table 8 and Table 9 must be met at all times.  
CS  
of the host processor are configured, the pin must be brought  
high before changing the clock polarity and phase. When using  
the 3-wire SPI configuration, it is recommended that the SDO  
pin be either pulled up to VDD I/O or pulled down to GND via a  
10 kΩ resistor.  
Use of the 3200 Hz and 1600 Hz output data rates is recommended  
only with SPI communication rates greater than or equal to 2  
MHz. The 800 Hz output data rate is recommended only for  
communication speeds greater than or equal to 400 kHz, and  
the remaining data rates scale proportionally. For example, the  
minimum recommended communication speed for a 200 Hz  
output data rate is 100 kHz. Operation at an output data rate  
below the recommended minimum may result in undesirable  
effects on the acceleration data, including missing samples or  
additional noise.  
ADXL313  
PROCESSOR  
CS  
SDIO  
SDO  
D OUT  
D IN/OUT  
SCLK  
D OUT  
Figure 15. 3-Wire SPI Connection Diagram  
ADXL313  
PROCESSOR  
CS  
SDI  
D OUT  
D OUT  
D IN  
SDIO  
SCLK  
D OUT  
Figure 16. 4-Wire SPI Connection Diagram  
Rev. 0 | Page 10 of 28  
 
 
 
 
Data Sheet  
ADXL313  
Table 8. SPI Digital Input/Output  
Limit1  
Max  
Parameter  
Test Conditions/Comments  
Min  
Unit  
Digital Input  
Low Level Input Voltage (VIL)  
High Level Input Voltage (VIH)  
Low Level Input Current (IIL)  
High Level Input Current (IIH)  
Digital Output  
0.3 × VDD I/O  
0.1  
V
V
µA  
µA  
0.± × VDD I/O  
−0.1  
VIN = VDD I/O  
VIN = 0 V  
Low Level Output Voltage (VOL)  
High Level Output Voltage (VOH)  
Low Level Output Current (IOL)  
High Level Output Current (IOH)  
Pin Capacitance  
IOL = 10 mA  
IOH = −4 mA  
VOL = VOL, max  
VOH = VOH, min  
0.2 × VDD I/O  
V
V
mA  
mA  
pF  
0.8 × VDD I/O  
10  
−4  
8
fIN = 1 MHz, VIN = 2.5 V  
1 Limits based on characterization results; not production tested.  
Table 9. SPI Timing (TA = 25°C, VS = VDD I/O = 3.3 V)1  
Limit2, 3  
Parameter  
fSCLK  
tSCLK  
Min  
Max  
5
Unit  
MHz  
ns  
Description  
SPI clock frequency.  
1/(SPI clock frequency) mark-space ratio for the SCLK input is 40/60 to 60/40.  
CS falling edge to SCLK falling edge.  
200  
5
tDELAY  
ns  
tQUIET  
tDIS  
5
ns  
ns  
ns  
SCLK rising edge to CS rising edge.  
10  
CS rising edge to SDO disabled.  
tCS  
,DIS  
150  
CS deassertion between SPI communications.  
tS  
tM  
tSETUP  
tHOLD  
tSDO  
0.3 × tSCLK  
0.3 × tSCLK  
5
5
ns  
ns  
ns  
ns  
ns  
ns  
ns  
SCLK low pulse width (space).  
SCLK high pulse width (mark).  
SDI valid before SCLK rising edge.  
SDI valid after SCLK rising edge.  
SCLK falling edge to SDO/SDIO output transition.  
SDO/SDIO output high to output low transition.  
SDO/SDIO output low to output high transition.  
40  
20  
20  
4
tR  
4
tF  
1
CS  
The , SCLK, SDI, and SDO pins are not internally pulled up or down; they must be driven for proper operation.  
2 Limits based on characterization results, characterized with fSCLK = 5 MHz and bus load capacitance of 100 pF; not production tested.  
3 The timing values are measured corresponding to the input thresholds (VIL and VIH) given in Table 8.  
4 Output rise and fall times measured with capacitive load of 150 pF.  
Rev. 0 | Page 11 of 28  
 
 
 
ADXL313  
Data Sheet  
CS  
tDELAY  
tM  
tS  
tSCLK  
tQUIET  
tCS,DIS  
SCLK  
SDIO  
tSETUP  
tSDO  
tHOLD  
tR, tF  
R/W  
MB  
A5  
A0  
D7  
D0  
ADDRESS BITS  
DATA BITS  
SDO  
NOTES  
1. tSDO IS ONLY PRESENT DURING READS.  
Figure 17. SPI 3-Wire Read/Write  
CS  
tSCLK  
tM  
tS  
tCS,DIS  
tQUIET  
tDELAY  
SCLK  
tHOLD  
tSETUP  
R
MB  
A5  
A0  
X
X
SDI  
tSDO  
tDIS  
ADDRESS BITS  
X
X
X
X
D7  
D0  
SDO  
tR,  
tF  
DATA BITS  
Figure 18. SPI 4-Wire Read  
CS  
tM  
tS  
tSCLK  
tQUIET  
tCS,DIS  
tDELAY  
SCLK  
SDI  
tSETUP  
tHOLD  
MB  
W
A5  
A0  
D7  
D0  
tSDO  
tDIS  
ADDRESS BITS  
X
DATA BITS  
X
SDO  
X
X
X
X
tR  
,
tF  
Figure 19. SPI 4-Wire Write  
Rev. 0 | Page 12 of 28  
 
 
 
 
Data Sheet  
ADXL313  
V
DD I/O  
I2C  
With  
tied high to VDD I/O, the ADXL313 is in I2C mode,  
CS  
R
R
P
ADXL313  
PROCESSOR  
P
requiring a simple 2-wire connection, as shown in Figure 20.  
The ADXL313 conforms to the UM10204 I2C-Bus Specification  
and User Manual, Rev. 03—19 June 2007, available from NXP  
Semiconductor. It supports standard (100 kHz) and fast (400 kHz)  
data transfer modes if the bus parameters given in Table 10 and  
Table 11 are met. Single- or multiple-byte reads/writes are  
supported, as shown in Figure 21. With the ALT ADDRESS pin  
high, the 7-bit I2C address for the device is 0x1D, followed by the  
CS  
SDA  
ALT ADDRESS  
SCL  
D IN/OUT  
D OUT  
Figure 20. I2C Connection Diagram (Address 0x53)  
If other devices are connected to the same I2C bus, the nominal  
operating voltage level of these other devices cannot exceed VDD I/O  
by more than 0.3 V. External pull-up resistors, RP, are necessary  
for proper I2C operation. To ensure proper operation, refer to  
the UM10204 I2C-Bus Specification and User Manual, Rev. 03—  
19 June 2007, when selecting pull-up resistor values.  
W
R/ bit. This translates to 0x3A for a write and 0x3B for a read. An  
2
W
alternate I C address of 0x53 (followed by the R/ bit) can be  
chosen by grounding the ALT ADDRESS pin (Pin 23). This  
translates to 0xA6 for a write and 0xA7 for a read.  
Table 10. I2C Digital Input/Output  
Limit1  
Parameter  
Test Conditions/Comments  
Min  
Max  
Unit  
Digital Input  
Low Level Input Voltage (VIL)  
High Level Input Voltage (VIH)  
Low Level Input Current (IIL)  
High Level Input Current (IIH)  
Digital Output  
0.3 × VDD I/O  
0.1  
V
V
µA  
µA  
0.± × VDD I/O  
−0.1  
VIN = VDD I/O  
VIN = 0 V  
Low Level Output Voltage (VOL)  
VDD I/O < 2 V, IOL = 3 mA  
VDD I/O ≥ 2 V, IOL = 3 mA  
VOL = VOL, max  
0.2 × VDD I/O  
400  
V
mV  
mA  
pF  
Low Level Output Current (IOL)  
Pin Capacitance  
3
fIN = 1 MHz, VIN = 2.5 V  
8
1 Limits based on characterization results; not production tested.  
SINGLE-BYTE WRITE  
MASTER START  
SLAVE  
SLAVE ADDRESS + WRITE  
REGISTER ADDRESS  
REGISTER ADDRESS  
REGISTER ADDRESS  
REGISTER ADDRESS  
DATA  
STOP  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
MULTIPLE-BYTE WRITE  
MASTER START  
SLAVE  
SLAVE ADDRESS + WRITE  
DATA  
DATA  
STOP  
ACK  
ACK  
SINGLE-BYTE READ  
MASTER START  
SLAVE  
SLAVE ADDRESS + WRITE  
SLAVE ADDRESS + WRITE  
START1  
START1  
SLAVE ADDRESS + READ  
SLAVE ADDRESS + READ  
NACK  
ACK  
STOP  
ACK  
DATA  
DATA  
MULTIPLE-BYTE READ  
MASTER START  
SLAVE  
NACK  
STOP  
ACK  
DATA  
NOTES  
1. THIS START IS EITHER A RESTART OR A STOP FOLLOWED BY A START.  
2. THE SHADED AREAS REPRESENT WHEN THE DEVICE IS LISTENING.  
Figure 21. I2C Device Addressing  
Rev. 0 | Page 13 of 28  
 
 
 
 
 
 
 
 
ADXL313  
Data Sheet  
Table 11. I2C Timing (TA = 25°C, VS = VDD I/O = 3.3 V)  
Limit1, 2  
Parameter  
Min  
Max  
Unit  
kHz  
µs  
µs  
µs  
µs  
ns  
µs  
Description  
fSCL  
t1  
t2  
t3  
t4  
400  
SCL clock frequency  
SCL cycle time  
SCL high time  
SCL low time  
Start/repeated start condition hold time  
Data setup time  
2.5  
0.6  
1.3  
0.6  
100  
0
t5  
t6  
3, 4, 5, 6  
0.9  
Data hold time  
t±  
t8  
t9  
t10  
0.6  
0.6  
1.3  
µs  
µs  
µs  
ns  
ns  
ns  
ns  
ns  
Setup time for repeated start  
Stop condition setup time  
Bus-free time between a stop condition and a start condition  
Rise time of both SCL and SDA when receiving  
Rise time of both SCL and SDA when receiving or transmitting  
Fall time of SDA when receiving  
Fall time of both SCL and SDA when transmitting  
Fall time of both SCL and SDA when transmitting or receiving  
Capacitive load for each bus line  
300  
0
t11  
Cb  
250  
300  
±
20 + 0.1 Cb  
400  
pF  
1 Limits based on characterization results, with fSCL = 400 kHz and a 3 mA sink current; not production tested.  
2 All values referred to the VIH and the VIL levels given in Table 10.  
3 t6 is the data hold time that is measured from the falling edge of SCL. It applies to data in transmission and acknowledge.  
4 A transmitting device must internally provide an output hold time of at least 300 ns for the SDA signal (with respect to VIH, min of the SCL signal) to bridge the undefined  
region of the falling edge of SCL.  
5 The maximum t6 value must be met only if the device does not stretch the low period (t3) of the SCL signal.  
6 The maximum value for t6 is a function of the clock low time (t3), the clock rise time (t10), and the minimum data setup time (t5(min)). This value is calculated as  
t6(max) = t3 − t10 − t5(min)  
.
± Cb is the total capacitance of one bus line in picofarads.  
SDA  
t3  
t4  
t9  
t10  
t11  
SCL  
t2  
t7  
t1  
t8  
t4  
t6  
t5  
START  
CONDITION  
REPEATED  
START  
CONDITION  
STOP  
CONDITION  
Figure 22. I2C Timing Diagram  
Rev. 0 | Page 14 of 28  
 
Data Sheet  
ADXL313  
Activity  
INTERRUPTS  
The activity bit is set when acceleration greater than the value  
stored in the THRESH_ACT register (Address 0x24) is sensed.  
The ADXL313 provides two output pins for driving interrupts:  
INT1 and INT2. Both interrupt pins are push-pull, low impedance  
pins with output specifications shown in Table 12. The default  
configuration of the interrupt pins is active high. This can be  
changed to active low by setting the INT_INVERT bit in the  
DATA_FORMAT register (Address 0x31). All functions can be  
used simultaneously, with the only limiting feature being that  
some functions may need to share interrupt pins.  
Inactivity  
The inactivity bit is set when acceleration of less than the value  
stored in the THRESH_INACT register (Address 0x25) is sensed  
for more time than is specified in the TIME_INACT register  
(Address 0x26). The maximum value for TIME_INACT is 255 sec.  
Watermark  
Interrupts are enabled by setting the appropriate bit in the  
INT_ENABLE register (Address 0x2E) and are mapped to either  
the INT1 or INT2 pin based on the contents of the INT_MAP  
register (Address 0x2F). When initially configuring the interrupt  
pins, it is recommended that the functions and interrupt mapping  
be completed before enabling the interrupts. When changing the  
configuration of an interrupt, it is recommended that the interrupt  
be disabled first, by clearing the bit corresponding to that function  
in the INT_ENABLE register, and then the function be reconfig-  
ured before enabling the interrupt again. Configuration of the  
functions while the interrupts are disabled helps to prevent the  
accidental generation of an interrupt.  
The watermark bit is set when the number of samples in  
the FIFO equals the value stored in the samples bits in the  
FIFO_CTL register (Address 0x38). The watermark bit is  
cleared automatically when the FIFO is read, and the content  
returns to a value below the value stored in the samples bits.  
Overrun  
The overrun bit is set when new data replaces unread data. The  
precise operation of the overrun function depends on the FIFO  
mode. In bypass mode, the overrun bit is set when new data  
replaces unread data in the DATA_Xx, DATA_Yx, and DATA_Zx  
registers (Address 0x32 to Address 0x37). In all other modes, the  
overrun bit is set when the FIFO is filled. The overrun bit is  
automatically cleared when the contents of FIFO are read.  
The interrupt functions are latched and cleared either by reading  
the data registers (Address 0x32 to Address 0x37) until the inter-  
rupt condition is no longer valid for the data-related interrupts  
or by reading the INT_SOURCE register (Address 0x30) for the  
remaining interrupts. The following sections describe the  
interrupts that can be set in the INT_ENABLE register and  
monitored in the INT_SOURCE register.  
FIFO  
The ADXL313 contains patent pending technology for an  
embedded memory management system with a 32-level FIFO  
that can be used to minimize host processor burden. This buffer  
has four modes: bypass, FIFO, stream, and trigger (see Table 17).  
Each mode is selected by the settings of the FIFO_MODE bits  
in the FIFO_CTL register (Address 0x38).  
DATA_READY  
The DATA_READY bit is set when new data is available and is  
cleared when no new data is available.  
Bypass Mode  
In bypass mode, the FIFO is not operational and, therefore,  
remains empty.  
Table 12. Interrupt Pin Digital Output  
Limit1  
Parameter  
Test Conditions/Comments  
Min  
Max  
Unit  
Digital Output  
Low Level Output Voltage (VOL)  
High Level Output Voltage (VOH)  
Low Level Output Current (IOL)  
High Level Output Current (IOH)  
Pin Capacitance  
IOL = 300 µA  
IOH = −150 µA  
VOL = VOL, max  
VOH = VOH, min  
fIN = 1 MHz, VIN = 2.5 V  
0.2 × VDD I/O  
V
V
µA  
µA  
pF  
0.8 × VDD I/O  
300  
−150  
8
Rise/Fall Time  
Rise Time (tR)2  
Fall Time (tF)3  
CLOAD = 150 pF  
CLOAD = 150 pF  
210  
150  
ns  
ns  
1 Limits based on characterization results, not production tested.  
2 Rise time is measured as the transition time from VOL, max to VOH, min of the INTx pin.  
3 Fall time is measured as the transition time from VOH, min to VOL, max of the INTx pin.  
Rev. 0 | Page 15 of 28  
 
 
 
ADXL313  
Data Sheet  
FIFO Mode  
If a single-byte read operation is performed, the remaining  
bytes of data for the current FIFO sample are lost. Therefore, all  
axes of interest must be read in a burst (or multiple-byte) read  
operation. To ensure that the FIFO has completely popped (that  
is, that new data has completely moved into the DATA_Xx,  
DATA_Yx, and DATA_Zx registers), there must be at least 5 μs  
between the end of reading the data registers and the start of a  
new read of the FIFO or a read of the FIFO_STATUS register  
(Address 0x39). The end of reading a data register is signified by  
In FIFO mode, data from measurements of the x-, y-, and z-axes  
are stored in the FIFO. When the number of samples in the FIFO  
equals the level specified in the samples bits of the FIFO_CTL  
register (Address 0x38), the watermark interrupt is set. The  
FIFO continues accumulating samples until it is full (32 samples  
from measurements of the x-, y-, and z-axes) and then stops  
collecting data. After the FIFO stops collecting data, the device  
continues to operate; therefore, features such as activity detection  
can be used after the FIFO is full. The watermark interrupt contin-  
ues to occur until the number of samples in the FIFO is less  
than the value stored in the samples bits of the FIFO_CTL  
register.  
CS  
the transition from Register 0x37 to Register 0x38 or by the pin  
going high.  
For SPI operation at 1.6 MHz or less, the register addressing  
portion of the transmission is a sufficient delay to ensure that  
the FIFO has completely popped. For SPI operation greater than  
Stream Mode  
CS  
1.6 MHz, it is necessary to deassert the  
pin to ensure a total  
In stream mode, data from measurements of the x-, y-, and z-  
axes is stored in FIFO. When the number of samples in the FIFO  
equals the level specified in the samples bits of the FIFO_CTL  
register (Address 0x38), the watermark interrupt is set. FIFO  
continues accumulating samples and holds the latest 32 samples  
from measurements of the x-, y-, and z-axes, discarding older  
data as new data arrives. The watermark interrupt continues  
occurring until the number of samples in FIFO is less than the  
value stored in the samples bits of the FIFO_CTL register.  
delay of 5 μs; otherwise, the delay is not sufficient. The total delay  
necessary for 5 MHz operation is at most 3.4 μs. This is not a  
concern when using I2C mode because the communication rate is  
low enough to ensure a sufficient delay between FIFO reads.  
SELF TEST  
The ADXL313 incorporates a self test feature that effectively  
tests its mechanical and electronic systems simultaneously.  
When the self test function is enabled (via the SELF_TEST bit  
in the DATA_FORMAT register, Address 0x31), an electrostatic  
force is exerted on the mechanical sensor. This electrostatic force  
moves the mechanical sensing element in the same manner as  
acceleration, and it is additive to the acceleration experienced  
by the device. This added electrostatic force results in an output  
change in the x-, y-, and z-axes. Because the electrostatic force  
Trigger Mode  
In trigger mode, the FIFO accumulates samples, holding the  
latest 32 samples from measurements of the x-, y-, and z-axes.  
After a trigger event occurs and an interrupt is sent to the INT1  
or INT2 pin (determined by the trigger bit in the FIFO_CTL  
register), FIFO keeps the last n samples (where n is the value  
specified by the samples bits in the FIFO_CTL register) and  
then operates in FIFO mode, collecting new samples only when  
the FIFO is not full. A delay of at least 5 μs must be present between  
the trigger event occurring and the start of reading data from  
the FIFO to allow the FIFO to discard and retain the necessary  
samples. Additional trigger events cannot be recognized until  
the trigger mode is reset. To reset the trigger mode, set the device  
to bypass mode and then set the device back to trigger mode. Note  
that the FIFO data must be read first because placing the device  
into bypass mode clears FIFO.  
2
is proportional to VS , the output change varies with VS. The self  
test feature of the ADXL313 also exhibits a bimodal behavior.  
However, the limits shown in Table 1 and Table 13 are valid for  
all potential self test values across the entire allowable voltage  
range. Use of the self test feature at data rates of less than 100 Hz or  
at 1600 Hz may yield values outside these limits. Therefore, the  
part must be in normal power operation (LOW_POWER bit = 0  
in the BW_RATE register, Address 0x2C) and be placed into a  
data rate of 100 Hz through 800 Hz or 3200 Hz for the self test  
function to operate correctly.  
Retrieving Data from FIFO  
Table 13. Self Test Output (TA = 25°C, 2.0 V ≤ VS ≤ 3.6 V)  
Axis  
Min (g)  
Max (g)  
The FIFO data is read through the DATA_Xx, DATA_Yx, and  
DATA_Zx registers (Address 0x32 to Address 0x37). When the  
FIFO is in FIFO, stream, or trigger mode, reads to the DATA_Xx,  
DATA_xY, and DATA_Zx registers read data stored in the  
FIFO. Each time data is read from the FIFO, the oldest x-, y-,  
and z-axes data is placed into the DATA_Xx, DATA_Yx, and  
DATA_Zx registers.  
X
Y
Z
0.20  
−2.36  
0.30  
2.36  
+0.20  
3.±0  
Rev. 0 | Page 16 of 28  
 
 
 
Data Sheet  
ADXL313  
REGISTER MAP  
Table 14. Register Map  
Reset  
Value  
Reg  
Name  
Type D7  
D6  
D5  
D4  
D3  
DEVID_0[±:0]  
DEVID_1[±:0]  
PARTID[±:0]  
REVID[±:0]  
XID[±:0]  
D2  
D1  
D0  
0x00  
0x01  
0x02  
0x03  
0x04  
DEVID_0  
DEVID_1  
PARTID  
REVID  
R
0xAD  
0x1D  
0xDC  
0x00  
0x00  
R
R
R
XID  
R
0x05 to  
0x1±  
Reserved  
RSVD  
Reserved  
0x18  
SOFT_RESET  
Reserved  
W
SOFT_RESET[±:0]  
Reserved  
0x00  
R/  
0x19 to  
0x1D  
RSVD  
0x1E  
0x1F  
0x20  
OFSX  
W
W
W
OFSX[±:0]  
OFSY[±:0]  
OFSZ[±:0]  
Reserved  
0x00  
0x00  
0x00  
R/  
R/  
R/  
OFSY  
OFSZ  
0x21 to  
0x23  
Reserved  
RSVD  
0x24  
0x25  
0x26  
0x2±  
THRESH_ACT  
THRESH_INACT  
TIME_INACT  
W
W
W
W
THRESH_ACT[±:0]  
THRESH_INACT[±:0]  
TIME_INACT[±:0]  
0x00  
0x00  
0x00  
R/  
R/  
R/  
R/  
ACT_INACT_CTL  
ACT_  
AC/DC  
ACT_X  
0
ACT_Y  
ACT_Z  
INACT_  
AC/DC  
INACT_X INACT_Y  
Rate[3:0]  
INACT_Z 0x00  
0x28 to  
0x2B  
Reserved  
RSVD  
Reserved  
0x2C  
0x2D  
BW_RATE  
W
W
0
0
0
LOW_POWER  
AUTO_SLEEP  
0x0A  
0x00  
R/  
POWER_CTL  
I2C_  
DISABLE  
Link  
Measure  
Inactivity  
Inactivity  
Inactivity  
Sleep  
Wake-up[1:0]  
R/  
0x2E  
0x2F  
0x30  
0x31  
INT_ENABLE  
INT_MAP  
W
R/  
W
R/  
R
DATA_  
READY  
0
0
0
0
Activity  
Activity  
Activity  
0
0
0
0
Watermark Overrun  
0x00  
0x00  
0x02  
0x00  
DATA_  
READY  
0
Watermark Overrun  
Watermark Overrun  
Range[1:0]  
INT_SOURCE  
DATA_FORMAT  
DATA_  
READY  
0
W
R/  
SELF_  
TEST  
SPI  
INT_  
INVERT  
FULL_RES Justify  
0x32  
0x33  
0x34  
0x35  
0x36  
0x3±  
0x38  
0x39  
DATA_X0  
DATA_X1  
DATA_Y0  
DATA_Y1  
DATA_Z0  
DATA_Z1  
FIFO_CTL  
FIFO_STATUS  
R
R
R
R
R
R
R/  
R
DATA_X0[±:0]  
0x00  
0x00  
0x00  
0x00  
0x00  
0x00  
0x00  
0x00  
DATA_X1[±:0]  
DATA_Y0[±:0]  
DATA_Y1[±:0]  
DATA_Z0[±:0]  
DATA_Z1[±:0]  
W
FIFO_MODE[1:0]  
Trigger  
Samples[4:0]  
Entries  
FIFO_TRIG  
0
Rev. 0 | Page 1± of 28  
 
ADXL313  
Data Sheet  
The OFSX, OFSY, and OFSZ registers are each eight bits and  
offer user-set offset adjustments in twos complement format  
with a scale factor of 3.9 mg/LSB (that is, 0x7F = 0.5 g). The  
value stored in the offset registers is automatically added to the  
acceleration data, and the resulting value is stored in the output  
data registers.  
REGISTER DEFINITIONS  
Register 0x00—DEVID_0 (Read Only)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
1
0
1
0
1
1
0
1
The DEVID_0 register holds a fixed device ID identifying  
Analog Devices, Inc., as the device manufacturer. The default  
value of this register is 0xAD.  
Register 0x24—THRESH_ACT (Read/Write)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
Register 0x01—DEVID_1 (Read Only)  
THRESH_ACT[±:0]  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
The THRESH_ACT register is eight bits and holds the threshold  
value for detecting activity. The data format is unsigned;  
therefore, the magnitude of the activity event is compared with  
the value in the THRESH_ACT register. The scale factor is  
15.625 mg/LSB. A value of 0 may result in undesirable behavior  
if the activity interrupt is enabled.  
0
0
0
1
1
1
0
1
The DEVID_1 register holds a fixed device ID that further  
enhances traceability of the ADXL313. The default value of this  
register is 0x1D.  
Register 0x02—PARTID (Read Only)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
Register 0x25—THRESH_INACT (Read/Write)  
1
1
0
0
1
0
1
1
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
THRESH_INACT[±:0]  
The PARTID register identifies the device as an ADXL313. The  
default hexadecimal value stored in this register, 0xDC, is meant  
to be interpreted as an octal value that corresponds to 313. If  
the user does not read back 0xDC from this register, assume  
that the device under test is not an ADXL313 device.  
The THRESH_INACT register is eight bits and holds the threshold  
value for detecting inactivity. The data format is unsigned;  
therefore, the magnitude of the inactivity event is compared  
with the value in the THRESH_INACT register. The scale factor is  
15.625 mg/LSB. A value of 0 may result in undesirable behavior  
if the inactivity interrupt is enabled.  
Register 0x03—REVID (Read Only)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
REVID[±:0]  
Register 0x26—TIME_INACT (Read/Write)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
The number contained in the REVID register represents the  
silicon revision of the ADXL313. This number is incremented  
for any major silicon revision.  
TIME_INACT[±:0]  
The TIME_INACT register is eight bits and contains an unsigned  
time value. Acceleration must be less than the value in the  
THRESH_INACT register for the amount of time represented by  
TIME_INACT for inactivity to be declared. The scale factor is  
1 sec/LSB. Unlike the other interrupt functions, which use  
unfiltered data (see the Threshold section), the inactivity  
function uses filtered output data. At least one output sample  
must be generated for the inactivity interrupt to be triggered.  
This results in the function appearing unresponsive if the  
TIME_INACT register is set to a value less than the time  
constant of the output data rate. A value of 0 results in an  
interrupt when the output data is less than the value in the  
THRESH_INACT register.  
Register 0x04—XID (Read Only)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
XID[±:0]  
The XID register stores a semi-unique serial number that is  
generated from the device trim and calibration process.  
Register 0x18—SOFT_RESET (Read/Write)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
SOFT_RESET[±:0]  
Writing a value of 0x52 to Register 0x18 triggers the soft reset  
function of the ADXL313. The soft reset returns the ADXL313  
to the beginning of its power-on initialization routine, clearing  
the configuration settings that were written to the memory  
map, which allows easy reconfiguration of the ADXL313 device.  
Register 0x27—ACT_INACT_CTL (Read/Write)  
D7  
D6  
D5  
D4  
ACT_AC/DC  
ACT_X  
D2  
ACT_Y  
D1  
ACT_Z  
D0  
Register 0x1E—OFSX (Read/Write),  
Register 0x1F—OFSY (Read/Write),  
Register 0x20—OFSZ (Read/Write)  
D3  
INACT_AC/DC INACT_X  
INACT_Y  
INACT_Z  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
ACT_AC/DC and INACT_AC/DC Bits  
OFSX[±:0]  
OFSY[±:0]  
OFSZ[±:0]  
A setting of 0 selects dc-coupled operation, and a setting of 1  
enables ac-coupled operation. In dc-coupled operation, the  
current acceleration magnitude is compared directly with  
THRESH_ACT and THRESH_INACT to determine whether  
activity or inactivity is detected.  
Rev. 0 | Page 18 of 28  
 
 
 
 
 
 
 
 
Data Sheet  
ADXL313  
In ac-coupled operation for activity detection, the acceleration  
value at the start of activity detection is taken as a reference  
value. New samples of acceleration are then compared to this  
reference value and, if the magnitude of the difference exceeds  
the THRESH_ACT value, the device triggers an activity interrupt.  
not interpret SPI commands as an I2C start condition, assert the  
I2C_Disable bit.  
Link Bit  
A setting of 1 in the link bit with both the activity and inactivity  
functions enabled delays the start of the activity function until  
inactivity is detected. After activity is detected, inactivity detection  
begins, preventing the detection of activity. This bit serially links  
the activity and inactivity functions. When this bit is set to 0,  
the inactivity and activity functions are concurrent. Additional  
information can be found in the Link Mode section.  
Similarly, in ac-coupled operation for inactivity detection, a  
reference value is used for comparison and is updated whenever  
the device exceeds the inactivity threshold. After the reference  
value is selected, the device compares the magnitude of the  
difference between the reference value and the current acceleration  
with THRESH_INACT. If the difference is less than the value in  
THRESH_INACT for the time in TIME_INACT, the device is  
considered inactive and the inactivity interrupt is triggered.  
When clearing the link bit, it is recommended that the part be  
placed into standby mode and then set back to measurement  
mode with a subsequent write. This is done to ensure that the  
device is properly biased if sleep mode is manually disabled;  
otherwise, the first few samples of data after the link bit is cleared  
may have additional noise, especially if the device was asleep  
when the bit was cleared.  
ACT_x and INACT_x Bits  
A setting of 1 enables x-, y-, or z-axis participation in detecting  
activity or inactivity. A setting of 0 excludes the selected axis  
from participation. If all axes are excluded, the function is  
disabled. For activity detection, all participating axes are  
logically ORed, causing the activity function to trigger when  
any of the participating axes exceeds the threshold. For inactiv-  
ity detection, all participating axes are logically ANDed, causing  
the inactivity function to trigger only if all participating axes are  
below the threshold for the specified period of time.  
AUTO_SLEEP Bit  
If the link bit is set, a setting of 1 in the AUTO_SLEEP bit sets  
the ADXL313 to switch to sleep mode when inactivity is detected  
(that is, when acceleration is below the THRESH_INACT value for  
at least the time indicated by TIME_INACT). A setting of 0  
disables automatic switching to sleep mode. See the description of  
the sleep bit in the Sleep Bit section for more information.  
Register 0x2C—BW_RATE (Read/Write)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
Rate  
D0  
When clearing the AUTO_SLEEP bit, it is recommended that the  
part be placed into standby mode and then set back to measure-  
ment mode with a subsequent write. This is done to ensure that  
the device is properly biased if sleep mode is manually disabled;  
otherwise, the first few samples of data after the AUTO_SLEEP  
bit is cleared may have additional noise, especially if the device  
was asleep when the bit was cleared.  
0
0
0
LOW_POWER  
LOW_POWER Bit  
A setting of 0 in the LOW_POWER bit selects normal operation,  
and a setting of 1 selects reduced power operation, which has  
somewhat higher noise (see the Power Modes section for details).  
Rate Bits  
Measure Bit  
These bits select the device bandwidth and output data rate (see  
Table 5 and Table 6 for details). The default value is 0x0A, which  
translates to a 100 Hz output data rate. Select an output data  
rate that is appropriate for the communication protocol and  
frequency selected. Selecting too high of an output data rate  
with a low communication speed results in samples being  
discarded.  
A setting of 0 in the measure bit places the part into standby mode,  
and a setting of 1 places the part into measurement mode. The  
ADXL313 powers up in standby mode with minimum power  
consumption.  
Sleep Bit  
A setting of 0 in the sleep bit puts the part into the normal mode  
of operation, and a setting of 1 places the part into sleep mode.  
Sleep mode suppresses DATA_READY (see Register 0x2E,  
Register 0x2F, and Register 0x30), stops transmission of data to the  
FIFO, and switches the sampling rate to one specified by the  
wake-up bits. In sleep mode, only the activity function can be used.  
Register 0x2D—POWER_CTL (Read/Write)  
D7  
D6  
D5  
D4  
0
I2C_DISABLE  
D2  
Link  
D1  
AUTO_SLEEP  
D3  
D0  
Measure  
Sleep  
Wake-up  
When clearing the sleep bit, it is recommended that the part be  
placed into standby mode and then set back to measurement  
mode with a subsequent write. This is done to ensure that the  
device is properly biased if sleep mode is manually disabled;  
otherwise, the first few samples of data after the sleep bit is  
cleared may have additional noise, especially if the device was  
asleep when the bit was cleared.  
I2C_Disable Bit  
The ADXL313 is capable of communicating via SPI or I2C  
transmission protocols. Typically, these protocols do not  
overlap; however, situations may arise where SPI transactions  
can imitate an I2C start command. This causes the ADXL313 to  
respond unexpectedly, causing a communications issue with  
other devices on the network. To ensure that the ADXL313 does  
Rev. 0 | Page 19 of 28  
 
ADXL313  
Data Sheet  
Wake-Up Bits  
Register 0x31—DATA_FORMAT (Read/Write)  
D7  
D6 D5  
D4 D3  
D2  
D1 D0  
These bits control the frequency of readings in sleep mode as  
described in Table 15.  
SELF_TEST SPI INT_INVERT  
0
FULL_RES Justify  
Range  
The DATA_FORMAT register controls the presentation of data  
to Register 0x32 through Register 0x37. All data, except that for  
the 4 g range, must be clipped to avoid rollover.  
Table 15. Frequency of Readings in Sleep Mode  
Setting  
D1  
0
0
1
1
D0  
0
1
0
1
Frequency (Hz)  
SELF_TEST Bit  
8
4
2
1
A setting of 1 in the SELF_TEST bit applies a self test force to  
the sensor, causing a shift in the output data. A value of 0 disables  
the self test force.  
SPI Bit  
Register 0x2E—INT_ENABLE (Read/Write)  
D7  
D6  
D5  
D4  
A value of 1 in the SPI bit sets the device to 3-wire SPI mode,  
and a value of 0 sets the device to 4-wire SPI mode.  
DATA_READY  
D3  
0
0
Activity  
D0  
D2  
0
D1  
INT_INVERT Bit  
Inactivity  
Watermark  
Overrun  
A value of 0 in the INT_INVERT bit sets the interrupts to active  
high, and a value of 1 sets the interrupts to active low.  
Setting bits in this register to a value of 1 enables their respective  
functions to generate interrupts, whereas a value of 0 prevents  
the functions from generating interrupts. The DATA_READY,  
watermark, and overrun bits enable only the interrupt output;  
the functions are always enabled. It is recommended that interrupts  
be configured before enabling their outputs.  
FULL_RES Bit  
When this bit is set to a value of 1, the device is in full resolution  
mode, where the output resolution increases with the g range  
set by the range bits to maintain 1024 LSB/g sensitivity. When  
the FULL_RES bit is set to 0, the device is in 10-bit mode, and  
the range bits determine the maximum g range and scale factor.  
Register 0x2F—INT_MAP (Read/Write)  
D7  
D6  
D5  
D4  
DATA_READY  
D3  
0
0
Activity  
D0  
Justify Bit  
D2  
0
D1  
A setting of 1 in the justify bit selects left (MSB) justified mode,  
and a setting of 0 selects right justified (LSB) mode with sign  
extension.  
Inactivity  
Watermark  
Overrun  
Any bits set to 0 in this register send their respective interrupts to  
the INT1 pin, whereas bits set to 1 send their respective interrupts  
to the INT2 pin. All selected interrupts for a given pin are ORed.  
Range Bits  
These bits set the g range as described in Table 16.  
Register 0x30—INT_SOURCE (Read Only)  
D7  
Table 16. g Range Setting  
D6  
D5  
D4  
Setting  
DATA_READY  
D3  
0
0
Activity  
D0  
D1  
0
D0  
0
Range (g)  
±0.5  
±1  
±2  
±4  
D2  
0
D1  
Inactivity  
Watermark  
Overrun  
0
1
1
1
0
1
Bits set to 1 in this register indicate that their respective functions  
have triggered an event, whereas a value of 0 indicates that the  
corresponding event has not occurred. The DATA_READY,  
watermark, and overrun bits are always set if the corresponding  
events occur, regardless of the INT_ENABLE register settings,  
and are cleared by reading data from the DATA_Xx, DATA_Yx,  
and DATA_Zx registers. The DATA_READY and watermark  
bits may require multiple reads, as indicated in the FIFO mode  
descriptions in the FIFO section. Other bits, and the corresponding  
interrupts, are cleared by reading the INT_SOURCE register.  
Rev. 0 | Page 20 of 28  
 
 
 
 
 
Data Sheet  
ADXL313  
Register 0x32 and Register 0x33—DATA_X0, DATA_X1  
(Read Only),  
Register 0x34 and Register 0x35—DATA_Y0, DATA_Y1  
(Read Only),  
Trigger Bit  
A value of 0 in the trigger bit links the trigger event to INT1,  
and a value of 1 links the trigger event to INT2.  
Register 0x36 and Register 0x37—DATA_Z0, DATA_Z1  
(Read Only)  
Samples Bits  
The function of these bits depends on the FIFO mode selected  
(see Table 18). Entering a value of 0 in the samples bits immedi-  
ately sets the watermark status bit in the INT_SOURCE register,  
regardless of which FIFO mode is selected. Undesirable opera-  
tion may occur if a value of 0 is used for the samples bits when  
trigger mode is used.  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
DATA_X0[±:0]  
DATA_X1[±:0]  
DATA_Y0[±:0]  
DATA_Y1[±:0]  
DATA_Z0[±:0]  
DATA_Z1[±:0]  
Table 18. Samples Bits Functions  
FIFO Mode Samples Bits Function  
These six bytes (Register 0x32 to Register 0x37) are eight bits  
each and hold the output data for each axis. Register 0x32 and  
Register 0x33 hold the output data for the x-axis, Register 0x34 and  
Register 0x35 hold the output data for the y-axis, and Register 0x36  
and Register 0x37 hold the output data for the z-axis.  
Bypass  
FIFO  
None.  
Specifies how many FIFO entries are needed to  
trigger a watermark interrupt.  
Stream  
Trigger  
Specifies how many FIFO entries are needed to  
trigger a watermark interrupt.  
Specifies how many FIFO samples are retained in  
the FIFO buffer before a trigger event.  
The output data is twos complement, with DATA_x0 as the least  
significant byte and DATA_x1 as the most significant byte, where x  
represent X, Y, or Z. The DATA_FORMAT register (Address 0x31)  
controls the format of the data. It is recommended that a multiple-  
byte read of all registers be performed to prevent a change in  
data between reads of sequential registers.  
0x39—FIFO_STATUS (Read Only)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
FIFO_TRIG  
0
Entries  
FIFO_TRIG Bit  
Register 0x38—FIFO_CTL (Read/Write)  
A 1 in the FIFO_TRIG bit corresponds to a trigger event occurring,  
and a 0 means that a FIFO trigger event has not occurred.  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
FIFO_MODE  
Trigger  
Samples  
Entries Bits  
FIFO_MODE Bits  
These bits report how many data values are stored in the FIFO.  
Access to collect the data from the FIFO is provided through  
the DATA_Xx, DATA_Yx, and DATA_Zx registers. FIFO reads  
must be done in burst or multiple-byte mode because each FIFO  
level is cleared after any read (single- or multiple-byte) of the  
FIFO. The FIFO stores a maximum of 32 entries, which equates  
to a maximum of 33 entries available at any given time because  
an additional entry is available at the output filter of the device.  
These bits set the FIFO mode, as described in Table 17.  
Table 17. FIFO Modes  
Setting  
D7 D6 Mode  
Function  
Bypass FIFO is bypassed.  
FIFO  
FIFO collects up to 32 values and then  
0
0
0
1
stops collecting data, collecting new data  
only when FIFO is not full.  
1
1
0
1
Stream FIFO holds the last 32 data values. When  
FIFO is full, the oldest data is overwritten  
with newer data.  
Trigger When triggered by the trigger bit, FIFO  
holds the last data samples before the  
trigger event and then continues to collect  
data until full. New data is collected only  
when FIFO is not full.  
Rev. 0 | Page 21 of 28  
 
 
ADXL313  
Data Sheet  
APPLICATIONS INFORMATION  
POWER SUPPLY DECOUPLING  
THRESHOLD  
The lower output data rates are achieved by decimating a  
common sampling frequency inside the device. The activity  
detection function is performed using undecimated data.  
Because the bandwidth of the output data varies with the data  
rate and is lower than the bandwidth of the undecimated data,  
the high frequency and high g data that are used to determine  
activity may not be present if the output of the accelerometer is  
examined. This may result in functions triggering when accelera-  
tion data does not appear to meet the conditions set by the user  
for the corresponding function.  
A 1 μF tantalum capacitor (CS) at VS and a 0.1 μF ceramic capacitor  
(CI/O) at VDD I/O placed close to the ADXL313 supply pins is  
recommended to adequately decouple the accelerometer from  
noise on the power supply. If additional decoupling is necessary,  
a resistor or ferrite bead, no larger than 100 Ω, in series with VS  
may be helpful. Additionally, increasing the bypass capacitance  
on VS to a 10 μF tantalum capacitor in parallel with a 0.1 μF  
ceramic capacitor may also improve noise.  
Take care to ensure that the connection from the ADXL313  
ground to the power supply ground has low impedance because  
noise transmitted through ground has an effect similar to noise  
transmitted through VS. It is recommended that VS and VDD I/O  
be separate supplies to minimize digital clocking noise on the  
VS supply. If this is not possible, additional filtering of the  
supplies as previously mentioned may be necessary.  
LINK MODE  
The function of the link bit in the POWER_CTL register  
(Address 0x2D) is to reduce the number of activity interrupts  
that the processor must service by setting the device to look  
for activity only after inactivity. For proper operation of this  
feature, the processor must still respond to the activity and  
inactivity interrupts by reading the INT_SOURCE register  
(Address 0x30) and, therefore, clearing the interrupts. If an activity  
interrupt is not cleared, the part cannot go into autosleep mode.  
V
V
S
DD I/O  
C
C
I/O  
S
V
V
S
DD I/O  
ADXL313  
SLEEP MODE vs. LOW POWER MODE  
SDA/SDI/SDIO  
3-WIRE OR  
4-WIRE SPI  
OR I C  
SDO/ALT ADDRESS  
SCL/SCLK  
INT1  
INT2  
INTERRUPT  
CONTROL  
In applications where a low data rate and low power consumption  
are desired (at the expense of noise performance), it is recom-  
mended that low power mode be used. The use of low power  
mode preserves the functionality of the DATA_READY  
interrupt and the FIFO for postprocessing of the acceleration  
data. Sleep mode, while offering a low data rate and low power  
consumption, is not intended for data acquisition.  
2
INTERFACE  
CS  
GND  
Figure 23. Application Diagram  
MECHANICAL CONSIDERATIONS FOR MOUNTING  
Mount the ADXL313 on the PCB in a location close to a hard  
mounting point of the PCB to the case. Mounting the ADXL313  
at an unsupported PCB location, as shown in Figure 24, may  
result in large, apparent measurement errors due to undamped  
PCB vibration. Placing the accelerometer near a hard mounting  
point ensures that any PCB vibration at the accelerometer is above  
the accelerometers mechanical sensor resonant frequency and,  
therefore, effectively invisible to the accelerometer. Multiple  
mounting points close to the sensor and/or a thicker PCB also  
help to reduce the effect of system resonance on the performance  
of the sensor.  
However, when sleep mode is used in conjunction with the  
autosleep mode and the link mode, the part can automatically  
switch to a low power, low sampling rate mode when inactivity  
is detected. To prevent the generation of redundant inactivity  
interrupts, the inactivity interrupt is automatically disabled and  
activity is enabled. When the ADXL313 is in sleep mode, the host  
processor can also be placed into sleep mode or low power  
mode to save significant system power. When activity is  
detected, the accelerometer automatically switches back to the  
original data rate of the application and provides an activity  
interrupt that can be used to wake up the host processor.  
Similar to when inactivity occurs, detection of activity events is  
disabled and inactivity is enabled.  
ACCELEROMETERS  
PCB  
MOUNTING POINTS  
Figure 24. Incorrectly Placed Accelerometers  
Rev. 0 | Page 22 of 28  
 
 
 
 
 
 
 
Data Sheet  
ADXL313  
Next, enable self test by setting Bit D7 of the DATA_FORMAT  
register (Address 0x31). The output needs some time (about  
four samples) to settle after enabling self test. After allowing the  
output to settle, take several samples of the x-, y-, and z-axis  
acceleration data, and average them. It is recommended that the  
same number of samples be taken for this average as was previously  
taken. Store and label these averaged values appropriately as the  
USING SELF TEST  
The self test change is defined as the difference between the  
acceleration output of an axis with self test enabled and the  
acceleration output of the same axis with self test disabled (see  
Endnote 4 of Table 1). This definition assumes that the sensor  
does not move between these two measurements because, if the  
sensor moves, a nonself test related shift corrupts the test.  
value with self test enabled, that is, XST_ON, YST_ON, and ZST_ON  
.
Proper configuration of the ADXL313 is also necessary for an  
accurate self test measurement. Set the part with a data rate  
greater than or equal to 100 Hz. This is done by ensuring that a  
value greater than or equal to 0x0A is written into the rate bits  
(Bit D3 through Bit D0) in the BW_RATE register (Address 0x2C).  
The part must also be placed into normal power operation by  
ensuring that the LOW_POWER bit in the BW_RATE register  
is cleared (LOW_POWER bit = 0) for accurate self test measure-  
ments. It is recommended that the part be set to full resolution,  
4 g mode to ensure that there is sufficient dynamic range for  
the entire self test shift. This is done by setting Bit D3 of the  
DATA_FORMAT register (Address 0x31) and writing a value of  
0x03 to the range bits (Bit D1 and Bit D0) of the DATA_FORMAT  
register. This results in a high dynamic range for measurement  
and 1024 LSB/g sensitivity.  
Self test can then be disabled by clearing Bit D7 of the DATA_  
FORMAT register (Address 0x31).  
With the stored values for self test enabled and disabled, the self  
test change is as follows:  
X
ST = XST_ON XST_OFF  
ST = YST_ON YST_OFF  
Y
Z
ST = ZST_ON ZST_OFF  
Because the measured output for each axis is expressed in LSBs,  
XST, YST, and ZST are also expressed in LSBs. These values can be  
converted to acceleration (g) by multiplying each value by the  
sensitivity, 1024 LSB/g, when configured for full resolution  
mode. When operating in 10-bit mode, the self test delta in  
LSBs varies according to the selected g range, even though the  
self test force, in g, remains unchanged. Using a range below  
4 g may result in insufficient dynamic range and should be  
considered when selecting the range of operation for measuring  
self test.  
After the part is configured for accurate self test measurement,  
several samples of x-, y-, and z-axis acceleration data should be  
retrieved from the sensor and averaged together. The number of  
samples averaged is a choice of the system designer, but a recom-  
mended starting point is 0.1 sec worth of data, which corresponds  
to 10 samples at 100 Hz data rate. Store and label the averaged  
If the self test change is within the valid range, the test is considered  
successful. Generally, a part is considered to pass if the minimum  
magnitude of change is achieved. However, a part that changes  
by more than the maximum magnitude is not necessarily a failure.  
values appropriately as the self test disabled data, that is, XST_OFF  
,
YST_OFF, and ZST_OFF  
.
Rev. 0 | Page 23 of 28  
 
ADXL313  
Data Sheet  
3200 HZ AND 1600 HZ ODR DATA FORMATTING  
Table 19. Conditions for Which the LSB Is Set to 0 (3200 Hz  
and 1600 Hz Output Data Rates Only)  
The following section applies for 3200 Hz and 1600 Hz output  
data rates only. This section can be ignored for all other data rates.  
Justify  
(0x31[2])  
FULL_RES  
(0x31[3])  
Range  
(g)  
LSB Bit Position  
For 3200 Hz and 1600 Hz output data rates, when the ADXL313  
is configured for either a 0.5 g output range or the full resolution  
mode is enabled, the LSB of the output data-word is always 0.  
If the acceleration data-word is right justified, this corresponds  
to Bit D0 of the DATA_x0 register, as shown in Figure 25 and  
Table 19.  
0
0
0
0
1
1
1
1
0 or 1  
1
1
1
±0.5  
±1  
±2  
±4  
±0.5  
±1  
D0  
D0  
D0  
D0  
D6  
D5  
D4  
D3  
0 or 1  
1
1
1
When data is left justified and the part is operating in 0.5 g  
mode, the LSB of the output data-word is Bit D6 of the DATAx0  
register. In full resolution operation, the location of the LSB  
changes according to the selected output range. Table 19 and  
Figure 26 demonstrate how the position of the LSB changes  
when full resolution mode is enabled.  
±2  
±4  
The use of 3200 Hz and 1600 Hz output data rates for fixed 10-bit  
operation in the 1 g, 2 g, and 4 g output ranges provides an  
LSB that is valid and that changes according to the applied accel-  
eration. Therefore, in these modes of operation, Bit D0 is not  
always 0 when output data is right justified, and Bit D6 is not  
always 0 when output data is left justified.  
DATA_x1 REGISTER  
DATA_x0 REGISTER  
D7 D6 D5 D4 D3 D2 D1 D0  
D7 D6 D5 D4 D3 D2 D1 D0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
0
FOR THE RIGHT JUSTIFIED DATA:  
WHEN OPERATING THE ADXL313 WITH AN OUTPUT RATE OF EITHER 3200Hz OR 1600Hz, THE D0 BIT OF  
THE DATA_x0 REGISTER IS ALWAYS 0 UNDER EITHER OF THE FOLLOWING CONDITIONS:  
1) FULL RESOLUTION MODE IS ENABLED (ANY g RANGE), OR  
2) DEVICE RANGE IS SET TO ±0.5g  
Figure 25. Right Justified Data Formatting: 3200 Hz and 1600 Hz Output Data Rate  
DATA_x1 REGISTER  
DATA_x0 REGISTER  
D7 D6 D5 D4 D3 D2 D1 D0  
D7 D6 D5 D4 D3 D2 D1 D0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
FULL RESOLUTION AND 10-BIT MODE: LSB FOR ±0.5 RANGE = 0  
FULL RESOLUTION MODE; LSB FOR ±1g RANGE = 0  
FULL RESOLUTION MODE; LSB FOR ±2g RANGE = 0  
FULL RESOLUTION MODE; LSB FOR ±4g RANGE = 0  
FOR THE LEFT JUSTIFIED DATA:  
WHEN OPERATING THE ADXL313 WITH AN OUTPUT RATE OF EITHER 3200Hz OR 1600Hz, THE LSB OF THE  
ACCELERATION DATA-WORD IS ALWAYS 0 UNDER THE FOLLOWING CONDITIONS:  
1) FULL RESOLUTION MODE IS ENABLED (ANY g RANGE), OR  
2) DEVICE RANGE IS SET TO ±0.5g.  
FULL RESOLUTION MODE CAUSES THE LOCATION OF THE LSB TO CHANGE ACCORDING TO  
THE SELECTED g RANGE. ALTHOUGH ITS LOCATION MAY CHANGE, ITS VALUE WILL REMAIN 0.  
Figure 26. Left Justified Data Formatting: 3200 Hz and 1600 Hz Output Data Rate  
Rev. 0 | Page 24 of 28  
 
 
 
 
Data Sheet  
ADXL313  
AXES OF ACCELERATION SENSITIVITY  
A
Z
A
Y
A
X
Figure 27. Axes of Acceleration Sensitivity (Corresponding Output Increases When Accelerated Along the Sensitive Axis)  
X
Y
Z
= +1g  
= 0g  
= 0g  
OUT  
OUT  
OUT  
TOP  
GRAVITY  
X
Y
Z
= 0g  
= –1g  
= 0g  
X
Y
Z
= 0g  
= +1g  
= 0g  
OUT  
OUT  
OUT  
OUT  
OUT  
OUT  
T O P  
X
Y
Z
= 0g  
= 0g  
= +1g  
X
Y
Z
= 0g  
= 0g  
= –1g  
OUT  
OUT  
OUT  
OUT  
OUT  
OUT  
X
Y
Z
= –1g  
= 0g  
= 0g  
OUT  
OUT  
OUT  
Figure 28. Output Response vs. Orientation to Gravity  
Rev. 0 | Page 25 of 28  
 
ADXL313  
Data Sheet  
SOLDER PROFILE  
SUPPLIER T T  
USER T T  
P
C
P
C
T
C
T
– 5°C  
C
SUPPLIER tP  
USER tP  
T
P
L
T
– 5°C  
C
tP  
MAXIMUM RAMP-UP RATE = 3°C/sec  
MAXIMUM RAMP-DOWN RATE = 6°C/sec  
T
tL  
T
T
SMAX  
PREHEAT AREA  
SMAX  
tS  
25  
TIME 25°C TO PEAK  
TIME  
Figure 29. Recommended Soldering Profile  
Table 20. Recommended Soldering Profile1, 2  
Condition  
Profile Feature  
Sn63/Pb37  
Pb-Free  
Average Ramp Rate (TL to TP)  
Preheat  
3°C/sec maximum  
3°C/sec maximum  
Minimum Temperature (TSMIN  
)
100°C  
150°C  
Maximum Temperature (TSMAX  
Time (TSMIN to TSMAX) (tS)  
TSMAX to TL  
)
150°C  
60 sec to 120 sec  
200°C  
60 sec to 180 sec  
Ramp-Up Rate  
3°C/sec  
3°C/sec  
Time Maintained Above Liquidous (tL)  
Liquidous Temperature (TL)  
Time (tL)  
183°C  
217°C  
60 sec to 150 sec  
240°C + 0°C/−5°C  
10 sec to 30 sec  
6°C/sec maximum  
6 min maximum  
60 sec to 150 sec  
260°C + 0°C/−5°C  
20 sec to 40 sec  
6°C/sec maximum  
8 min maximum  
Peak Temperature (TP)  
Time Within 5°C of Actual Peak Temperature (tP)  
Ramp-Down Rate  
Time 25°C to Peak Temperature  
1 Based on JEDEC standard J-STD-020D.1.  
2 For best results, make sure that the soldering profile is in accordance with the recommendations of the manufacturer of the solder paste used.  
Rev. 0 | Page 26 of 28  
 
 
Data Sheet  
ADXL313  
OUTLINE DIMENSIONS  
5.10  
5.00 SQ  
4.90  
0.30  
0.25  
0.18  
PIN 1  
INDICATOR  
PIN 1  
INDICATOR  
25  
32  
24  
1
0.50  
BSC  
3.70  
3.60 SQ  
3.50  
EXPOSED  
PAD  
17  
8
16  
9
0.45  
0.40  
0.35  
0.20 MIN  
TOP VIEW  
BOTTOM VIEW  
FOR PROPER CONNECTION OF  
THE EXPOSED PAD, REFER TO  
THE PIN CONFIGURATION AND  
FUNCTION DESCRIPTIONS  
1.55  
1.45  
1.35  
0.05 MAX  
0.02 NOM  
SECTION OF THIS DATA SHEET.  
COPLANARITY  
0.05  
0.20 REF  
SEATING  
PLANE  
COMPLIANT TO JEDEC STANDARDS MO-254-LJJD.  
Figure 30. 32-Lead Lead Frame Chip Scale Package [LFCSP_LQ]  
5 mm × 5 mm Body, Thick Quad  
(CP-32-17)  
Dimensions shown in millimeters  
5.34mm  
0.57mm  
0.30mm  
3.60mm  
0.30mm  
0.30mm  
0.50mm  
Figure 31. Sample Solder Pad Layout (Land Pattern)  
Rev. 0 | Page 2± of 28  
 
ADXL313  
Data Sheet  
ORDERING GUIDE  
Measurement  
Range  
Specified  
Voltage (V)  
Temperature  
Range  
Package  
Option  
Model1, 2  
Package Description  
ADXL313WACPZ-RL  
±0.ꢀ g/±1 g/±2 g/±± g 3.3  
−±0°C to +10ꢀ°C  
32-Lead Lead Frame Chip Scale Package CP-32-17  
[LFCSP_LQ]  
ADXL313WACPZ-RL7 ±0.ꢀ g/±1 g/±2 g/±± g 3.3  
−±0°C to +10ꢀ°C  
32-Lead Lead Frame Chip Scale Package CP-32-17  
[LFCSP_LQ]  
EVAL-ADXL313-Z  
EVAL-ADXL313-Z-S  
EVAL-ADXL313-Z-M  
Evaluation Board  
Evaluation Board  
Evaluation Board  
1 Z = RoHS Compliant Part.  
2 W = Qualified for Automotive Applications.  
AUTOMOTIVE PRODUCTS  
The ADXL313W models are available with controlled manufacturing to support the quality and reliability requirements of automotive  
applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers  
should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in  
automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to  
obtain the specific Automotive Reliability reports for these models.  
I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors).  
©2013 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D11469-0-4/13(0)  
Rev. 0 | Page 28 of 28  
 
 
 

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