Page 1
3-axis ±2 g analog-output "piccolo" accelerometer
Features
■ Single voltage supply operation
■ ±2 g full-scale
■ 3 acceleration channels plus multiplexed
analog output
■ Ratiometric output voltage
■ Power-down mode
■ Embedded self-test
■ 10000 g high shock survivability
■ ECOPACK
(see Section 7)
Applications
■ Free-fall detection for data protection
■ Tilting applications
■ Gaming and virtual reality input devices
■ Antitheft systems and inertial navigation
®
RoHS and “Green” compliant
LIS352AR
MEMS motion sensor:
LGA-14
capacitors. The self-test capability allows the user
to check the functioning of the sensor in the final
application.
The device has three analog acceleration outputs,
plus an embedded multiplexer that allows for
redirection of the analog outputs onto a single pin
for operation with a single-channel A/D converter.
ST is already in the field with several hundred
million sensors which have received excellent
acceptance from the market in terms of quality,
reliability and performance
(3x5x0.9mm)
Description
The LIS352AR is a miniaturized low-power 3-axis
linear accelerometer belonging to the “piccolo”
family of ST motion sensors. It includes a sensing
element and an IC interface to provide an analog
signal to the external world.
The LIS352AR is provided in a plastic land grid
array (LGA) package.
Several years ago ST successfully pioneered the
usage of this package for accelerometers. Today,
ST has the widest manufacturing capability and
strongest expertise in the world for production of
sensors in plastic LGA packages.
The sensing element, capable of detecting the
acceleration, is manufactured using a dedicated
process developed by ST to produce motion
sensors and actuators in silicon.
The IC interface is manufactured using a CMOS
process that allows the design of a dedicated
circuit which is trimmed to better match the
sensing element characteristics.
Table 1. Device summary
Order code
LIS352AR -40 to +85 LGA-14 Tray
LIS352ARTR -40 to +85 LGA-14 Tape and reel
Temp.
range [°C]
Package Packing
The LIS352AR has a full-scale of ±2 g and is
capable of measuring accelerations over a
maximum bandwidth of 2.0 kHz. The device
bandwidth may be reduced by using external
February 2010 Doc ID 16933 Rev 1 1/15
www.st.com
15
Page 2
Contents LIS352AR
Contents
1 Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Pin connections and description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Mechanical and electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Mechanical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Zero-g level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.3 Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.4 Output impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 Sensing element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2 IC interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.3 Factory calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1 Soldering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.2 Output response vs. orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2/15 Doc ID 16933 Rev 1
Page 3
LIS352AR Block diagram and pin description
1 Block diagram and pin description
Figure 1. Block diagram
a
SELF-TEST
X+
Y+
Z+
MUX
ZYX-
REFERENCE
CHARGE
AMPLIFIER
TRIMMING CIRCUIT
DEMUX
Routx
S/H
Routy
S/H
Routz
S/H
CLOCK
Aux_in
Voutx
Vouty
Voutz
Vout
MUX
S1 S0
AM06049v1
1.1 Pin connections and description
Figure 2. Pin connection
Z
X
Y
(TOP VIEW)
DIRECTIONS OF
DETECTABLE
ACCELERATIONS
1
Vdd
Aux_in
Vout
GND
Voutz
Vouty
Reserved
13
8
1
6
Voutx
(BOTTOM VIEW)
NC
Reserved
S0
S1
ST
PD
AM06050v1
Doc ID 16933 Rev 1 3/15
Page 4
Block diagram and pin description LIS352AR
Table 2. Pin description
Pin # Pin name Function
1 NC Internally not connected
2 Reserved Connect to Vdd
3 S0 Mux selector 0 (connect to Vdd or to GND)
4 S1 Mux selector 1 (connect to Vdd or to GND)
5 ST Self-test (logic 0: normal mode; logic 1: self-test)
6 PD Power-down (logic 0: normal mode; logic 1: power-down mode)
7 Voutx Output voltage X channel
8 Vouty Output voltage Y channel
9 Voutz Output voltage Z channel
10 GND 0 V supply
11 Vout Multiplexer output
12 Aux_In Auxiliary input
13 Vdd Power supply
14 Reserved Connect to Vdd
4/15 Doc ID 16933 Rev 1
Page 5
LIS352AR Mechanical and electrical specifications
2 Mechanical and electrical specifications
2.1 Mechanical characteristics
@ Vdd=3.3 V, T=25 °C unless otherwise noted
Table 3. Mechanical characteristics
Symbol Parameter Test condition Min. Typ.
Ar Acceleration range
(2)
(a)
.
(1)
±2 g
Max. Unit
So Sensitivity
SoDr
Sensitivity change vs.
temperature
Voff Zero-g level
OffDr
Zero-g level change
Vs temperature
NL Non linearity
CrossAx Cross-axis
Acceleration noise
An
density
Self-test output
Vt
voltage change
Fres
Sensing element
resonant frequency
(3)
(5)
(4)
(4)
(6),(7)
0.145*Vdd
–5%
0.145*Vdd
0.145*Vdd
+ 5%
Delta from +25 °C ±0.01 %/°C
T = 25 °C Vdd/2-6% Vdd/2 Vdd/2+6% V
Delta from +25 °C ±0.3 mg/°C
Best fit straight line ±0.5 % FS
±2 %
Vdd=3.3 V 100 µg/
T = 25 °C
Vdd=3.3 V
60 900 mV
X axis
T = 25 °C
Vdd=3.3 V
60 900 mV
Y axis
T = 25 °C
Vdd=3.3 V
60 900 mV
Z axis
All axes 2.0 kHz
(8)
V/g
Hz
Top
Operating
temperature range
Wh Product weight 30 mgram
1. Typical specifications are not guaranteed
2. Guaranteed by wafer level test and measurement of initial offset and sensitivity
3. Zero-g level and sensitivity are ratiometric to supply voltage
4. Guaranteed by design
a. The product is factory calibrated at 3.3 V. The operational power supply range is specified in Table 4. Since the
device is ratiometric, Voff, So and Vt parameters will vary with supply voltage.
Doc ID 16933 Rev 1 5/15
-40 +85 °C
Page 6
Mechanical and electrical specifications LIS352AR
5. Contribution to the measuring output of an inclination/acceleration along any perpendicular axis
6. “Self-test output voltage change” is defined as Vout
7. “Self-test output voltage change” varies cubically with supply voltage
8. Minimum resonance frequency Fres=2.0 kHz. Sensor bandwidth=1/(2*π*32kΩ*Cload), with Cload>2.5 nF
(Vst=logic 1)
-Vout
(Vst=logic 0)
2.2 Electrical characteristics
@ Vdd=3.3 V, T=25 °C unless otherwise noted
Table 4. Electrical characteristics
Symbol Parameter Test condition Min. Typ.
Vdd Supply voltage 2.16 3.3 3.6 V
Idd Supply current
IddPdn
Supply current in
power-down mode
Mean value
PD pin connected to GND
PD pin connected to Vdd 1 µA
(b)
(1)
Max. Unit
0.3 mA
Vst
Vpd
Self-test input
Power-down input
Vs0 S0 Input
Vs1 S1 input
Rout
Output impedance of
Voutx, Vout y, Vout z
Capacitive load drive
Cload
fo r Vo u t x , Vo u ty,
(2)
Voutz
Series resistance of
Rmux
multiplexer input vs.
Vout
Capacitive load drive
Cloadmux
for multiplexed output
Vout
Turn-on time at exit
To n
from power-down
mode
To p
1. Typical specifications are not guaranteed
2. Minimum resonance frequency F
Operating
temperature range
Logic 0 level at Vdd=3.3 V 0 0.2*Vdd
Logic 1 level at Vdd=3.3 V 0.8*Vdd Vdd
Logic 0 level at Vdd=3.3 V 0 0.2*Vdd
Logic 1 level at Vdd=3.3 V 0.8*Vdd Vdd
Logic 0 level at Vdd=3.3 V 0 0.2*Vdd
Logic 1 level at Vdd=3.3 V 0.8*Vdd Vdd
32 kΩ
2.5 nF
1
10 pF
C
in µF 160*C
LOAD
LOAD
-40 +85 °C
=2.0 kHz. Device bandwidth=1/(2*π*32kΩ*C
RES
LOAD
), with C
LOAD
V
V
V
k
+0.3 ms
>2.5 nF
Ω
b. The product is factory calibrated at 3.3 V.
6/15 Doc ID 16933 Rev 1
Page 7
LIS352AR Absolute maximum ratings
3 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 5. Absolute maximum ratings
Symbol Ratings Maximum value Unit
Vdd Supply voltage -0.3 to 6 V
Vin Input voltage on any control pin (PD, ST, S0, S1) -0.3 to Vdd +0.3 V
V
Aux_in
A
A
T
Aux_in input voltage -0.3 to Vdd +0.3 V
Acceleration (any axis, powered, Vdd=3.3 V)
POW
Acceleration (any axis, not powered)
UNP
Storage temperature range -40 to +125 °C
STG
ESD Electrostatic discharge protection
Note: Supply voltage on any pin should never exceed 6.0 V.
This is a mechanical shock sensitive device, improper handling can cause permanent
damages to the part
This is an ESD sensitive device, improper handling can cause permanent damages to
the part
3000 g for 0.5 ms
10000 g for 0.1 ms
3000 g for 0.5 ms
10000 g for 0.1 ms
4 (HBM) kV
1.5 (CDM) kV
200 (MM) V
Doc ID 16933 Rev 1 7/15
Page 8
Terminology LIS352AR
4 Terminology
4.1 Sensitivity
Sensitivity describes the gain of the sensor and can be determined by applying 1 g
acceleration to it. Because the sensor can measure DC accelerations, this can be done
easily by pointing the selected axis towards the ground, noting the output value, rotating the
sensor 180 degrees (pointing towards the sky) and noting the output value again. By doing
so, a ±1 g acceleration is applied to the sensor. Subtracting the larger output value from the
smaller one, and dividing the result by 2, produces the actual sensitivity of the sensor. This
value changes very little over temperature (see sensitivity change vs. temperature) and over
time. The sensitivity tolerance describes the range of sensitivities of a large number of
sensors.
4.2 Zero-g level
Zero-g level describes the actual output signal if there is no acceleration present. A sensor
in a steady state on a horizontal surface will measure 0 g on both the X and Y axes,
whereas the Z axis will measure 1 g. Ideally, the output for a 3.3 V powered sensor Vdd/2 =
1650 mV. A deviation from ideal 0 g level (1500 mV, in this case) is called Zero-g 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
change vs. temperature” in Table 3: Mechanical characteristics). The Zero-g level of an
individual sensor is also very stable over its lifetime. The Zero-g level tolerance describes
the range of Zero-g levels of a group of sensors.
4.3 Self-test
Self-test (ST) allows the checking of sensor functionality without moving it. The self-test
function is off when the ST pin is connected to GND. When the ST pin is tied to Vdd, an
actuation force is applied to the sensor, simulating a definite input acceleration. In this case,
the sensor outputs exhibit a voltage change in their DC levels. When ST 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 3, then the sensor is working properly and the parameters
of the interface chip are within the defined specifications.
4.4 Output impedance
Output impedance describes the resistor inside the output stage of each channel. This
resistor is part of a filter consisting of an external capacitor of at least 2.5 nF and the internal
resistor. Due to the resistor level, only small inexpensive external capacitors are needed to
8/15 Doc ID 16933 Rev 1
generate low corner frequencies. When interfacing with an ADC, it is important to use high
input impedance input circuitries to avoid measurement errors. Note that the minimum load
capacitance forms a corner frequency close to the resonant frequency of the sensor. In
general, the smallest possible bandwidth for a particular application should be chosen to
obtain the best results.
Page 9
LIS352AR Functionality
5 Functionality
The LIS352AR is a 3-axis “piccolo”, low-power, analog output linear accelerometer
packaged in an LGA package. The complete device includes a sensing element and an IC
interface capable of taking information from the sensing element providing an analog signal
to the external world. The sensor provides three acceleration channels and one multiplexed
analog output.
5.1 Sensing element
A proprietary process is used to create a surface micro-machined accelerometer. The
technology allows the creation of suspended silicon structures which are attached to the
substrate at several points called “anchors” and are free to move in the direction of the
sensed acceleration. To be compatible with traditional packaging techniques, a cap is
placed on top of the sensing element to prevent blocking of the moving parts during the
moulding phase of plastic encapsulation.
When an acceleration is applied to the sensor, the proof mass shifts from its nominal
position, causing an imbalance in the capacitive half-bridge. This imbalance is measured
using charge integration in response to a voltage pulse applied to the sense capacitor.
At steady state, the nominal value of the capacitors are a few pF, and when an acceleration
is applied the maximum variation of the capacitive load is in the fF range.
5.2 IC interface
The complete signal processing utilizes a fully differential structure, while the final stage
converts the differential signal into a single-ended signal to be compatible with external
applications.
The first stage is a low-noise capacitive amplifier that implements a correlated double
sampling (CDS) at its output to cancel the offset and the 1/f noise. The signal produced is
then sent to three different S&Hs, one for each channel, and made available to the outside.
The device provides an embedded multiplexer to allow the redirection of either the analog
output signals Voutx, Vouty, and Voutz, or of an auxiliary input signal onto a single pin for
operation with a single-channel A/D converter.
All the analog parameters (output offset voltage and sensitivity) are ratiometric to the
voltage supply. Increasing or decreasing the voltage supply, the sensitivity and the offset
increases or decreases linearly. This feature provides for cancellation of the error related to
the voltage supply along an analog-to-digital conversion chain.
5.3 Factory calibration
The IC interface is factory-calibrated for sensitivity (So) and Zero-g level (Voff). The trimming
values are stored in the device in a non-volatile structure. Any time the device is turned on,
the trimming parameters are downloaded to the registers to be employed during normal
operation. This allows the user to use the device without further calibration.
Doc ID 16933 Rev 1 9/15
Page 10
Application hints LIS352AR
6 Application hints
Figure 3. LIS352AR electrical connection
,)3!2
TOPVIEW
#LOADZ
6DD
#LOADMUX
'.$
N&
!UX)N
'.$'.$
&
/PTIONAL
/PTIONAL
6OU T
6OU T :
:
8
9
$)2%#4)/.3/&
$%4%#4!", %
!##%,%2!4)/. 3
0ININDICATOR
6DD
3
3
34
0$
!NALOGSIGNALS
$IGITALSIGNALS
#LOADY
#LOAD
/PTIONAL
/PTIONAL
X
6OU T 9
6OUT8
!-V
Power supply decoupling capacitors (100 nF ceramic or polyester + 10 µF aluminum) should
be placed as near as possible to the device (common design practice).
The LIS352AR allows band limiting of Voutx, Vouty and Voutz through the use of external
capacitors. The recommended frequency range spans from DC up to 2.0 kHz. Capacitors
must be added at the output pins to implement low-pass filtering for anti-aliasing and noise
reduction, even if only the multiplexed output (Vout) is used. The equation for the cut-off
frequency ( f
Taking into account that the internal filtering resistor (R
) of the external filters is:
t
f
t
------------------------------------------------------------------------=
2π R
out
1
C
load
xyz,,()⋅⋅
) has a nominal value of 32 kΩ, the
out
equation for the external filter cut-off frequency may be simplified as follows:
f
t
10/15 Doc ID 16933 Rev 1
load
5µF
xyz,,()
-------------------------------------- -
C
Hz[]=
Page 11
LIS352AR Application hints
The tolerance of the internal resistor can vary ±15% (typ) from its nominal value of 32 kΩ;
thus the cut-off frequency will vary accordingly. A minimum capacitance of 2.5 nF for C
LOAD
(x, y, z) is required.
An external capacitor can be added to the Vout pin. Values below 10 pF are recommended.
Table 6. Filter capacitor selection, C
Cut-off frequency Capacitor value
1 Hz 5 µF
10 Hz 0.5 µF
20 Hz 250 nF
50 Hz 100 nF
100 Hz 50 nF
200 Hz 25 nF
500 Hz 10 nF
Table 7. MUX I/O table
S1 pin S0 pin MUX status
0 0 Vout = Voutx
0 1 Vout = Vouty
1 0 Vout = Voutz
11 Vout = Aux_in
LOAD
(x,y,z)
6.1 Soldering information
The LGA package is compliant with the ECOPACK®, RoHs and “Green” standard.
It is qualified for soldering heat resistance according to JEDEC J-STD-020C.
Leave “pin 1 Indicator” unconnected during soldering.
Land pattern and soldering recommendations are available at www.st.com.
Doc ID 16933 Rev 1 11/15
Page 12
Application hints LIS352AR
6.2 Output response vs. orientation
Figure 4. Output response vs. orientation
X=1.17V (-1g)
Y=1.65V (0g)
Z=1.65V (0g)
X=1.65V (0g)
Y=2.13V (+1g)
Z=1.65V (0g)
X=2.13V (+1g)
Y=1.65V (0g)
Z=1.65V (0g)
Figure 4 refers to the LIS352AR powered at 3.3 V.
X=1.65V (0g)
Y=1.17V (-1g)
Z=1.65V (0g)
Bottom
To p
To p
Bottom
Earth’ surface
X=1.65V (0g)
Y=1.65V (0g)
Z=1.17V(-1g)
X=1.65V (0g)
Y=1.65V (0g)
Z=2.13V (+1g)
12/15 Doc ID 16933 Rev 1
Page 13
LIS352AR Package information
7 Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK
®
packages, depending on their level of environmental compliance. ECOPACK®
®
is an ST trademark.
Figure 5. LGA-14: mechanical data and package dimensions
Dimensions
mm inch
Ref.
Min. Typ. Max. Min. Typ. Max.
A1 0.90 1 0.033 0.035 0.037
A2 0.7 0.027
A3 0.16 0.2 0.24 0.006 0.007 0.009
D1 2.85 33.15 0.116 0.118 0.120
E1 4.85 5 5.15 0.194 0.196 0.198
N1 0.8 0.031
L1 4 0.157
P1 1.34 0.052
P2 1.2 0.047 0.048
T1 0.8 0.031
T2 0.5 0.019
d 0.15 0.005
M 0.1 0.003
k 0.05 0.002
Outline and
mechanical data
LGA-14 (3x5x0.9mm)
pitch 0.8mm
Land Grid Array Package
7773587E
Doc ID 16933 Rev 1 13/15
Page 14
Revision history LIS352AR
8 Revision history
Table 8. Document revision history
Date Revision Changes
02-Feb-2010 1 Initial release.
14/15 Doc ID 16933 Rev 1
Page 15
LIS352AR
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Doc ID 16933 Rev 1 15/15
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