SILICON DESIGNS, INC
!
Capacitive Micromachined
!
Nitrogen Damped
!
±4V Differential Output or
0.5V to 4.5V Single Ended Output
!
Fully Calibrated
!
Low Power Consumption
!
-55 to +125EC Operation
E
!
+5V DC Power
!
Simple, Four Wire Connection
!
Serialized for Traceability
!
Responds to DC & AC Acceleration
!
Non Standard Ranges Available
!
Rugged Black Anodized Aluminum Module
Model 2012
ANALOG ACCELEROMETER MODULE
ACTUAL SIZE
ORDERING INFORMATION
Full Scale
Acceleration
± 2g
± 5g
± 10 g
± 25 g
± 50 g
±100 g
±200 g
±400 g
Model
Number
2012-002
2012-005
2012-010
2012-025
2012-050
2012-100
2012-200
2012-400
DESCRIPTION
The Model 2012 accelerometer module provides a rugged protective case around
an integrated model 1210L accelerometer for measuring accelerations in
commercial/industrial environments. It is tailored for zero to medium frequency
instrumentation applications. The anodized aluminum case is epoxy sealed and
is easily mounted via two #4 (or M3) screws. It is relatively insensitive to
temperature changes and gradients. The cable’s shield is electrically connected
to the case while the ground (GND) wire is isolated from the case. An optional initial
calibration sheet (2012-CAL) and periodic calibration checking are also available.
Please refer to the Model 2210 for applications that require a lower output
impedance or greater power supply rejection ratio than the Model 2012 provides.
OPERATION
The Model 2012 accelerometer module produces two
analog voltage outputs,
AOP
&
AON,
which vary with
acceleration as shown in the graph at right. The signal
outputs are fully differential about a common mode
voltage of ½ V
DD
(approximately 2.5 volts). At zero
acceleration, the output differential voltage is nominally
zero volts; at +full scale acceleration, the output
differential voltage is +4 volts; at -full scale acceleration
the output differential voltage is -4 volts. The sensitive
axis is perpendicular to the bottom of the package, with
positive acceleration defined as a force pushing on the
bottom of the package.
SIGNAL DESCRIPTIONS
V
DD
and GND (Power):
Red and Black wires respectively. Power (+5 Volts DC)
and ground.
AOP and AON (Output):
Green & white wires respectively. AOP voltage
increases (AON decreases) with positive acceleration. At zero acceleration,
both outputs are nominally equal to 2.5 volts. The device experiences positive
(+1g) acceleration with its lid facing up in the Earth’s gravitational field. Either
output can be used individually or the pair can be used differentially
.
APPLICATIONS
VIBRATION MONITORING
VIBRATION ANALYSIS
MACHINE CONTROL
MODAL ANALYSIS
ROBOTICS
CRASH TESTING
INSTRUMENTATION
ROTATING MACHINERY
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc.
!
1445-NW Mall Street, Issaquah, WA 98027-5344
!
Phone: 425-391-8329
!
Fax: 425-391-0446
web site:
www.silicondesigns.com
[page 1]
Sep 07
Model
2012
Analog Accelerometer Module
ABSOLUTE MAXIMUM RATINGS
*
Case Operating Temperature . . . . . . . . . . . . . . -55 to +125EC
Storage Temperature . . . . . . . . . . . . . . . . . . . . -55 to +125EC
Acceleration Over-range . . . . . . . . . . . . . . . . 2000g for 0.1 ms
Voltage on V
DD
to GND . . . . . . . . . . . . . . . . . . . . -0.5V to 6.5V
Voltage on AOP or AON to GND
1
. . . . . . . -0.5V to V
DD
+0.5V
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 mW
* NOTICE:
Stresses above those listed under "Absolute
Maximum Ratings" may cause permanent damage to the device.
These are stress ratings only. Functional operation of the
device at or above these conditions is not implied. Exposure to
absolute maximum rating conditions for extended periods may
affect device reliability.
ESD CONSIDERATIONS:
The model 2012 accelerometer is a CMOS device subject to
damage by large electrostatic discharges. Diode protection is
provided on the outputs but care should be exercised during
handling of the cable wire ends. Individuals and tools should be
grounded before coming in contact with the cable wire ends.
PERFORMANCE - By Model:
V
DD
=+5VDC, T
C
=25EC.
2012-002 2012-005 2012-010 2012-025 2012-050 2012-100 2012-200 2012-400
Units
±5
±10
±10
±25
±50
±100
±200
±200
g
Hz
Frequency Response
(Nominal, 3 dB)
0 - 300 0 - 400 0 - 600 0 - 1000 0 - 1600 0 - 2000 0 - 2500 0 - 3000
2
Sensitivity - Differential
2000
800
400
160
80
40
20
10
mV/g
13
32
63
158
316
632
1265
2530
µg/(root
Hz)
Output Noise
(differential RMS, typical)
2000
g
Max. Mechanical Shock
(0.1 ms)
MODEL NUMBER
Input Range
PERFORMANCE - All Models:
Unless otherwise specified, V
DD
=+5VDC, T
C
=25EC, Differential Mode.
PARAMETER
Cross Axis Sensitivity
Bias Calibration Error
3
Min
-002
-005
-010 thru -400
-002 & -005
-010 thru -400
Typ
2
2
1
1
100
50
1
+300
0.5
0.7
1.0
25
90
5.0
8
8
Max
3
4
3
2
300
200
2
1.0
1.5
2.0
Units
%
% of span
Bias Temperature Shift
(T
C
= -55 to +125EC)
3
Scale Factor Calibration Error
3, 4
(ppm of span)/EC
%
ppm/EC
% of span
dB
Scale Factor Temperature Shift
(T
C
= -55 to +125EC)
3
Non-Linearity
(-90 to +90% of Full Scale)
3, 4
Power Supply Rejection Ratio
Output Impedance
Operating Voltage
Operating Current
3
-002 thru -100
-200
-400
4.75
5.25
10
V
mA
grams
Mass
(not including cable)
Cable Mass
25
grams/meter
Notes:
1. Voltages on the
AOP
&
AON
signal wires may exceed 0.5 volt above or below the supply voltages provided the current is limited to 1 mA.
2. Single ended sensitivity is half of values shown.
3. Tighter tolerances available on special order.
4. 100g versions and above are tested from -65g to +65g.
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc.
!
1445-NW Mall Street, Issaquah, WA 98027-5344
!
Phone: 425-391-8329
!
Fax: 425-391-0446
web site:
www.silicondesigns.com
[page 2]
Sep 07
Model
2012
Analog Accelerometer Module
CABLE SPECIFICATIONS & LENGTH CONSIDERATIONS
The cable consists of four 26 AWG (7x34) silver plated copper wires with PTFE insulation surrounded by a braided shield. The
shield jacket is a PTFE tape wrap with a nominal outer diameter of 0.131”. Extending the model 2012's one meter cable is not
recommended. If you do decide to connect additional cable, we recommend you check each individual installation for oscillation
by tapping the accelerometer and watching the differential output for oscillation in the 20kHz to 50kHz region. If no oscillation
is present, then the additional cable length being used is OK for that particular device.
CONVERTING THE 2012's DIFFERENTIAL OUTPUT TO SINGLE ENDED
C1 = C2 (See below for value calculation)
R1, R2, R3 & R4 = 20k to 50k
R1 = R3 to within 0.1% for good common mode rejection
R2 = R4 to within 0.1% for good common mode rejection
R2 / R1 ratio accurate to within 0.1% for gain control
R4 / R3 ratio accurate to within 0.1% for gain control
To achieve the highest resolution and lowest noise performance from your model 2012 accelerometer module, it should
be connected to your voltage measurement instrument in a differential configuration using both the
AOP
and
AON
output
signals. If your measurement instrument lacks differential input capability or you desire to use a differential input capable
instrument in single ended mode, then the circuit above can be used to preserve the low noise performance of the model
2012 while using a single ended type connection.
This circuit converts the ± 4 Volt differential output of the model 2012 accelerometer, centered at +2.5 Volts, to a single
ended output centered about ground (0.0 Volts). It provides the advantage of low common mode noise by preventing the
accelerometer’s ground current from causing an error in the voltage reading.
The op-amp should be located as close as possible to your voltage monitoring equipment so that the majority of the signal
path is differential. Any noise present along the differential path will affect both wires to the same degree and the op-amp
will reject this noise because it is a common mode signal. The op-amp type is not critical; a
µA741
or ¼ of a LM124 can
be used. Both plus and minus supplies are needed for the op-amp to accommodate the positive and negative swings of
the single ended output. The same +5V supply can be used for both the op-amp and the 2012 or a higher voltage positive
supply can be used for the op-amp if you need a larger single ended output swing.
For this design, always set R
1
= R
3
, R
2
= R
4
and C
1
= C
2
. The gain of the circuit is then determined by the ratio R
2
/R
1
.
When R
1
= R
2
= R
3
= R
4
, the gain equals 1 and the output swing will be ± 4 Volts single ended with respect to ground. To
obtain a ± 5 Volt single ended output, set R
2
/R
1
= R
4
/R
3
= 5/4 = 1.25. The single ended output of the op-amp will be
centered at ground if R
2
and C
1
are tied to ground; using some other fixed voltage for this reference will shift the output.
The value of the optional capacitors C
1
and C
2
(C
1
= C
2
) can be selected to roll off the frequency response to the frequency
range of interest. The cutoff frequency
f
0
(-3 dB frequency) for this single order low pass filter is given by:
f
0
=
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
1
2
π
R
2
C
1
Silicon Designs, Inc.
!
1445-NW Mall Street, Issaquah, WA 98027-5344
!
Phone: 425-391-8329
!
Fax: 425-391-0446
web site:
www.silicondesigns.com
[page 3]
Sep 07
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