ETC 2010-050

SILICON DESIGNS, INC
Model 2010
DIGITAL ACCELEROMETER MODULE
! Capacitive Micromachined
! Nitrogen Damped
! Digital Pulse Density Output
! Low Power Consumption
! -55 to +125E
EC Operation
! Rugged Anodized Aluminum Module
! Four Wire Connection
! TTL/CMOS Compatible
! +5 VDC, 2 mA Power (typical)
! Easy Interface to Microprocessors
or the model 3320 G-LOGGERTM
! Good EMI Resistance
! Responds to DC & AC Acceleration
! Non Standard g Ranges Available
! Serialized for Traceability
DESCRIPTION
The model 2010 single axis accelerometer module is designed to be used with the
model 3020 G-LOGGERTM Acceleration Acquisition System. Up to three 2010's
may be connected to a G-LOGGERTM using a model 3901 Cable Adapter. The
2010 contains a model 1010L accelerometer which features a micromachined
capacitive sense element, a custom integrated circuit sense amplifier, and sigmadelta A/D converter. It provides a TTL/CMOS compatible output signal for
measuring accelerations in commercial/industrial environments and 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. An optional calibration
sheet (2010-CAL) and periodic calibration checking are available.
ORDERING INFORMATION
Full Scale
Model
Acceleration
Number
± 2g
± 5g
± 10 g
± 25 g
± 50 g
± 100 g
± 200 g
2010-002
2010-005
2010-010
2010-025
2010-050
2010-100
2010-200
OPERATION
The model 2010 accelerometer produces a digital pulse
train in which the density of pulses (number of pulses per
second) is proportional to applied acceleration. It requires
a single +5VDC power supply and a TTL/CMOS level clock
of 100kHz-1MHz. The output is ratiometric to the clock
frequency and independent of the power supply voltage.
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. External digital line
drivers can be used to drive long cables or when used in
an electrically noisy environment.
SIGNALS
+5V:
GND:
SHIELD:
CLK:
CNT:
DC Power (red wire)
Ground. (black wire, isolated from aluminum case)
Cable shield electrically connected to aluminum case.
Input reference clock; 100Khz-1MHz (white wire).
Count (digital pulse stream) output (green wire)
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 2010 Digital Accelerometer Module
ABSOLUTE MAXIMUM RATINGS *
Operating Temperature (Case & Cable) . . . . -55 to +125EC
Operating Temperature (Connector) . . . . . . . -40 to +65EC
Storage Temperature . . . . . . . . . . . . . . . . . . . -40 to +65EC
Acceleration Over-range . . . . . . . . . . . . . . 2000g for 0.1 ms
Voltage on VDD to GND . . . . . . . . . . . . . . . . . . -0.5V to 6.5V
Voltage on CNT or CLK to GND 1 . . . . . . . . -0.5V to VDD+0.5V
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 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 2010 accelerometer is
a CMOS device subject to damage by large electrostatic
discharges. Diode protection is provided on the inputs and
outputs but care should be exercised during handling of the
connector or cable wire ends (without connector). Individuals
and tools should be grounded before coming in contact with
the connector pins or cable wire ends (without connector).
PERFORMANCE - by Model: VDD=5.0VDC, FCLK=250kHz, TC=25EC.
Model Number
2010-002 2010-005 2010-010 2010-025 2010-050 2010-100 2010-200
Input Range
±2
±5
±10
±25
±50
±100
±200
0 - 400
0 - 600
0 - 1000 0 - 1400 0 - 1600 0 - 1800 0 - 2000
Frequency Response (Nominal, 3 dB)
62.5
25.0
12.5
5.00
2.50
1.25
0.625
Sensitivity (FCLK=250kHz)
2000
Max. Mechanical Shock (0.1 ms)
Units
g
Hz
kHz/g
g
PERFORMANCE - all Models: Unless otherwise specified VDD=5.0 VDC, FCLK=250kHz, TC=25EC.
PARAMETER
Cross Axis Sensitivity
Bias Calibration Error
2
MIN
-002
-005 thru -200
-002
-005 thru -200
Bias Temperature Shift
(TC= -55 to +125EC) 2
Scale Factor Calibration Error 2, 3
Scale Factor Temperature Shift (TC= -55 to +125EC) 2
Non-Linearity
-002 thru -100
(-90 to +90% of Full Scale) 2, 3
-200
Power Supply Rejection Ratio
Operating Voltage
Operating Current 2
Clock Input Voltage Range (with respect to GND)
Mass (not including cable)
Cable Mass
40
4.5
TYP
2
2
1
150
100
1
+300
MAX
3
4
2
400
300
2
% of FCLK (span)
0.5
0.7
1.0
1.5
% of span
5.0
2
5.5
3
VDD+0.5
8
dB
Volts
mA
Volts
grams
25
grams/meter
-0.5
UNITS
%
(ppm of FCLK)/EC
%
ppm/EC
Notes: 1. Voltages on the CLK & CNT signal wires may exceed 0.5 volt above or below the
supply voltage provided the current into or out of the wire is limited to 1 mA.
2. Tighter tolerances available on special order.
3. 100g versions and above are tested from -65 to +65g.
CONNECTOR: Switchcraft model EN3C6F (mating connector EN3L6M).
ALTERNATE OUTPUT VERSION AVAILABLE: A custom version may be ordered which provides the DIR (direction) output
instead of the CNT (count) output. For a description of the DIR signal, see the model 1010 data sheet.
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 2010 Digital Accelerometer Module
SIGNAL DESCRIPTIONS
CLK (input): Reference clock input. This hysteresis threshold input must be driven by a 50% duty cycle square wave
signal. Factory Calibration is performed at 250 kHz but the 2210 will operate at frequencies as low as 100 kHz or as
high as 1 MHz.
CNT (output): Count output. A return-to-zero type digital pulse stream whose pulse width is equal to the input CLK logic
high time. The CNT pulse rate increases with positive acceleration. The device experiences positive (+1g)
acceleration with its lid facing up in the earth’s gravitational field. This signal is meant to drive an up-counter directly.
Pulses from the CNT output are meant to be accumulated in a hardware counter. Each pulse accumulation or sample,
reflects the average acceleration (change in velocity) over that interval. The sample period or “gate time” over which these
pulses are accumulated determines both the bandwidth and quantization of the measurement.
Quantization (g' s) =
g SPAN • f SR
fCLK
 1 g FORCE 

f CNT = f CLK  +
 2 g SPAN 
 f
1
g FORCE = g SPAN  CNT − 
 f CLK 2 
Where:
gSPAN = 2 * ( full scale acceleration in g' s)
f SR = CNT sample rate in Hertz
fCLK = accelerometer clock rate in Hertz
fCNT = CNT pulse rate in pulses / sec
g FORCE = acceleration in gravity units
1 g = 9.807 m / s2 or 32.175ft / s 2
The first equation above shows that as the sample rate is reduced (i.e. a longer sample period), the quantization becomes
finer but bandwidth is reduced. Conversely, as the sample rate is increased, quantization becomes coarser but the
bandwidth of the measurement is increased. The second and third equations show how the CNT pulse frequency equates
to the applied g-force. When using a frequency counter to monitor the CNT output pulse rate, a counter with a DC coupled
input must be used. The CNT output is a return-to-zero signal whose duty cycle varies from zero to fifty percent, from minus
full scale to positive full scale acceleration. A frequency counter with an AC coupled input will provide an erroneous
reading as the duty cycle varies appreciably from fifty percent.
CABLE LENGTH CONSIDERATIONS
Cable lengths of up to 45 meters (150 feet) can be added to the model 2010's standard 1 meter cable when it is connected
to a Model 3901 Adapter Cable and is being used with a Model 3320 G-LOGGERTM. The extension cable must however,
be a longer version of the G-LOGGERTM 9 conductor flat cable instead of the 2010's round cable to reduce crosstalk
between the CNT and CLK signals. 15 meter (50 foot) cable lengths of DB9 male to DB9 female flat extension cable are
available on special order.
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