a Data Sheet

CXTA
Solid state, analog series
• Small, Low-Cost, Rugged
• Rapid Response
• ± 75° Range
• Fully Conditioned
Analog Outputs
Applications
• Scissor Lifts
• Static Platforms
• Survey Leveling Equipment
• Laser Leveling
CXTA01, CXTA02
The CXTA single- and dual-axis
analog tilt sensors offer resolution,
accuracy, and fast response in an
inexpensive, easy-to-use package.
The CXTA series design centers on a
highly stable silicon micro-machined
capacitive inclination sensor element. The CXTA series is fully signal
conditioned with high level analog
output(s), and optional analog temperature signal.
Micro-machined devices, perfected in
automotive safety applications, offer
several distinct advantages over fluid,
electrolytic, and pendulum-based
sensors. Like other solid-state devices,
they are more reliable than their mechanical counterparts. In a package
smaller than many pendulum or fluid
raw sensing elements, completely
integrated electronics eliminate the
need for external components.
Unlike other micro-machined devices,
the CXTA Series maintains its accuracy and stability over temperature:
< 2° of arc over the range 0° to 70° C.
The output can be user corrected for
temperature with the T option, yielding accuracy to within ± 0.5° over the
angular range.
A typical configuration using CXTA
sensors is shown below. Each module is factory calibrated, tested and
includes a calibration sheet. The
module can be securely attached using screws or adhesive. The CXTA is
available in a standard nylon or high
temperature aluminum package.
6-30V
GND
CXTA02
Power
Supply
Xout
Yout
A/D
Converter
Temp (optional)
Typical CXTA02 Configuration
Micromachined
Tilt Sensor Element
Phone: 408.964.9700
Fax: 408.854.7702
E-mail: infoca@memsic.com
w w w. m e m s i c . c o m
Specifications
CXTA01
CXTA02
Remarks
Linear Angular Range (°)
± 20
± 20
Full Angular Range (°)
± 75
± 75
Angular Resolution (° rms)
0.05
0.05
Sensitivity - small angles (mV/O)
35 ± 2
35 ± 2
Sensitivity Drift (%/OC)
0.01
0.01
Zero Angle Voltage (Volts)
2.5 ± 0.15
2.5 ± 0.15
Actual value provided with Sensor
Zero Angle Drift (mV/OC)
1.0
1.0
Typical
Zero Angle Drift / C)
0.03
0.03
Non-Linearity (°)
< 0.4
< 0.4
Typical
Over ± 20O not including Arcsine Error
Bandwidth (Hz)
50
50
Settling Time (sec)
0.2
0.2
Alignment (°)
±1
±1
Typical
Cross-axis Sensitivity (%))
<5
<5
Inclusive of alignment error
-55 to +85
Nylon Package
-40 to +85
Nylon Package
-55 to +105
-AL High Temperature Package
Performance
(O O
Actual value provided with Sensor
ø
ø = sin-1 Vout (V) - Zero Angle Voltage (V)
Sensitivity
(V/rad)
Environment
Storage Temperature (OC)
Operating Temperature (OC)
Storage Temperature (OC)
-55 to +85
-40 to +85
-55 to +105
Operating Temperature ( C)
-40 to +105
-40 to +105
-AL High Temperature Package
Non-Operating Vibration (g rms)
10
10
20-2 kHz random
Shock (g)
2000
2000
1 ms, half sine
Supply Voltage (VDC)
6 - 30
6 - 30
Unregulated
Current (mA)
4
8
O
Figure 1
Sensitivity (V/rad)
Electrical
Physical
Size (Nylon Package)
.78 x 1.75 x 1.07” (1.98 x 4.45 x 2.72 cm)
(Aluminum Package)
.95 x 2.00 x 1.20“ (2.41 x 5.08 x 3.05 cm)
Weight (Nylon Package)
1.38 oz (43 gm)
(Aluminum Package)
2.09 oz (65 gm)
Specifications subject to change without notice
Principle of Operation
Using the CXTA Sensor
The CXTA Series Tilt Sensors use a
micro-machined acceleration sensing
element with a DC response to measure inclination relative to gravity. The response of the tilt sensor depends on the magnitude of gravity
parallel to the sensor element. The
output of the tilt sensor will be an
offset voltage plus the voltage response proportional to the amount
of gravity measured by the sensor.
The voltage response of the CXTA
is proportional to the sine of the tilt
angle.
Accurately measuring tilt angle involves solving the equation shown
in Figure 1. To solve this equation the
Zero Angle Voltage and Sensitivity
must be determined prior to use, and
the sensitivity must be converted to
V/rad. MEMSIC provides this information on a calibration sheet with its
CXTA products.
ø = Vout - Zero Angle Voltage
Sensitivity
For angles less than 20°, the sine
function can be approximated by a
linear relationship between the Vout
and the tilt angle in degrees. Thus
the simplified equation for small
angle in degrees is:
When the tilt angle is less than 20°,
the error from linear approximation
will be less than 2%. This is convenient when you don’t have or want
the computing power to calculate an inverse sine function.
Pin
Color
Function
1
Red
Power
2
Black
Ground
3
White
Roll
4
Yellow
Pitch
5
Green
Temp
Pin Diagram
Ordering Information
Model
CXTA01
CXTA02
Axes
X
X,Y
Linear Range
Full Range
Resolution
± 20º
± 75º
0.05º
± 20º
± 75º
0.05º
OPTIONS
Optional Aluminum Package
-T
Temperature Sensor Internal
-AL
High Temperature Aluminum Package
call factory for other configurations
MEMSIC Inc.
San Jose, California
w w w. m e m s i c . c o m
6020-0013-03 Rev A