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: [email protected] 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