8g 2 Axis Accelerometer with Programmable Vibration Filter MXC6244AU FEATURES APPLICATIONS High accuracy 2-axis accelerometer: Inclination Sensing in High Vibration o 8g FSR, 1mg/LSB resolution Environments o 0.3 mg/C offset drift over Motorcycle Fall-Down Detection temperature Off-Road Vehicle Roll Detection o 0.5% Sensitivity matching over Jet Ski Roll Detection temperature General Purpose Acceleration Measurements Programmable anti-vibration filter o Attenuation >60dB 50Hz VDD SDA SCK o No sensor resonance Internal angle detection circuit with 8 2-Axis Signal DSP, 3-state programmable thresholds and INT output Sensor Condg Vibration Output INT 400kHz I2C Interface (1.8V compatible) &A/D Filter Driver Built-in self-test functionality Small, 6-pin 3 x 3 x 1 mm LCC package Operates from 2.7 V to 5.5 V Supply Trim & Ref & Clock & Cal Bias Timing High reliability automotive process and Circuits Gen Gen package RoHS compliant GND Operates from -40C to +125C FIGURE 1. FUNCTIONAL BLOCK DIAGRAM DESCRIPTION The MXC6244AU uses MEMSICs proprietary thermal The MXC6244AU is a complete 2 axis accelerometer accelerometer technology. Because the sensing system with a programmable internal anti-vibration element uses heated gas molecules instead of a filter. This filter can provide as much as 45dB attenuation above 25Hz, and 60dB attenuation above mechanical beam structure, the device is extremely 50Hz (see Response to Vibration section). In robust and reliable, with 50,000g shock tolerance, no possibility of stiction, virtually no mechanical addition, the device has 8 built in, I2C programmable resonance, and very high accuracy over temperature. angle thresholds. If the device orientation with respect This makes the device extremely well suited to harsh to vertical exceeds the programmed threshold angle, the INT output changes state to alert the system to a or high vibration environments, where other sensors tip-over or fall down event. This feature can offload the can exhibit false readings due to resonance or other errors. processor from the burden of continuously calculating angles. In the case of an INT, the processor can begin The MXC6244AU runs from a single 2.7V to 5.5V calculating angles to allow for user-defined algorithms supply, and is packaged in a small 6-pin, 3 x 3 x 1 mm to be implemented. LCC package. A built-in self-test function can detect a fault in the internal sensor, and if triggered will cause the INT output to go to a high impedance state. The internal status of the sensor can be read via the I2C interface. Information furnished by MEMSIC is believed to be accurate and reliable. MEMSIC, Inc. However, no responsibility is assumed by MEMSIC for its use, or for any One Technology Drive, Suite 325, Andover, MA01810, USA infringements of patents or other rights of third parties which may result from Tel: +1 978 738 0900 Fax: +1 978 738 0196 its use. No license is granted by implication or otherwise under any patent or www.memsic.com patent rights of MEMSIC. MEMSIC MXC6244AU Rev.C Page 1 of 15 Formal release date: 11/16/2016 SENSOR CHARACTERISTICS: (TA=25C, V = 5V, Fs=3125Hz, unless otherwise specified. Typical values are specified at 25C) DD Parameter Conditions Min Typ Max Units Full Scale Range 8 g TA=25C 975 1024 1075 LSB/g 1 Sensitivity Temperature Drift (-40 to +85C) 6 8.5 % 1,5 X/Y Matching over Temperature (-40 to +85C) 0.3 0.5 % 1 TA=25C 10 30 mg Zero-g Bias 1 Temperature Drift (-40 to +85C) 0.1 0.3 mg/C 40, 42.5, 45, 50, Threshold Angles Programmable via I2C Deg 55, 60, 65, 70 Threshold Accuracy 4 Deg Sensor Bandwidth (Note 2) 11 Hz Total RMS Noise, ODR = 1.5Hz 0.75 Input Referred Noise mg rms Total RMS Noise, ODR = 100Hz 1.5 X-offset (ST 2:0 =111) +2 Offset shift when self-test is g asserted Y-offset (ST 2:0 =111) -2 Resonance (Note 3) Undetectable Hz LOW-g Lockout Threshold (Note 4) 0.375 g Note 1: Established statistically as the average value 3 standard deviations from 30 pieces x 3 lot characterization data Note 2: The sensor has an inherent low pass filter characteristic which is very effective in attenuating out of band vibration. Note 3: The thermal accelerometer sensors use heated gas molecules, and have no measurable resonance Note 4: The LOW-G Lockout featur e disables tip-over detection if the magnitude of both X and Y acceleration vectors fall below 0.375g (as in the case of a free-fall or large off-axis tilt condition). See also Fault Detection. Note 5: Indicates how closely X and Y axis sensitivities change over temperature. MEMSIC MXC6244AU Rev.C Page 2 of 15 Formal release date: 11/16/2016