MEMS-technology, vibration filtering accelerometers & tilt switches

June 24, 2016 // By Graham Prophet
Sensors by MEMSIC offer low cost, robust and accurate sensing solutions for cars, motorcycles, off road vehicles & equipment, cameras, drones and other consumer and industrial applications; specifically, reliably detecting tip-over condition in high vibration environments.

MEMSIC has added family of acceleration and tip-over sensor components that includes four new sensors, the MXD6240 and 41AU, MXC6244AU, MXC6245XU. “For years, high vibration environments have caused problems for accelerometers, forcing customers to widen the full scale range of the accelerometer to prevent clipping and move to a more powerful and expensive microprocessor capable of higher sampling rates and heavy filtering needed to prevent aliasing and recover the signal of interest,” said James Fennelly, MEMSIC Product Marketing Manager. “The 624x family gives ...a choice that works well in these high-vibration environments, and is the only accelerometer with these unique vibration-filtering properties.”


The 624x Family uses MEMSIC’s proprietary thermal accelerometer technology that utilizes heated gas molecules to sense acceleration instead of a mechanical beam structure, the transducer exhibits a natural low-pass frequency response with virtually no mechanical resonance and extremely high accuracy over a range of temperatures. This suits the devices to harsh and/or high vibration environments, where competing sensor solutions can exhibit false readings or other errors due to resonance.


The MXD6240 and MXD6241AU are autonomous inclination sensors with 8 built-in, pin-programmable tip-over angle thresholds from 40 to 70 degrees making them ideal for tip-over applications where no microcontroller is available. If the device orientation with respect to vertical exceeds the programmed threshold angle, the digital output changes state to alert the system to a tip-over or fall-down event. In addition to the transducer’s inherent low-pass response, an internal anti-vibration filter provides >45 dB attenuation above 25 Hz, and >60 dB attenuation above 50 Hz, setting it apart from all other tip-over sensors in the market.


The MXC6244AU and MXC6245XU are complete 2 axis I ²C interface accelerometers each with 1 mg of resolution. The MXC6244AU is ±8g full scale range device. It includes the internal anti-vibration filter and the 8 angle thresholds. They are programmable through the I ²C interface.


The MXC6245XU