“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 prevent aliasing and recover the signal of interest,” said James Fennelly, Memsic Product Marketing Manager. “The 624x family gives customers a new cost effective 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 makes the devices extremely well suited 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 >45dB attenuation above 25Hz, and >60dB attenuation above 50Hz, setting it apart from all other tip-over sensors in the market.
The MXC6244AU and MXC6245XU are complete 2 axis I2C 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 I2C interface.
The MXC6245XU is a ±2g full scale range device and is targeted at cost sensitive applications not requiring the programmable anti-vibration filter or the 8 programmable tip-over angle thresholds. It offers 12 bits of resolution (1 mg) and has the same outstanding over temperature bias performance of typically 0.1 mg/C.
The 624x family offers a full range of functionality, features and performance to serve the diverse needs of different applications. The fully autonomous MXD6240/41 eliminate the need for a micro controller and can replace older mechanical pendulum solutions in motorcycles and off-road vehicles. The MXC6244AU can be used directly in Engine Control Units (ECUs) for the same application thereby allowing for the elimination of a separate tip-over module. For applications not requiring the enhanced vibration rejection or programmable angle thresholds, the MXC6245XU still delivers the excellent over temperature performance of the MXC6244AU at the lowest cost.