MEV-50C-R
Murata has launched a MEMS rate sensor (gyro) which features &lsquoexcellent&rsquo performance acteristics for the automotive market. The MEV-50C-R supports accurate dead-reckoning performance for car navigation devices, and is also aimed at GPS modules, satellite antennas and other applications such as toys, including for example a high-performance radio-control helicopter.
The sensor features the second-generation of Murata&rsquos technology &ndash the first generation was used in Murata&rsquos famous bicycle-riding robots, Murata boy and the unicycle-riding Murata Girl.
High temperature drift performance makes signal processing easy &ndash there is no need to adjust for temperature drift in software. Temperature drift across the entire operating range, -40C to 85C, is just 0.6 deg/s. Materials used in the construction of the rate sensor help to ensure the stable temperature performance of the device. Single-crystal silicon is used for the core MEMS vibrator, while the MEMS element is composed of silicon and pyrex glass, which have very similar temperature expansion coefficients, increasing stability.
Another key factor for rate sensors used in car navigation systems is the start-up drift. It typically takes several minutes after the system is switched on for a GPS signal to be acquired, so dead-reckoning is commonly used during this time. The MEV-50C-R exhibits particularly impressive start-up drift just 0.1 deg/s between 0.5s and 5 minutes after start-up.
High linearity (0.5 across the operating range of angular velocity) and low cross-axis sensitivity (+/-5) make it possible to follow even the most winding roads as the sensor output follows the change of angular rate precisely.
The MEMS element uses anodic bonding creating a seal which achieves much better performance than the current industry standard of 10-9 Pa m3/s. The seal did not change its efficiency during air tank/heat shock tests with 2000 cycles of -55C to +125C (30 min/30 min). This high level of seal allows Murata&rsquos MEMS technology to be applied under harsh conditions such as automotive.
The MEV-50C-R measures 10mm x 6.2mm x 2.9mm and weighs just 0.3g (maximum). Maximum angular velocity is +/-70deg/s. The sensor&rsquos &lsquounique&rsquo ladder structure m