MEMS-based gyro sensor device for car navigation systems from Murata

Both devices are manufactured using proven and cost-effective production processes, to provide high reliability and superior performance at a low cost. From the OEM’s perspective, Murata’s MEV-50A-R gyro sensor is a compact, hermetically sealed, surface mount, ceramic device contained in a fully RoHS compliant package measuring just 10mm x 10mm, with a profile of 3.3mm. It is qualified to the –40oC to +85oC temperature range, making it ideal for automotive applications.

Murata’s gyro sensor uses Coriolis force principle of detecting angular velocity, whereby four masses are positioned between two driving beams. By flexing the driving beams, the masses are vibrated along the x-axis. Then, when angular velocity is applied, two detecting masses are vibrated along the y-axis, producing a rotation in the opposite direction to the Coriolis force.

This technique results in lower acceleration noise, when compared to acceleration techniques, as the capacitive variations are cancelled out. Further, the device uses digital signal compensation to deliver low offset drift over the temperature range.

Features include fast response, low driving voltage and low current consumption. Technical specifications over the –40oC to +85oC operating temperature range include: linearity error of –0.5% to +0.5% FS; output noise of 10mV peak to peak; start up drift of –0.4 to +0.4degrees/s from 1s to 5mins and –0.8 to +0.8degrees/s from 1s to 15min; and frequency response (frequency vs gain) of –4dB to –1dB with gain at 7Hz.