New generation of high performance MEMS gyros prepare to tackle harsh environments

March 09, 2011 // By Paul Buckley
In this news analysis article EE Times Europe Analog's editor, Paul Buckley, discusses the development of the new iMEMS gyroscopes launched by Analog Devices Inc., with Wayne Meyer, ADI's Marketing & Applications Manager MEMS and Sensor Technologies Division.

Earlier in the month Analog Devices, Inc (ADI) unveiled three new high-performance, low-power iMEMS gyroscopes with analog output specifically for angular rate (rotational) sensing in harsh environments. 

The ADXRS642, ADXRS646, and ADXRS649 incorporate ADI's advanced, differential quad-sensor technology, which rejects the influence of linear acceleration and vibration to enable these new MEMS gyros to offer exceptionally accurate and reliable rate sensing even where severe shock and vibration are present.

The new MEMS gyros offer linear acceleration sensitivities as low as 0.015°/s/g which compares with 0.1°/s/g which is currently offered by the leading alternative MEMS gyros.

The ADXRS64x series is claiming 10 times lower power consumption at 3.5 mA which compares with other MEMS gyros that consume as much as 60 mA. The device also benefits from much faster start- up times, as fast as 3 ms.

EE Times Europe:  So what are the design engineers looking for in these high performance applications? 

Meyer: The three top things that design engineers look for are:

1)  Bias stability, or what some people call drift, because all gyros drift over time.  The better the gyro the less the drift over time and also the more expensive the gyro. 

2)  The vibration and shock immunity. How resilient is the product for giving you a true reading when it is in an environment that's not just nice and clean and stable.   

3)  Noise because people want a low noise floor in order for them to get an accurate reading and not be interfered with. 

Those are huge and if you look at all the consumer gyros you will see that those stats are not specified and the reason they don't talk about them is that they would look very, very poor in that aspect.      

The customers that are looking for high performance are going to be looking for those numbers. If they don't see them they will go elsewhere. When you look at these new