editor's blog
Subscribe Now

What Might Make an Accelerometer More Robust?

Last month STMicroelectronics announced a new accelerometer “engineered to withstand stresses of modern mobile life.” They see those stresses arising from increasingly thinner phones and the mechanical and thermal challenges they cause. They called out board bending as a particular challenge to the mechanical integrity of the works inside the accelerometer package.

So how do you improve the mechanical structure of the accelerometer to do this? First, it helps to realize that there are two structures in ST’s accelerometers. One operates in-plane and provides both x and y acceleration information. A separate structure is used for the out-of-plane z axis acceleration. On older models, these two structures were set side by side.

To illustrate how things might be improved, they made reference to stability in an airplane, even though the comparison can’t be taken too literally. If you want the smoothest ride in the plane, you sit in the middle, between the wings. Especially to the extent that the middle has the least stress and that stresses radiate out from that, there’s more disturbance (bumpiness) at the extremes – the wingtips and nose and tail – than in the middle.

It turns out that the z-axis accelerometer is the most sensitive, so improving it was a goal. So they moved it to the middle of the die layout rather than having it off on one side. And where would the x/y structure go if the z structure is hogging the middle? Symmetry is achieved by splitting the x/y structure and putting one half on either side of the center z structure. The two halves become the “wings.”

The other improvement was to double the number of anchoring points on the z structure from 2 to 4. This reduced the stresses on those points, making them less subject to failure.

You can find more details on the performance of this acceleromete

Leave a Reply

featured blogs
Mar 29, 2024
By Mark Williams, Sr Software Engineering Group Director Translator: Masaru Yasukawa 差動アンプはã1つの入力信号ではなく2つの入力信号間の差にゲインをé...
Mar 26, 2024
Learn how GPU acceleration impacts digital chip design implementation, expanding beyond chip simulation to fulfill compute demands of the RTL-to-GDSII process.The post Can GPUs Accelerate Digital Design Implementation? appeared first on Chip Design....
Mar 21, 2024
The awesome thing about these machines is that you are limited only by your imagination, and I've got a GREAT imagination....

featured video

We are Altera. We are for the innovators.

Sponsored by Intel

Today we embark on an exciting journey as we transition to Altera, an Intel Company. In a world of endless opportunities and challenges, we are here to provide the flexibility needed by our ecosystem of customers and partners to pioneer and accelerate innovation. As we leap into the future, we are committed to providing easy-to-design and deploy leadership programmable solutions to innovators to unlock extraordinary possibilities for everyone on the planet.

To learn more about Altera visit: http://intel.com/altera

featured chalk talk

Trends and Solutions for Next Generation Energy Storage Systems
Sponsored by Mouser Electronics and onsemi
Increased installations of DC ultra fast chargers, the rise of distributed grid systems, and a wider adoption of residential solar installations are making robust energy storage systems more important than ever before. In this episode of Chalk Talk, Amelia Dalton, Hunter Freberg and Prasad Paruchuri from onsemi examine trends in EV chargers, solar, and energy storage systems, the role that battery storage integration plays in energy storage systems, and how onsemi is promoting innovation in the world of energy storage systems.
Jan 29, 2024
8,727 views