editor's blog
Subscribe Now

A Fully-Differential Accelerometer

Accelerometers are used for a wide variety of applications (which we’ll look at more specifically soon). Particularly demanding are automotive applications, not least because of the harsh conditions and huge amount of noise that they must tolerate. That noise can be electrical or simply “ambient vibration” that is not of interest.

Electrically, differential signaling is often used to reject common-mode noise. But one paper at ISSCC took the concept all the way back to the proof mass: a team from Robert Bosch split the proof mass, working then with what are nominally two identical half-masses. This sets up a differential signal flow from the get-go.

Of course, the masses aren’t going to be exactly the same; various differences are averaged out by swapping back and forth (to oversimplify). Chopping is also used to boost near-DC noise up away from the frequencies that matter, although the process does result in some noise being moved into the way instead of out of the way. In order to minimize the effect of this, they used a pseudo-random signal for chopping so that the energy of this noise is, to use their word, “smeared” across the spectrum, rendering it largely impotent.

You can find circuit details and results in the ISSCC proceedings, paper 22.1

Leave a Reply

featured blogs
Jan 17, 2020
I once met Steve Wozniak, or he once met me (it's hard to remember the nitty-gritty details)....
Jan 17, 2020
[From the last episode: We saw how virtual memory helps resolve the differences between where a compiler thinks things will go in memory and the real memories in a real system.] We'€™ve talked a lot about memory '€“ different kinds of memory, cache memory, heap memory, vi...
Jan 16, 2020
While Samtec started as a connector company with a focus on two-piece, pin-and-socket board stacking systems, High-Speed Board Stacking connectors and High-Speed Cable Assemblies now make up a significant portion of our sales. To support development in this area, in December ...
Jan 16, 2020
Betting on Hydrogen-Powered Cars On-demand DRC within P&R cuts closure time in half for MaxLinear Functional Safety Verification For AV SoC Designs Accelerated With Advanced Tools Automating the pain out of clock domain crossing verification Mentor unpacks LVS and LVL iss...

Featured Video

RedFit IDC SKEDD Connector

Sponsored by Wurth Electronics and Mouser Electronics

Why attach a header connector to your PCB when you really don’t need one? If you’re plugging a ribbon cable into your board, particularly for a limited-use function such as provisioning, diagnostics, or testing, it can be costly and clunky to add a header connector to your BOM, and introduce yet another component to pick and place. Wouldn’t it be great if you could plug directly into your board with no connector required on the PCB side? In this episode of Chalk Talk, Amelia Dalton chats with Ben Arden from Wurth Electronics about Redfit, a slick new connector solution that plugs directly into standard via holes on your PCB.

Click here for more information about Wurth Electronics REDFIT IDC SKEDD Connector