editor's blog
Subscribe Now

Sensor Conditioning Options

One of the big challenges of MEMS sensor development is the fact that the raw sensor signals need to be conditioned before being read and acted on. This is done in the “ASIC” that ordinarily accompanies the sensor, typically on a separate die and co-packaged with the sensor (unless done on the same chip in a CMOS-friendly MEMS process). A well-known sensor design challenge is the fact that the ASIC has to be designed alongside the sensor, but that, until tools become more accurate, the actual sensor output isn’t known until the sensor has been built (and perhaps after a couple of design spins); that makes it very hard to co-design the ASIC and build it in parallel with the sensor.

Sensors are inherently analog devices, so it takes an analog front end to condition those signals – or at least convert them to digital for further digital processing. If you have a plain sensor with analog outputs and no encapsulated ASIC, then you have to build your own analog conditioning circuit.

Two companies are providing programmable conditioning circuits to avoid both the serial ASIC design issue and the need to build a discrete analog conditioning circuit. They allow a system designer to adjust the tuning of the conditioning network on the target board. This obviously has benefits over doing the manual circuit by hand, and it also means that any effect that the mounting or location of the sensor might have on the sensor output can be factored into the conditioning. Of course, as compared to a sensor with a co-packaged ASIC, it’s an additional chip and work.

Both Si-Ware and Renesas have such chips, Renesas’ recently announced. Si-Ware announced early last summer an actual development platform, the SWS61111, that features their own ASIC chip, the SWS1110. There’s also an FPGA on the board; the system allows a designer to determine the optimal conditioning configuration and then burn it into the ASIC, which has e-fuses for storing a one-time-programmable (OTP) setting.

Meanwhile, Renesas has announced its Smart Analog configurable conditioning circuit. It comes with its own graphic tool to enable tuning without requiring that you be an analog expert. There are two versions: one that it is intended to be paired with a microcontroller, and one that has the microcontroller co-packaged with the Smart Analog part. In both cases, the Smart Analog settings are stored in the microcontroller’s NVM.

You can find more in the earlier Si-Ware release or the more recent Renesas release.

Leave a Reply

featured blogs
Sep 21, 2020
Technology is changing the strategies we use to do things - oh so fast that 2010 seems like a distant past- within many spaces -- including the way we do our current topic of interest - Timing... [[ Click on the title to access the full blog on the Cadence Community site. ]]...
Sep 21, 2020
Semicon, the world’s largest semiconductor conference and exhibition, is September 23-25 in Taiwan. Like most shows of its size and caliber, Semicon boasts a long and illustrious list of exhibitors (500+), and countless forums, symposiums, and workshops. Of course Semic...
Sep 18, 2020
[From the last episode: We put the various pieces of a memory together to show the whole thing.] Before we finally turn our memory discussion into an AI discussion, let'€™s take on one annoying little detail that I'€™ve referred to a few times, but have kept putting off. ...
Sep 16, 2020
In addition to the Great Highland (Scottish) bagpipes, the Uilleann (Irish) bagpipes, and the Northumbrian (English) bagpipes, there are myriad other offerings spanning the globe....

Featured Video

Latency-Optimized PAM-4 Architecture for Next-Generation PCIe

Sponsored by Synopsys

This video presentation briefly describes how DesignWare® IP for PCIe® 5.0 is minimizing risk and accelerating time to market, and what Synopsys is doing to help designers prepare for next-generation PAM-4 PCIe 6.0 designs.

Click here for more information about DesignWare IP Solutions for PCI Express

Featured Paper

Designing highly efficient, powerful and fast EV charging stations

Sponsored by Texas Instruments

Scaling the necessary power for fast EV charging stations can be challenging. One solution is to use modular power converters stacked in parallel.

Learn More in our technical article

Featured Chalk Talk

Passive Component Solutions for Automotive Safety Electronics

Sponsored by Mouser Electronics and AVX

In today’s demanding automotive safety applications, choosing high-quality passives with the right performance properties can make the difference between success and catastrophic failure. With issues like power quality, EMI suppression, circuit protection, and antennas, getting the right passives is critical. In this episode of Chalk Talk, Amelia Dalton chats with Daniel West of AVX about how to choose the right passives for safety-critical automotive applications.

Click here for more information about AVX Solutions for Automotive Safety Electronics