Capacitance Measurement/Comparator IC

[strahd_von_zarovich]

Hi everyone,
I am trying to find the IC in the picture. It is used in a capacitive accelerometer module. Sensor part consists of 2 capacitors, and their common plate is ground. When the module is under acceleration one capacitance decreases while the other one increases. Capacitors' plates(not the common ground one) are connected directly to the IC and I know IC has internal excitation source which has a frequency of ~450kHz~500kHz. And most probably IC's output is analog signal.

Have you seen such an IC? Either it compares 2 capacitances, or it has 2 inputs and 2 outputs I don't know. In addition, it is fairly sensitive device which can measure pF changes.
Device marking on IC was intentionally erased.

Thanks in advance.

 

[barry]

Analog Devices makes a number of accelerometer devices. Perhaps it’s one of those.

But why do you ask? Are you trying to reverse engineer (steal) the design?

 

[strahd_von_zarovich]

Analog Devices makes a number of accelerometer devices. Perhaps it’s one of those.

But why do you ask? Are you trying to reverse engineer (steal) the design?

Dear Barry,
Thank you for your answer. I don't think you can make an accelerometer without a sensor and I am not looking for accelerometer device. In other words, it doesn't really matter the real IC's part#. Any IC which can make low capacitance measurement and provides analog output would be sufficient too.

 

[barry]

Dear Barry,
Thank you for your answer. I don't think you can make an accelerometer without a sensor and I am not looking for accelerometer device. In other words, it doesn't really matter the real IC's part#. Any IC which can make low capacitance measurement and provides analog output would be sufficient too.

So you're looking for a capacitance measurement chip? Try an internet search for "capacitance measurement chip". That's what I did: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7745_7746.pdf

Here's another: https://www.analog-micro.com/en/products/ics/cuconverter/cav444/

 

[KlausST]

Hi,

This is not pointed to the OP only, but to everyone who uploads photos.

Again I want to remind to keep on forum rules which says:
"Also format your image attachments properly, use an image resolution that is easily readable, not too big or too small and use gif, png, or jpeg extension to reduce the size of the file."

It really not hard nor difficult to do. Usually a 1024 pixel wide photo is sufficient to show all details:

Format:
Photos (images with many different colors) --> use JPG format. A color quality of 30% often is sufficient.
For diagrams, screenshots of textext ... and so on --> use PNG format. It privides best quality with low file size.

Often I read: My PC / Laptop/ cellular phone is unable to reduce file size.
Honestly every cheap cellular phone / camera I did use has a setup.
PC (different OS) .. have simple photo editing software.

Or use some online tool like: https://www.resizepixel.com/
* upload your photo
* convert to JPG (in this case)
* resize for 1024 pixel width
* compress to 100kBytes
* download.

The result is this: 4,784 kBytes PNG --> 96 kBytes JPG

It´s less than 2% of file size. But still shows all important details.

Thanks for reading

Klaus