Analog gyroscope solution

[AGall.1]

Hi everyone,

I'm wondering if there is a solution from ST for a analog gyroscope eventually on 3-axis for a crash-test micro device for test and measuring that I'm designing.

Basically I've found an old product from ST named LYPR540AH but it is obsolete now. Currently only a solution from analog devices seems available (ADXRS6XX family) and a solution from silicon sensing. Do you know if there is something available?

Thanks in advance

[Eleon BORLINI]

Hi @Community member​ , unfortunately ST has no analog gyroscope in the portfolio (there is only an accelerometer, the LIS344ALH). As a personal statement, I believe it is not so easy to manage an analog qyro (I mean, you have to give the stimulus, clear the noise and synchronize the sensing and the driving stimulus, with all the calibration steps to do outside the device...)

Btw, I believe that a digital device could anyway fit your application... which use case do you have in mind?

Regards

[AGall.1]

Hi @Eleon BORLINI​ ,

I'm looking for an analog solution because in the crash tests users need a miniature solution where they can sample data with an external acquisition board.

The usual size for the enclosure is 15mmx15mm so I cannot use digital solution because I have no space for other components.

I believe that having an analog solution, as ST had in the past, open this kind of scenario where a pure analog gyroscope can be used.

Anyway I'll try to find solution from other manufacturing.

Thanks

[AGall.1]

Why the L3G462A is no longer available?

[Eleon BORLINI]

This is unfortunately a nrnd product, basically for the reason I added before: a digital gyroscope is more accurate or, better, can be more accurately calibrated than an analog part. Btw, I understand your design-continuity reason: you could try to check with distributors (Farnell, Digikey, Mouser), if they have enough stock of L3G462A components. However, I have a question: on your 15mmx15mm pcb / system, do you mount the analog gyro stand-alone (with no other component) or are you able to mount the entire acquisition system? Regards

[AGall.1]

@Eleon BORLINI​ I cannot base a product on a nrnd component like the L3G462A as you can understand.

Sure, on my 15mm x 15mm system (the external enclosure dimensions I mean) I can mount only the supply section and the gyro stand-alone. Not enough space for a digital solution.

Basically all the applications like auto safety crash testing, aerospace testing, pedestrian impact, rollover testing, motorsports, robotic system, etc... require an ultra small device where the user set all the analogic acquisition with an external DAQ.

[Eleon BORLINI]

Understood... well, auto safety requires more than L3G462A device, indeed ;) And I agree with you that mechanical system for the motion event detection in those applications are traditionally analogical (especially accelerometers, but gyroscopes too). I can say you that ST has developed inertial systems for the automotive and industrial markets, but since I cannot go further in my being useful, I suggest you to contact an STMicroelectronics sales office and representatives from your geographical region (here the LINK). Regards

[AGall.1]

Ok, thanks.

But onestly I cannot understand how they can produce this kind of device

https://www.dytran.com/Model-7576A1-Analog-6DOF-Sensor-P3705/

for example without using an analogic chip.

How do they reach this miniaturized level?

On which IMU chip is based?

[Eleon BORLINI]

Well, I'm not sure I caught your comment... an analogical MEMS device is typically smaller than a digital one, because it is only equipped by the mechanical MEMS and not by the digital part of the ASIC (btw, ST chips are much smaller than 15mm x 15mm). But the overall dimension of the application module basically depends on the acquisition system... it is not difficult to create a small module if the acquisition processor is far from the sensing module, connected with a long cable (this is the case of the digital but even more the case of the analog product you linked me), and the acquisition systems for an analog signal is typically much bigger than the analogical device one (you need to condition the signal in a more detailed way, with amplifiers, ADC, any physical filters, and so on). Regards

[AGall.1]

@Eleon BORLINI​ do you have the L3G462A in stock somewhere?

For example 20 pcs?

Thanks

[Eleon BORLINI]

I'm afraid we have no more samples in our store, but I'll do a check when we come back to our labs and in case I'll give you a positive feedback. Please note however that, in case we had some samples remaining, the product is nevertheless NRND and should not be used for future projects. Regards