LPS Pressure-sensor: model differences and part naming scheme

[JHenn.1]

I am looking for "cavity"-type pressure sensors like the LPS27 or LPS33 but I am having a hard time finding out what the differences between the models are. For the stm32f series the online documentation includes a great comparison chart of the different models and I was expecting to find something similar for the pressure sensors.

So far I got:

• LPS22, LPS25, LPS35: normal, "non-cavity" types (not interesting for me)
• LPS27HHW: 2.7x2.7mm, 200Hz, low noise, CCLGA10
• LPS33: 3.3x3.3mm, 75 Hz
  • LPS33K: low noise, CCLGA4 (only I2C, no SPI)
  • LPS33HW: low noise, CCLGA10
  • LPS33W: higher noise, CCLGA10

The price (digikey) for LPS27 and LPS33K is similar, the LPS33HW is a bit cheaper and LPS33W is the cheapest.

Whats the point of the LPS33K, the LPS27 is smaller and better and costs the same?

Are LPS33HW and *W just "budged" options or do they offer any benefits that I missed?

Knowing the naming intentions behind "K", "W", "H" and "HH" would probably help understand the differences better. Is that information somewhere available?

Best regards

[Eleon BORLINI]

Hi @JHenn.1​ , you can refer to the pressure sensor product selector on corporate st.com website, where all the details are listed.

>> Whats the point of the LPS33K, the LPS27 is smaller and better and costs the same?

Thanks to its potted gel package (more expensive), the LPS33K device has a high overpressure capability: 20x full scale.

>> Are LPS33HW and *W just "budged" options or do they offer any benefits that I missed?

They differ from the package.

>> Knowing the naming intentions behind "K", "W", "H" and "HH" would probably help understand the differences better. Is that information somewhere available?

I suggest you to check the Quick reference guide, where the meaning of the part number letters are described (H = high performance, W = "waterproof").

you can btw also download the ST Sensors Finder app from your smartphone store and select the application (and the related sensor) that best fits your need

Regards

[JHenn.1]

Thank you for your reply.

About the potted gel package: the datasheets show that all sensors (LPS27and LPS33W/HW/K) have a potted gel package. All LPS33 (K,W and HW) are rated to 20x overpressure capability. So I guess the difference is that the LPS27 also has a potted gel package, but a different one that is less protective.

I still would really like to understand the intention behind using a CCLGA4 package for the LPS33K. The sensor has the exactly same physical size as the LPS33W/HW but uses less pins which removes the option to use SPI.