Skip to main content
Associate II
May 2, 2025
Solved

vl53L4CD coverglass distance

  • May 2, 2025
  • 2 replies
  • 438 views

Hi!

I have a question about calibrating vl53L4CD and using a coverglass. I am doing experiments with a sample flat panel from Gilysmo, and I have noticed that if the panel is 2-3mm from the sensor, the calibration doesn't compensate for it. It looks like it just ranges to the glass and that's it. 

Is that normal? What is the maximum distance the glass should be from the sensor? Or perhaps I am doing something wrong?

Thanks!

Best answer by John E KVAM

Your experiments sound like you got the expected result.

Read the article:

https://community.st.com/t5/mems-and-sensors/time-of-flight-cover-glass/ta-p/49259 

And it will tell you that the first consideration is glass quality.

But the second most important consideration is air gap. The distance between the sensor and the coverglass.

That glass you have is fine. So, reduce the air gap as much as you can and you should be all set.

There is a crosstalk free glass, but it sits right down on top of the sensor and is glued to your PCB. 

Gilysmo sells that as well.

- john 

 

2 replies

John E KVAM
John E KVAMBest answer
ST Employee
May 2, 2025

Your experiments sound like you got the expected result.

Read the article:

https://community.st.com/t5/mems-and-sensors/time-of-flight-cover-glass/ta-p/49259 

And it will tell you that the first consideration is glass quality.

But the second most important consideration is air gap. The distance between the sensor and the coverglass.

That glass you have is fine. So, reduce the air gap as much as you can and you should be all set.

There is a crosstalk free glass, but it sits right down on top of the sensor and is glued to your PCB. 

Gilysmo sells that as well.

- john 

 

Associate II
May 5, 2025

Many thanks for the pointer! I had not found the topic in question before - I should have searched more thoroughly.

Cheers