ST VL6180X - VL6180 X Typical Ranging Performance Analysis; VL6180 X Range Output vs. Target Distance

DocID026571 Rev 1 11/27
AN4545 Typical ranging output
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4 Typical ranging output
4.1 Range output
Figure 5 shows the typical ranging output from VL6180X for different targets
(b)
at different
distances.
Figure 5. Graph of range output vs. target distance. The test was performed in the
dark and with no cover glass.
The range output of VL6180X with each of the targets should be linear with range. There
could however be an offset error
(c)
. This error can be corrected by performing a manual
offset calibration, see Section 4.1.1.
Note: At <10mm the interaction between the target and VL6180X will prevent the range output
from reaching 0mm. This is due to a number of physical effects:
• Separation between VCSEL and return array
• Multiple reflections between target surface and VL6180X
• VCSEL output penetrating the target surface and scattering off the layers inside the
target
b. Munsell gray target.
c. See section 4 in the VL6180X dataset for the spec on offset error.