User Manual

Initial customer manufacturing calibration UM2039
6/26 DocID029105 Rev 1
2.2 Static Init
VL53L0X_StaticInit() function allows to load device settings specific for a given use
case.
2.3 Reference SPADs calibration
In order to optimize the dynamic of the system, the reference SPADs have to be calibrated.
This step is performed on the bare modules during Final Module Test at STMicroelectronics,
and the calibration data (SPAD numbers and type) are stored into the device NVM.
In case a cover glass is used on top of VL53L0X, the reference SPADs have to be re-
calibrated by the customer.
Reference SPAD calibration needs to be done only once during the initial manufacturing
calibration, calibration data should then be stored on the Host.
When calibration is performed and calibration data is available on the Host, the data can be
loaded without re-performing the calibration.
These functions can be called after VL53L0X_StaticInit(). It has to be done before Ref
Calibration, VL53L0X_PerformRefCalibration().
2.3.1 Reference SPADs calibration procedure
No particular conditions have to be used. The calibration does not require specific target or
lighting conditions.
The following procedure has to be performed:
• Call VL53L0X_PerformRefSpadManagement()
– This function outputs the number and type of reference SPADs to be used.
– At the end of this function, the reference SPADs number and type is programmed
in the device.
• Host has to store these 2 values. See Section 4.3.1 for loading calibration data from
Host.
Note: If a highly reflective target is covering the VL53L0X module during reference SPAD
calibration, too much signal will be received on the reference array and the calibration may
fail, reporting a ‘-50’ status code. In this case, user has to remove the target away from
device
2.4 Ref (temperature) calibration
Ref calibration is the calibration of two parameters (VHV and phase cal) which are
temperature dependent. These two parameters are used to set the device sensitivity.
Ref calibration allows the adjustment of the device sensitivity when temperature varies.
Ref calibration must be performed during initial manufacturing calibration, it should be
performed again when temperature varies more than 8degC compared to the initial
calibration temperature.
If temperature does not vary, the ref calibration data can be loaded without re-performing
the calibration procedure.