Optical filtering

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2.2.2

Air gap

The distance between the VL6180X and the cover glass is referred to as the air gap. As the

air gap increases, the amount of cross talk also increases. The cross talk compensation

defines the gain applied in the system to compensate for the cross talk.

Figure 4. Cross talk variation

For optimum ranging performance, the crosstalk should be kept low. Figure 4 shows the

typical cross talk seen when used with a cover glass with oval aperture.

The variation in the amount of cross talk compensation required can be important if the air

gap is likely to change throughout the lifetime of the system.