APDS-9003-021 Avago Technologies US Inc., APDS-9003-021 Datasheet - Page 10

• Manufacturer Part Number: APDS-9003-021
• Description: MINIATURE SURFACE-MOUNT AMBIENT LIGHT PHOTO SENSOR
• Manufacturer: Avago Technologies US Inc.

Specifications of APDS-9003-021

• Package: 6Chip LED

Figure 5(a): Window Size Determination for Flat Window
Figure 5(b): Window Design of Flat Window with Light Guide
Appendix B: Optical Window Design for APDS-9003
2.0
To ensure that the performance of the APDS-9003 will
not be affected by improper window design, there are
some constraints on the dimensions and design of the
window. There is a constraint on the minimum size of the
window, which is placed in front of the photo light sensor,
so that it will not affect the angular response of the APDS-
9003. This minimum dimension that is recommended
will ensure at least a ±35° light reception cone.
If a smaller window is required, a light pipe or light guide
can be used. A light pipe or light guide is a cylindrical
piece of transparent plastic, which makes use of total
internal reflection to focus the light.
The thickness of the window should be kept as minimum
as possible because there is a loss of power in every
optical window of about 8% due to reflection (4% on
each side) and an additional loss of energy in the plastic
material.
Figure 5a and 5b illustrate the two types of window that
we have recommended which could either be a flat
window or a flat window with light pipe.
10
Optical Window Dimensions
Table 1 and Fgure 6 below show the recommended
dimensions of the window. These dimension values are
based on a window thickness of 1.0mm with a refractive
index 1.585.
Figure 6: Recommended Window Dimensions
WD:
& APDS-9003
D1: Window Diameter
T:
L:
D2: Light Pipe Diameter
Z:
WD
Light Receving Area
Thickness
Length of Light Pipe
Distance between window rear panel and APDS-
9003
Working Distance between window front panel
D1
APDS-9003
L
Z
T
Top View
D2 D1