Datasheet

17
Window Design
To insure IrDA compliance, some
constraints on the height and width
of the window exist. The minimum
dimensions ensure that the IrDA cone
angles are met without vignetting.
The maximum dimensions minimize
the effects of stray light. The minimum
size corresponds to a cone angle of
30 degrees, the maximum, to a cone
angle of 60 degrees.
Minimum and Maximum Window Sizes
Dimensions are in mm.
Depth (Z) Y min. X min. Y max. X max.
0 1.70 6.80 3.66 8.76
1 2.23 7.33 4.82 9.92
2 2.77 7.87 5.97 11.07
3 3.31 8.41 7.12 12.22
4 3.84 8.94 8.28 13.38
5 4.38 9.48 9.43 14.53
6 4.91 10.01 10.59 15.69
7 5.45 10.55 11.74 16.84
8 5.99 11.09 12.90 18.00
9 6.52 11.62 14.05 19.15
10 7.06 12.16 15.21 20.31
Window Height Y vs. Module Depth Z
Window Width X vs. Module Depth Z
Y
X
Z
WINDOW HEIGHT Y – mm
16
MODULE DEPTH Z – mm
6
48
0
2
14
010
10
26
12
8
4
ACCEPTABLE
RANGE
60° CONE
30° CONE
WINDOW WIDTH X – mm
22
MODULE DEPTH Z – mm
12
48
6
8
20
010
16
26
18
14
10
ACCEPTABLE
RANGE
60° CONE
30° CONE
X is the width of the window, Y is the
height of the window, and Z is the
distance from the HSDL-3201 to the
back of the window. The distance
from the center of the LED lens to the
center of the photodiode lens is 5.1
mm. The equations for the size of the
window are as follows:
X = 5.1 +2(Z + D) tan q
Y = 2(Z + D) tan q
Where q is the required half
angle for viewing. For the IrDA
minimum, it is 15 degrees, for the IrDA
maximum it is 30 degrees. (D is the
depth of the LED image inside the
part, 3.17 mm). These equations result
in the following tables and graphs: