hsdl3602 Avago Technologies, hsdl3602 Datasheet - Page 21

• Manufacturer Part Number: hsdl3602
• Description: Agilent Hsdl-3602 Irda Data 1.4 Compliant 4 Mb/s 3v Infrared Transceiver
• Manufacturer: Avago Technologies

Appendix C: Optical Port
Dimensions for HSDL-3602:
21
To ensure 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
sponds to a cone angle of 60
In the figure below, X is the
width of the window, Y is the
0
and the maximum size corre-
IR TRANSPARENT WINDOW
OPAQUE MATERIAL
º
.
Z
IR TRANSPARENT WINDOW
D
height of the window and Z is the
distance from the HSDL-3602 to
the back of the window. The dis-
tance from the center of the LED
lens to the center of the photo-
diode lens, K, is 7.08mm. The
equations for computing the win-
dow dimensions are as follows:
X = K + 2*(Z+D)*tanA
Y = 2*(Z+D)*tanA
The above equations assume that
the thickness of the window is
negligible compared to the dis-
tance of the module from the back
of the window (Z). If they are com-
A
X
K
parable, Z' replaces Z in the above
equation. Z' is defined as
Z'=Z+t/n
where ‘t’ is the thickness of the
window and ‘n’ is the refractive
index of the window material.
The depth of the LED image in-
side the HSDL-3602, D, is 8mm.
‘A’ is the required half angle for
viewing. For IrDA compliance,
the minimum is 15
maximum is 30
thickness of the window to be
negligible, the equations result in
the following tables and graphs:
OPAQUE MATERIAL
0
. Assuming the
0
and the