ASDL-3212-021 Avago Technologies US Inc., ASDL-3212-021 Datasheet - Page 15

• Manufacturer Part Number: ASDL-3212-021
• Description: Infrared Transceivers SFF MIR Front w/o Shield
• Manufacturer: Avago Technologies US Inc.

Specifications of ASDL-3212-021

• Wavelength: 870 nm, 875 nm
• Continual Data Transmission: 1.152 Mbit/s
• Transmission Distance: 50 cm
• Radiant Intensity: 80 mW/sr
• Half Intensity Angle Degrees: 15 deg
• Pulse Width: 1.5 us, 1.6 us
• Maximum Rise Time: 60 ns, 600 ns
• Maximum Fall Time: 60 ns, 600 ns
• Led Supply Voltage: 0 V to 6 V
• Maximum Forward Current: 60 mA
• Operating Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Dimensions: 7 mm x 2.73 mm x 1.64 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Appendix D: Window Design for ASDL-3212
Window Dimension
Figure D1. Window Design for ASDL-3212
To ensure IrDA compliance, some constraints on the
height and width of the window exist. The minimum
dimensions ensure that the IrDA cones angles are met
without vignetting. The maximum dimensions minimize
the e ects of stray light. The minimum size corresponds
to a cone angle of 300 and the maximum size corre-
sponds to a cone angle of 600.
In gure D1, X is the width of the window, Y is the height
of the window and Z is the distance from the ASDL-3212
to the back of the window. The distance from the center
of the LED lens to the center of the photodiode lens, K,
is 5.1mm. The equations for computing the window di-
mensions are as follows:
X = K + 2*(Z+D)*tanA
Y = 2*(Z+D)*tanA
15
IR Transparent Window
OPAQUE MATERIAL
Y
Z
D
A
IR Transparent Window
K
X
The above equations assume that the thickness of the
window is negligible compared to the distance of the
module from the back of the window (Z). If they are com-
parable, Z’ replaces Z in the above equation. Z’ is de ned
as
Z’=Z+t/n
where ‘t’ is the thickness of the window and ‘n’ is the re-
fractive index of the window material.
The depth of the LED image inside the ASDL-3212, D, is
4.32mm. ‘A’ is the required half angle for viewing. For IrDA
compliance, the minimum is 150 and the maximum is
300. Assuming the thickness of the window to be neg-
ligible, the equations result in the following table and
gures:
OPAQUE MATERIAL