ASDL-3023-021 Avago Technologies US Inc., ASDL-3023-021 Datasheet - Page 22

• Manufacturer Part Number: ASDL-3023-021
• Description: Infrared Transceivers SFF FIR+RC Front w/o Shield
• Manufacturer: Avago Technologies US Inc.

Specifications of ASDL-3023-021

• Wavelength: 885 nm, 875 nm
• Continual Data Transmission: 4 Mbit/s
• Transmission Distance: 30 cm
• Radiant Intensity: 50 mW/sr
• Half Intensity Angle Degrees: 15 deg
• Pulse Width: 4 us, 1.6 us
• Maximum Rise Time: 60 ns, 600 ns
• Maximum Fall Time: 60 ns, 600 ns
• Led Supply Voltage: - 0.3 V to 6 V
• Operating Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Dimensions: 7.5 mm x 2.75 mm x 1.75 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Window Material
Almost any plastic material will work as a window
material. Polycarbonate is recommended. The surface
finish of the plastic should be smooth, without any
texture. An IR filter dye may be used in the window to
make it look black to the eye, but the total optical loss
of the window should be 10% or less for best optical
performance. Light loss should be measured at 875 nm.
The recommended plastic materials for use as a cosmetic
window are available from General Electric Plastics.
Recommended Plastic Materials:
Note: 920A and 940A are more flame retardant than 141.
Recommended Dye: Violet #21051
(IR transmissant above 625mm)
Flat Window, (First Choice)

Material #
Lexan 4
Lexan 90A
Lexan 940A
Light Transmission
88%
85%
85%
Haze
%
%
%
Curved Front and Back, (Second Choice)
Refractive Index
.586
.586
.586
Shape of the Window
From an optics standpoint, the window should be flat.
This ensures that the window will not alter either the
radiation pattern of the LED, or the receive pattern of the
photodiode. If the window must be curved for mechani-
cal or industrial design reasons, place the same curve on
the backside of the window that has an identical radius as
the front side. While this will not completely eliminate the
lens effect of the front curved surface, it will significantly
reduce the effects. The amount of change in the radiation
pattern is dependent upon the material chosen for the
window, the radius of the front and back curves, and the
distance from the back surface to the transceiver. Once
these items are known, a lens design can be made which
will eliminate the effect of the front surface curve. The
following drawings show the effects of a curved window
on the radiation pattern. In all cases, the center thickness
of the window is 1.5 mm, the window is made of polycar-
bonate plastic, and the distance from the transceiver to
the back surface of the window is 3 mm.
Curved Front, Flat Back, (Do not use)