HSDL-3020-021 Lite-On Electronics, HSDL-3020-021 Datasheet - Page 15

• Manufacturer Part Number: HSDL-3020-021
• Description: Infrared Transceivers IR Transceiver 4.0Mb/s
• Manufacturer: Lite-On Electronics

Specifications of HSDL-3020-021

• Wavelength: 875 nm
• Continual Data Transmission: 4 Mbit/s
• Transmission Distance: 50 cm
• Radiant Intensity: 10 mW/sr
• Half Intensity Angle Degrees: 30 deg to 60 deg
• Pulse Width: 4 us, 1.6 us
• Maximum Rise Time: 40 ns, 600 ns
• Maximum Fall Time: 40 ns, 600 ns
• Led Supply Voltage: 0 V to 6.5 V
• Maximum Forward Current: 190 mA
• Operating Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Dimensions: 10.4 mm x 2.95 mm x 2.5 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Appendix B: PCB Layout Suggestion
The effects of EMI and power supply noise can poten-
tially reduce the sensitivity of the receiver, resulting in
reduced link distance. The PCB layout played an impor-
tant role to obtain a good PSRR and EM immunity re-
sulting in good electrical performance. Things to note:
1. The ground plane should be continuous under the
2. The shield trace is a wide, low inductance trace back
3. IR and RC VLED can be connected to either unfil-
4. V
5. IOV
6. Preferably a multi-layered board should be used
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part, but should not extend under the shield trace.
to the system ground. CX1, CX2, CX3, CX4, CX5, CX6
and CX7 are optional supply filter capacitors; they
may be left out if a clean power supply is used.
tered or unregulated power supply. The bypass
capacitors should be connection before the current
limiting resistor R3 and R4 respectively. In a noisy
environment, including capacitor CX2 and CX7 can
enhance supply rejection. CX6 and CX3 that are
generally a ceramic capacitor of low inductance
providing a wide frequency response while CX2 and
CX4 are tantalum capacitor of big volume and fast
frequency response. The use of a tantalum capacitor
is more critical on the VLED line, which carries a high
current.
unregulated power supply. The Resistor, R1 together
with the capacitors, CX1 and CX2 acts as the low
pass filter.
the V
capacitor.
to provide sufficient ground plane. Use the layer
underneath and near the transceiver module as V
and sandwich that layer between ground connect-
ed board layers. The diagram below demonstrate an
example of a 4 layer board:
CC
pin can be connected to either unfiltered or
CC
CC
is connected to the ASIC voltage supply or
supply. The capacitor, CX5 acts as the bypass
CC
,
• Top Layer: Connect the metal shield and module
• Layer 2: Critical ground plane zone. 3 cm in all di-
• Layer 3: Keep data bus away from critical ground
• Bottom layer: Ground layer. Ground noise <75 mVp-
ground pin to bottom ground layer;
Place the bypass capacitors within 0.5cm from the
V
rection around the module. Connect to a clean,
noiseless ground node (eg bottom layer).
plane zone.
p. Should be separated from ground used by
noisy sources.
CC
and ground pin of the module.