Post on 09-Aug-2020
transcript
Eval-FB2M5LRR
Ethernet LC Evaluation Kit
User Guide
Eval-FB2M5LRR Revision A
1
OVERVIEW
The Eval-FB2M5LRR evaluation kit enables
evaluation of the Firecomms LC transceiver for
plastic optic fibre (POF) and large core glass
fibre (200, 400 um PCS). The kit includes a single
LC transceiver pre-mounted onto a simple PCB
that allows easy application of DC power via
standard 2 mm diameter DC jacks. Data inputs
(TD +/-) and data outputs (RD +/-) are connected
via standard screw terminal SMA connectors. A
single loop-back POF cable with LC plug is also
included.
For particular POF or PCS lengths and
assemblies please contact Firecomms
Applications support directly.
1
1 2
1 µ H
IC
IC
2
3
4
5
6
7
8
9
1 0
1 1
1 0 0 n F
1 µ H
1 0 0 n F
1 0 0 n F
1 0 0 n F
1 0 0 Ω
1 0 0 n F
1 0 0 n F
R D +
R D -
R S S I
V c c
V c c
T D +
T D -
1 0 µ F
1 0 µ F
1 0 µ F
1 0 µ F
1 0 k ΩR L
FIGURE 1
Recommended circuit layout for the LC transceiver
Eval-FB2M5LRR
Ethernet LC Evaluation Kit
User Guide
Eval-FB2M5LRR Revision A
2
EVALUATION KIT CONTENTS
The Evaluation Kit contains the following:
1. Evaluation PCB
2. FB2M5LRR mounted onto the evaluation PCB
3. POF cable with loop back LC plug (1 m, 0.5 NA, 2.2 mm jacket simplex POF)
4. FB2M5LRR Datasheet
INITIAL SETUP
1. Connect GND of a DC power supply to the ground points of the PCB (black terminals).
2. Connect 3.3 V to each of the Tx and Rx VCC jacks (red terminals).
3. To monitor RSSI, connect a multimeter or oscilloscope channel set to 1 MΩ input and measure the
voltage VRSSI. VRSSI is set by a 10 kΩ resistor. See datasheet for graph of optical power against VRSSI.
4. Connect suitable pattern generator differential data signals via SMA cables to the TD +/- data pins.
5. Connect the RD +/- data pins to a suitable high-speed oscilloscope using 50 Ω termination and high-
speed coax, SMA terminated cables.
6. For a loop-back cable test, connect the provided LC loop-back cable assembly into the LC
connector. This connects the Tx back to the Rx over 1m of Step-Index POF.
FIGURE 2
Setup of the FB2M5LRR Evaluation PCB
Data Input
Data Output Rx Ground Rx DC Power
POF Cable
LC Transceiver
Tx DC Power Tx Ground