Transcript 1394b Design for Gigabit Optoelectronic Data

1394b Design for Gigabit
Optoelectronic Data
Communication
Group G9:
Tiffany Lovett, gte291r
Mareisha Winters, gte824t
Presented By:
Tornya Moore, gte668r
ECE 4006 C
Spring 2002
Objective

Design Considerations for VSCEL
 Link Budget Analysis
 Design of the VSCEL board
 Testing
 Future Testing
Design Considerations for the
VCSEL

Two candidates:
– Honeywell HFE4380-521
– Honeywell HFE4384-522
 Threshold current-minimum amount of current
needed for the VCSEL to emit light
 Slope Efficiency-tells how many amps it takes to
produce a given power output
Comparison of Two VCSEL
Candidates
HFE4380-521
HFE4384-522
Link Budget Analysis



Link budget analysis is the calculation and verification of
the operating characteristics of a fiber optic system
Prior to implementing or designing a fiber optic circuit, a
budget analysis is recommended to make certain the
system will work over the proposed link
For this project the purpose of the link budget is to
determine whether the transmitter and receiver system
provide sufficient current to drive the post amp.
Link Budget Analysis (Cont’d)
HFE4380-521HFE4384-522
Ith(m
A)
6
6
DCbiasoflaser(m
A)
7.2
7.2
SlopeEfficiency(m
W
/m
A)
0.04
0.15
M
odulationCurrentofTX(m
A)
30
30
RangeofPowerOutput(m
W
)
0.288-1.2 1.08-4.5
RangeofPowerOutput(w/ Loss)(m
W
)
0.144-0.6 0.54-2.25
ResponsivityofLaserm
atePD(A/W
)
0.4
0.4
ResponsivityofHam
am
atsuPD(A/W
)
0.47
0.47
RangeofCurrentfromLaserm
atePD(uA) 57.6-240
216-900
RangeofCurrentfromHam
am
atsuPD(uA) 67.7-282 253.8-1057.5
Design of the VCSEL Board



In order to minimize reflections the VCSEL circuit had to
have a total resistance of 50
A surface mount resistor of 25 was placed in series with
the VCSEL. Which has a typical resistance of 25
A DC bias T (2k resistor in series with the 5V power
supply) was connected to the circuit to allow connect to the
AC coupled GTS 1250 pattern generator
Design of the VCSEL Board
(cont’d)

Once all of the components were gathered
they were mounted on the board and
soldered onto the board.
Testing

The two pieces of equipment that will be used to verify the
functionality of the components are the Tektronix GTS
1250 pattern generator and Tektronix 7000 Series
Oscilloscope.
Testing (cont’d)




Initially tested the Agilent opto-electronic board from the
previous semester to generate an eye diagram
GTS 1250 was connected to the transmitter portion of the
board,the oscilloscope was connected to the receiver
portion, and a fiber cable was used to loop the receiver and
transmitter together
Tested the VCSEL board by connecting it to the GTS 1250
and then to the Agilent board
Tried to test the VCSEL board with the MAXIM
transmitter board but no diagram appeared
Testing (cont’d)

Block diagram of test setup for VCSEL
Testing (cont’d)

Eye diagram of Agilent board
Testing (cont’d)

Eye diagram of VSCEL board
Future Testing



To test the VCSEL board with the MAXIM transmitter
board
To implement the design for the photodetector circuit
To design VCSEL and photodetector boads using
SuperPCB layout package.