HFBR-4663 Agilent(Hewlett-Packard), HFBR-4663 Datasheet - Page 12

• Manufacturer Part Number: HFBR-4663
• Description: Single Chip 10BASE-FL Transceiver
• Manufacturer: Agilent(Hewlett-Packard)

1. SQE Test: The FOIRL
standard did not include the
option of attaching a fiber
transceiver to a DTE. Adding the
SQE test to 10BASE-FL enables a
10BASE-FL transceiver to attach
to a DTE.
2. 0 to at Least 2 Km Distance:
The FOIRL standard specifies a 1
km distance while 10BASE-FL
specifies 2 km. The additional 1
km distance for 10BASE-FL
comes from an increased flux
budget for the cable of 3.5 dB.
This 3.5 dB increase came from
an increase of 2.5 dB sensitivity
for the receiver and a 1 dB
improvement for the transmitter.
The following table illustrates the
transmit and receive power
requirements for the two
standards. Note: FOIRL specifies
optical power in peak and
10BASE-FL specifies it in
average. Subtracting 3 dB from
peak will give the average. In the
table below the FOIRL
specifications were converted
from peak to average power.
3. MAU State Diagrams are
Different: The state diagrams for
10BASE-FL are similar to
10BASE-T, while the state
88
Transmit/Receive
FOIRL
10BASE-FL
Average Power
Transmitter
Receiver
Transmitter
Receiver
-12 dBm
-12 dBm
-12 dBm
-12 dBm
Min.
diagrams for FOIRL are slightly
different. The differences are in
the AUI loopback, and in the link
integrity function.
AUI Loopback - In 10BASE-FL
the DO to DI loopback is always
disabled during a collision, and
optical receive data is passed
through to DI. For FOIRL there
are some cases where loopback
continues (i.e. DO looped to DI)
during a collision, and others
where loopback is disabled
during a collision. 10BASE-FL is
identical to 10BASE-T in this
case. Please refer to the IEEE
standards for greater detail.
ORD input to input on DI
Output on DO to OTD_output
Collision Deassert to
SQE Deassert minimum
-32.5 dBm
Steady State Prop Delay
Start-Up Delay
-21 dBm
-30 dBm
-20 dBm
Steady State Prop Delay
Start-Up Delay
Parameter Differences
Max.
Timing
BER < 10
Conditions
BER < 10
-10
-9
Link Integrity - 10BASE-FL adds
an additional state to the Link
Integrity Test function that will
not allow an exit from the Low
Light State until both the
transmitter and receiver are idle.
In FOIRL, it is possible to exit
from the Low Light State while
still receiving data.
MAU Timing Differences - The
timing differences between
10BASE-FL and FOIRL relate to
propagation delays, start-up
delays, and collision deassert
delays. The following table
provides the details of these
parameters.
(BIT Times)
OTD - Optical Transmit Data
ORD - Optical Receive Data
DI, DO, CI - AU Interface Signals
FOIRL
4.5
0.5
3.5
0.5
3.5
(BIT Times)
10BASEFL
2
5
2
5
0