146
11. These optical power values are 
measured with the following 
conditions:
• The Beginning of Life (BOL) to 
the End of Life (EOL) optical 
power degradation is typically 1.5 
dB per the industry convention for 
long wavelength LEDs. The actual 
degradation observed in HewlettPackard’s 1300 nm LED products 
is < 1 dB, as specified in this data 
sheet.
• Over the specified operating 
voltage and temperature ranges.
• With HALT Line State, (12.5 MHz 
square-wave), input signal.
• At the end of one meter of noted 
optical fiber with cladding modes 
removed.
The average power value can be 
converted to a peak power value by 
adding 3 dB. Higher output optical 
power transmitters are available on 
special request.
12. The same comments of note 11 
apply except that industry convention for short wavelength LED (800 
nm) BOL to EOL aging is 3 dB. This 
value for Output Optical Power will 
provide a minimum of a 6 dB optical 
power budget at the EOL, which 
will provide at least 500 meter link 
lengths with margin left over for 
overcoming normal passive losses, 
such as in line connectors, in the 
cable plant. The actual degradation 
observed in normal commercial 
environments will be considerably 
less than this amount with HewlettPackard’s 800 nm LED products. 
Please consult with your local HP 
sales representative for further 
details.
13. The Extinction Ratio is a measure of 
the modulation depth of the optical 
signal. The data “0” output optical 
power is compared to the data “1” 
peak output optical power and 
expressed as a percentage. With the 
transmitter driven by a HALT Line 
State (12.5 MHz square-wave) 
signal, the average optical power is 
measured. The data “1” peak power 
is then calculated by adding 3 dB to 
the measured average optical power. 
The data “0” output optical power is 
found by measuring the optical 
power when the transmitter is 
driven by a logic “0” input. The 
extinction ratio is the ratio of the 
optical power at the “0” level 
compared to the optical power at the 
“1” level expressed as a percentage
or in decibels.
14. The transmitter provides 
compliance with the need for 
Transmit_Disable commands from 
the FDDI SMT layer by providing 
an Output Optical Power level of 
< -45 dBm average in response to a 
logic “0” input. This specification 
applies to either 62.5/125 µm or 
50/125 µm fiber cables.
15. This parameter complies with the 
FDDI PMD requirements for the 
tradeoffs between center wavelength, spectral width, and rise/fall 
times shown in Figure 9.
16. This parameter complies with the 
optical pulse envelope from the 
FDDI PMD shown in Figure 10. The 
optical rise and fall times are 
measured from 10% to 90% when 
the transmitter is driven by the 
FDDI HALT Line State (12.5 MHz 
square-wave) input signal.
16a. The optical rise and fall times are
measured from 10% to 90% when 
the transmitter is driven by the 
FDDI HALT Line State (12.5 MHz 
square-wave) input signal.
17. Duty Cycle Distortion contributed 
by the transmitter is measured at a 
50% threshold using an IDLE Line 
State, 125 MBd (62.5 MHz squarewave), input signal. See Application 
Information - Transceiver Jitter 
Performance Section of this data 
sheet for further details.
18. Data Dependent Jitter contributed 
by the transmitter is specified with 
the FDDI test pattern described in 
FDDI PMD Annex A.5. See Application Information - Transceiver Jitter 
Performance Section of this data 
sheet for further details.
19. Random Jitter contributed by the 
transmitter is specified with an 
IDLE Line State, 125 MBd (62.5 
MHz square-wave), input signal. 
See Application Information Transceiver Jitter Performance 
Section of this data sheet for further 
details.
20. This specification is intended to 
indicate the performance of the 
receiver section of the transceiver 
when Input Optical Power signal 
characteristics are present per the 
following definitions. The Input 
Optical Power dynamic range from 
the minimum level (with a window 
time-width) to the maximum level is 
the range over which the receiver is 
guaranteed to provide output data 
with a Bit Error Ratio (BER) better
than or equal to 2.5 x 10
-10
.
• At the Beginning of Life (BOL)
• Over the specified operating 
temperature and voltage ranges
• Input symbol pattern is the FDDI 
test pattern defined in FDDI PMD 
Annex A.5 with 4B/5B NRZI 
encoded data that contains a duty 
cycle base-line wander effect of 
50 kHz. This sequence causes a 
near worst case condition for 
inter-symbol interference.
• Receiver data window time-width 
is 2.13 ns or greater and centered 
at mid-symbol. This worst case 
window time-width is the 
minimum allowed eye-opening 
presented to the FDDI PHY 
PM._Data indication input (PHY 
input) per the example in FDDI 
PMD Annex E. This minimum 
window time-width of 2.13 ns is 
based upon the worst case FDDI 
PMD Active Input Interface 
optical conditions for peak-to-peak 
DCD (1.0 ns), DDJ (1.2 ns) and RJ 
(0.76 ns) presented to the 
receiver.
To test a receiver with the worst 
case FDDI PMD Active Input jitter 
condition requires exacting control 
over DCD, DDJ and RJ jitter components that is difficult to implement 
with production test equipment. The 
receiver can be equivalently tested 
to the worst case FDDI PMD input 
jitter conditions and meet the 
minimum output data window timewidth of 2.13 ns. This is accomplished by using a nearly ideal input 
optical signal (no DCD, insignificant 
DDJ and RJ) and measuring for a 
wider window time-width of 4.6 ns. 
This is possible due to the cumulative effect of jitter components 
through their superposition (DCD 
and DDJ are directly additive and 
RJ components are rms additive). 
Specifically, when a nearly ideal 
input optical test signal is used and 
the maximum receiver peak-to-peak 
jitter contributions of DCD (0.4 ns), 
DDJ (1.0 ns), and RJ (2.14 ns) exist, 
the minimum window time-width 
becomes 8.0 ns -0.4 ns - 1.0 ns - 2.14 
ns = 4.46 ns, or conservatively
4.6 ns. This wider window time-
width of 4.6 ns guarantees the FDDI 
PMD Annex E minimum window 
time-width of 2.13 ns under worst 
case input jitter conditions to the 
Hewlett-Packard receiver.
• Transmitter operating with an