22
10. Random Jitter contributed by the
receiver is specified with an IDLE
Line State, 125 MBd (62.5 MHz
square-wave), input signal. The
input optical power level is at maxi-
mum “PIN Min. (W)”. See Application
Information - Transceiver Jitter
Section for further information.
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
Agilent’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 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.
13. 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.
14. This parameter complies with the
FDDI PMD requirements for the
tradeoffs between center wave-
length, spectral width, and rise/fall
times shown in Figure 9.
15. 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.
16. Duty Cycle Distortion contributed
by the transmitter is measured at a
50% threshold using 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.
17. 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.
18. 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.
Notes:
1. This is the maximum voltage that
can be applied across the Differen-
tial Transmitter Data Inputs to
prevent damage to the input ESD
protection circuit.
2. The outputs are terminated with
50 Ω connected to V
CC -2 V.
3. The power supply current needed to
operate the transmitter is provided
to differential ECL circuitry. This
circuitry maintains a nearly con-
stant current flow from the power
supply. Constant current operation
helps to prevent unwanted electrical
noise from being generated and
conducted or emitted to neighboring
circuitry.
4. This value is measured with the out-
puts terminated into 50 Ω connected
to V
CC - 2 V and an Input Optical
Power level of -14 dBm average.
5. The power dissipation value is the
power dissipated in the receiver
itself. Power dissipation is calcu-
lated as the sum of the products of
supply voltage and currents, minus
the sum of the products of the
output voltages and currents.
6. These values are measured with
respect to VCC with the output
terminated into 50 Ω connected to
VCC - 2 V.
7. The output rise and fall times are
measured between 20% and 80%
levels with the output connected to
VCC -2 V through 50 Ω.
8. Duty Cycle Distortion contributed
by the receiver is measured at the
50% threshold using an IDLE Line
State, 125 MBd (62.5 MHz square-
wave), input signal. The input
optical power level is -20 dBm
average. See Application
Information - Transceiver Jitter
Section for further information.
9. Data Dependent Jitter contributed
by the receiver is specified with the
FDDI DDJ test pattern described in
the FDDI PMD Annex A.5. The
input optical power level is -20 dBm
average. See Application Informa-
tion - Transceiver Jitter Section for
further information.