12
9. 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 25 MBd (12.5 MHz square-wave) input 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.
10. The transmitter will provide this low level of Output Optical Power when driven by a Logic “0” input. This can be useful in link troubleshoot-
ing.
11. The relationship between Full Width Half Maximum and RMS values for Spectral Width is derived from the assumption of a Gaussian shaped
spectrum which results in a 2.35 X RMS = FWHM relationship.
12. The optical rise and fall times are measured from 10% to 90% when the transmitter is driven by a 25 MBd (12.5 MHz square-wave) input signal.
The ANSI T1E1.2 committee has designated the possibility of dening an eye pattern mask for the transmitter optical output as an item for
further study. Avago will incorporate this requirement into the specications for these products if it is dened. The HFBR-59XXL products
typically comply with the template requirements of CCITT (now ITU-T) G.957 Section 3.2.5, Figure 5 for the STM- 1 rate, excluding the optical
receiver lter normally associated with single mode ber measurements which is the likely source for the ANSI T1E1.2 committee to follow in
this matter.
13a. Systematic Jitter contributed by the transmitter is dened as the combination of Duty Cycle Distortion and Data Dependent Jitter. System-
atic Jitter is measured at 50% threshold using a 155.52 MBd (77.5 MHz square-wave), 2
23
-1 pseudorandom data pattern input signal.
13b. Duty Cycle Distortion contributed by the transmitter is measured at the 50% threshold of the optical output signal using an IDLE Line State, 125
MBd (62.5 MHz square-wave), input signal.
13c. Data Dependent Jitter contributed by the transmitter is specied with the FDDI test pattern described in FDDI PMD Annex A.5.
14a. Random Jitter contributed by the transmitter is specied with a 155.52 MBd (77.5 MHz square-wave) input signal.
14b. Random Jitter contributed by the transmitter is specied with an IDLE Line State, 125 MBd (62.5 MHz square-wave), input signal. See Applica-
tion Information - Transceiver Jitter Performance Section of this data sheet for further details.
15a. This specication is intended to indicate the performance of the receiver section of the transceiver when Input Optical Power signal character-
istics are present per the following denitions. 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 Rate (BER) better than or equal to 1
x 10
-10
.
At the Beginning of Life (BOL) over the specied operating temperature and voltage ranges 23 input is a 155.52 MBd, 2 - 1 PRBS data pattern
with 72 “1” s and 72 “0”s inserted per the CCITT (now ITU-T) recommendation G.958 Appendix I.
Receiver data window time-width is 1.23 ns or greater for the clock recovery circuit to operate in. The actual test data window time-width is
set to simulate the eect of worst case optical input jitter based on the transmitter jitter values from the specication tables. The test window
time-width is HFBR-5961L 3.32 ns.
Transmitter operating with a 155.52 MBd, 77.5 MHz square-wave, input signal to simulate any cross-talk present between the transmitter and
receiver sections of the transceiver.
15b. This specication is intended to indicate the performance of the receiver section of the transceiver when Input Optical Power signal char-
acteristics are present per the following denitions. 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 Rate (BER) better than
or equal to 2.5 x 10
-10
.
• At the Beginning of Life (BOL)
• Over the specied operating temperature and voltage ranges
• Input symbol pattern is the FDDI test pattern dened in FDDI PMD Annex A.5 with 4B/5B NRZI encoded data that contains a duty cycle base-
line wander eect 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 dicult 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 time-width of 2.13 ns. This is accomplished by using a nearly ideal input optical signal
(no DCD, insignicant DDJ and RJ) and measuring for a wider window time-width of 4.6 ns. This is possible due to the cumulative eect of jitter
components through their superposition (DCD and DDJ are directly additive and RJ components are rms additive). Specically, 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 Avago
receiver.
• Transmitter operating with an IDLE Line State pattern, 125 MBd (62.5 MHz square-wave), input signal to simulate any cross-talk present
between the transmitter and receiver sections of the transceiver.
16a. All conditions of Note 15a apply except that the measurement is made at the center of the symbol with no window time- width.
16b. All conditions of Note 15b apply except that the measurement is made at the center of the symbol with no window time-width.
17a. Systematic Jitter contributed by the receiver is dened as the combination of Duty Cycle Distortion and Data Dependent Jitter. System-
atic Jitter is measured at 50% threshold using a 155.52 MBd (77.5 MHz square- wave), 2
23
- 1 psuedorandom data pattern input signal.
17b. Duty Cycle Distortion contributed by the receiver is measured at the 50% threshold of the electrical output signal using an IDLE Line State,
125 MBd (62.5 MHz square-wave), input signal. The input optical power level is -20 dBm average.
17c. Data Dependent Jitter contributed by the receiver is specied with the FDDI DDJ test pattern described in the FDDI PMD Annex A.5. The
input optical power level is -20 dBm average.
18a. Random Jitter contributed by the receiver is specied with a 155.52 MBd (77.5 MHz square- wave) input signal.
18b. Random Jitter contributed by the receiver is specied with an IDLE Line State, 125 MBd (62.5 MHz square-wave), input signal. The input
optical power level is at maximum “P
IN Min.
(W)”. See Application Information - Transceiver Jitter Section for further information.
