14
13b. This specication is intended to indicate the performance of the receiver section of the transceiver when Input Optical Power signal characteristics 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 compo nents that
is dicult to implement with production test equipment. The receiver can be equivalently tested to the worst case FDDI PMD input jitter condi-
tions and meet the minimum output data window time-width of 2.13 ns. This is accom plished 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 cumula tive 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 trans mit ter and receiver sections of the transceiver.
14a. All conditions of Note 13a apply except that the measurement is made at the center of the symbol with no window time- width.
14b. All conditions of Note 13b apply except that the measurement is made at the center of the symbol with no window time-width.
15a. Systematic Jitter contributed by the receiver is dened as the combination of Duty Cycle Distortion and Data Dependent Jitter. Systematic Jitter is
measured at 50% threshold using a 155.52 MBd (77.5 MHz square- wave), 2
23
-1 psuedorandom data pattern input signal.
15b 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.
15c. 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.
16a. Random Jitter contributed by the receiver is specied with a 155.52 MBd (77.5 MHz square- wave) input signal.
16b. 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.
17. This value is measured during the transition from low to high levels of input optical power.
18. This value is measured during the transition from high to low levels of input optical power. At Loss of Signal assert, the receiver outputs Data
Out and Data Out Bar go to steady PECL levels High and Low respectively.
19. The Loss of Signal output shall be de-asserted within 100 μs after a step increase of the Input Optical Power.
20. Loss of Signal output shall be asserted within 350 μs after a step decrease in the Input Optical Power. At Loss of Signal Assert, the receiver
outputs Data Out and Data Out Bar go to steady PECL levels High and Low respectively.
21. The HFBR-57E0 transceiver complies with the requirements for the trade-os between center wavelength, spectral width, and rise/fall times
shown in Figure 3. This gure is derived from the FDDI PMD standard (ISO/IEC 9314-3 : 1990 and ANSI X3.166 - 1990) per the description in
ANSI T1E1.2 Revision 3. The interpretation of this gure is that values of Center Wavelength and Spectral Width must lie along the appropriate
Optical Rise/Fall Time curve.
