NetLight
1417G5 and 1417H5-Type
ATM/SONET/SDH Transceivers with Clock Recovery
Data Sheet
January 2000
Application Information
(continued)
Noise that couples into the receiver through the power
supply pins can also degrade performance. It is recom-
mended that the pi filter, shown in Figure 2, be used for
both the transmitter and receiver power supplies.
decipher the proper logic levels and can cause transi-
tions to occur where none were intended. Also, by min-
imizing high-frequency ringing, possible EMI problems
can be avoided.
The signal-detect output is LVTTL logic. A logic low at
this output indicates that the optical signal into the
receiver has been interrupted or that the light level has
fallen below the minimum signal detect threshold. This
output should not be used as an error rate indicator,
since its switching threshold is determined only by the
magnitude of the incoming optical signal.
Data Clock and Signal Detect Outputs
The data clock and signal detect outputs of the 1417
transceiver are driven by open-emitter NPN transistors,
which have an output impedance of approximately 7
Ω.
Each output can provide approximately 50 mA maxi-
mum current to a 50
Ω
load terminated to V
CC
– 2.0 V.
Due to the high switching speeds of ECL outputs,
transmission line design must be used to interconnect
components. To ensure optimum signal fidelity, both
data outputs (RD+/RD–) and clock outputs (CLK+/
CLK–) should be terminated identically. The signal
lines connecting the data and clock outputs to the next
device should be equal in length and have matched
impedances. Controlled impedance stripline or micros-
trip construction must be used to preserve the quality
of the signal into the next component and to minimize
reflections back into the receiver, which could degrade
its performance. Excessive ringing due to reflections
caused by improperly terminated signal lines makes it
difficult for the component receiving these signals to
Transceiver Processing
When the process plug is placed in the transceiver's
optical port, the transceiver and plug can withstand
normal wave soldering and aqueous spray cleaning
processes. However, the transceiver is not hermetic,
and should not be subjected to immersion in cleaning
solvents. The transceiver case should not be exposed
to temperatures in excess of 125
°C.
The transceiver
pins can be wave soldered at 250
°C
for up to 10 sec-
onds. The process plug should only be used once.
After removing the process plug from the transceiver, it
must not be used again as a process plug; however, if it
has not been contaminated, it can be reused as a dust
cover.
Transceiver Optical and Electrical Characteristics
Table 2. Transmitter Optical and Electrical Characteristics
(T
C
= –40
°C
to +85
°C;
V
CC
= 3.135 V to 3.465 V)
Parameter
Average Optical Output Power (EOL)
Optical Wavelength:
STM-1 (4 nm spectral width, maximum)
STM-4 (2.5 nm spectral width, maximum)
Dynamic Extinction Ratio
Power Supply Current
Input Data Voltage:
Low
High
Transmit Disable Voltage
Transmit Enable Voltage
Laser Bias Voltage
Laser Back-facet Monitor Voltage
Symbol
P
O
λ
C
1261
1274
EXT
I
CCT
V
IL
V
IH
V
D
V
EN
V
BIAS
V
BF
8.2
—
V
CC
– 1.81
V
CC
– 1.025
V
CC
– 1.3
V
EE
0
0.01
1360
1356
—
150
V
CC
– 1.62
V
CC
– 0.88
V
CC
V
EE
+ 0.8
0.70
0.20
nm
nm
dB
mA
V
V
V
V
V
V
Min
–15.0
Max
–8.0
Unit
dBm
4
Agere Systems Inc.
AGERE [ AGERE SYSTEMS ]
