afct-5942tltgz Avago Technologies, afct-5942tltgz Datasheet - Page 7

• Manufacturer Part Number: afct-5942tltgz
• Description: Single Mode Sff Transceivers For Sonet Oc-48/sdh Stm-16 Singlerate Operation Part Of The Avago Technologies? Metrak Family
• Manufacturer: Avago Technologies

Application Information
The Applications Engineering Group at Avago Tech-
nologies is available to assist you with technical under-
standing and design trade-offs associated with these
transceivers. You can contact them through your Avago
Technologies sales representative.
The following information is provided to answer some of
the most common questions about the use of the parts.
Figure 6. Recommended Interface Circuit
7
B
T
B
P
P
V
Note:
Note A: CIRCUIT ASSUMES OPEN EMITTER OUTPUT.
Note B: CIRCUIT ASSUMES HIGH IMPENDANCE INTERNAL BIAS @ V
Note C: THE BIAS RESISTOR FOR VpdR SHOULD NOT EXCEED 2 kΩ
DIS
MON
MON
MON
CC
MON
T
R
X
X
RX (+3.3 V)
(LVTTL)
+
-
+
-
NOTE C
C1 = C2 = C3 = 10 nF or 100 nF
TD+, TD- INPUTS ARE INTERNALLY TERMINATED AND AC COUPLED.
RD+, RD- OUTPUTS ARE INTERNALLY BIASED AND AC COUPLED.
2 kΩ
20 19 18 17 16 15 14 13 12 11
1
3 kΩ
2
3
10 nF
4
5
6
7
8
9 10
CC
- 1.3 V.
C2
C1
10 µF
10 µF
1 µH
1 µH
Optical Power Budget and Link Penalties
The worst-case Optical Power Budget (OPB) in dB for a
fiber-optic link is determined by the difference between
the minimum transmitter output optical power (dBm avg)
and the lowest receiver sensitivity (dBm avg). This OPB
provides the necessary optical signal range to establish a
working fiber-optic link. The OPB is allocated for the fiber-
optic cable length and the corresponding link penalties.
For proper link performance, all penalties that affect the
link performance must be accounted for within the link
optical power budget.
Electrical and Mechanical Interface
Recommended Circuit
Figure 6 shows the recommended interface for deploying
the Avago Technologies transceivers in a +3.3 V system.
Z= 50Ω
Z= 50Ω
Z= 50Ω
Z= 50Ω
V
CC
(+3.3 V)
C3
130Ω
100Ω
130Ω
TD-
TD+
RD+
RD-
SD
LVTTL
V
CC
V
(+3.3 V)
CC
(+3.3 V)
NOTE A
NOTE B