Recommended Circuit Schematic
Host Board Recommended Circuit Schematic
Next figure shows an example of a complete SFP host board schematic with connections to
SerDes/ASIC and protocol ICs.
Figure 7: Host Circuit
Host Board Recommended Power Supply
Figure 8 shows the recommended power supply filtering network.
Figure 8: Host Power Supply
PCB Layout Recommendation
Standard board layout practices such as connections to Vcc and GND planes with vias, use of short and equal‐
length differential signal traces are recommended.
RD± shall be routed as 100Ω differential controlled impedance traces.
TD± shall be routed as 100Ω differential controlled impedance traces.
For cage & host connector layout, please refer to manufacturer documentation.
Cable Driver
EQ
uC / EEPROM
HD-BNC
HD-BNC
TX SDI
RX SDI
SFP MODULE
LOS
RD-
RD+
SCL
SDA
TD-
TD+
TX_DIS
4.7k
4.7k
100
100
4.7k
+3.3V
+3.3V
+3.3V
4.7k
+3.3V
ASIC
ASIC
PROTOCOL
IC
MOD_DEF(2)
MOD_DEF(1)
PRESENCE
MOD_DEF(0)
4.7k
+3.3V
HOST
SFP Module
Host Board
VCC
1 uH
1 uH
0.1uF
0.1uF
0.1uF
10uF
10uF
10uF
VCC
3.3V
