3
Notes:
1)
TX Fault
is an open collector/drain output, which should be pulled up with a 4.7k – 10k
resistor on the host board. When high, output indicates a laser fault of some kind. Low
indicates normal operation. In the low state, the output will be pulled to < 0.8V.
2)
TX disable
is an input that is used to shut down the transmitter optical output. It is pulled
up within the module with a 4.7k – 10k
resistor. Its states are:
Low (0 – 0.8V): Transmitter on
(>0.8, < 2.0V): Undefined
High (2.0 – 3.465V): Transmitter Disabled
Open: Transmitter Disabled
3)
Mod-Def 0,1,2.
These are the module definition pins. They should be pulled up with a 4.7k
– 10k
resistor on the host board. The pull-up voltage shall be VccT or VccR.
Mod-Def 0 is grounded by the module to indicate that the module is present Mod-Def 1 is the
clock line of two wire serial interface for serial ID Mod-Def 2 is the data line of two wire serial
interface for serial ID.
4)
LOS
(
Loss of Signal)
is an open collector/drain output, which should be pulled up with a
4.7k – 10k
resistor. When high, this output indicates the received optical power is below the
worst-case receiver sensitivity. Low indicates normal operation. In the low state, the output
will be pulled to < 0.8V.
5)
VeeR
and
VeeT
may be internally connected within the SFP module.
6)
Rx_Data-/+:
These are the differential receiver outputs. They are AC coupled
100
differential lines should be terminated with 100
(differential) at the user SERDES. The
AC coupling is done inside the module and is thus not required on the host board. The
voltage swing on these lines will be between 600 and 900 mV differential when properly
terminated.
7)
VccR
and
VccT
are the receiver and transmitter power supplies. They are defined as
3.3V±5% at the SFP connector pin. Maximum supply current is 200 mA. Recommended host
board power supply filtering is shown below. Inductors with DC resistance of less than 1
should be used in order to maintain the required voltage at the SFP input pin with 3.3V. When
the recommended supply filtering network is used, hot plugging of the SFP transceiver
module will result in an inrush current of no more than 30 mA greater than the steady state
value. VccR and VccT may be internally connected within the SFP transceiver module.
8)
Tx_Data-/+:
These are the differential transmitter inputs. They are AC-coupled, differential
lines with 100
termination inside the module. The AC coupling is done inside the module
and is thus not required on the host board. The inputs will accept differential swings of 200 –