7
Notes:
1. TX_FAULT is an open collector/drain output, which must be pulled up with a 4.7 k – 10 kΩ resistor on the host board. When high, this output
indicates a laser fault of some kind. Low indicates normal operation. In the low state, the output will be pulled to < 0.8 V.
2. TX_DISABLE is an input that is used to shut down the transmitter optical output. It is internally pulled up (within the transceiver) with a 6.8 kΩ
resistor.
Low (0 – 0.8 V): Transmitter on
Between (0.8 V and 2.0 V): Undened
High (2.0 – Vcc max) or OPEN: Transmitter Disabled
3. The signals Mod-Def 0, 1, 2 designate the two wire serial interface pins. They must be pulled up with a 4.7 k – 10 kΩ resistor on the host board.
Mod-Def 0 is grounded by the module to indicate the module is present
Mod-Def 1 is serial clock line (SCL) of two wire serial interface
Mod-Def 2 is serial data line (SDA) of two wire serial interface
4. RATE_SELECT is an input used to control transceiver compatiility for multiple rates. It is internally pulled down with a >30 kΩ resistor.
Low (0 - 0.8 V) or OPEN: Low Bit Rate Compatibility per SFF-8074i (1.0625 Gb/s and 2.125 Gb/s per SFF-8079)
Between (0.8 V and 2.0 V) Undened per SFF-8074i
High (2.0 – Vcc max): High Bit Rate Compatibility per SFF-8074i (2.125 Gb/s and 4.25 Gb/s per SFF-8079)
5. RX_LOS (Rx Loss of Signal) is an open collector/drain output that must be pulled up with a 4.7 k – 10 kΩ resistor on the host board. When high,
this output indicates the received optical power is below the worst case receiver sensitivity (as dened by the standard in use). Low indicates
normal operation. In the low state, the output will be pulled to < 0.8 V.
6. RD-/+ designate the dierential receiver outputs. They are AC coupled 100 Ω dierential lines which should be terminated with 100 Ω dierential
at the host SERDES input. AC coupling is done inside the transceiver and is not required on the host board. The voltage swing on these lines will
be between 600 and 1600 mV dierential (300 – 800 mV single ended) when properly terminated.
7. VccR and VccT are the receiver and transmitter power supplies. They are dened at the SFP connector pin. The maximum supply current is 300
mA and the associated in-rush current will typically be no more than 30 mA above steady state after 2 microseconds.
8. TD-/+ designate the dierential transmitter inputs. They are AC coupled dierential lines with 100 Ω dierential termination inside the module.
The AC coupling is done inside the module and is not required on the host board. The inputs will accept dierential swings of 400 – 2400 mV
(200 – 1200 mV single ended), though it is recommended that values between 500 and 1200 mV dierential (250 – 600 mV single ended) be
used for best EMI performance.
Table 2. Pin Description
Pin Name Function/Description Notes
1 VeeT Transmitter Ground
2 TX_FAULT Transmitter Fault Indication – High indicates a fault condition Note 1
3 TX_DISABLE Transmitter Disable – Module electrical input disables on high or open Note 2
4 MOD-DEF2 Module Denition 2 – Two wire serial ID interface data line (SDA) Note 3
5 MOD-DEF1 Module Denition 1 – Two wire serial ID interface clock line (SCL) Note 3
6 MOD-DEF0 Module Denition 0 – Grounded in module (module present indicator) Note 3
7 Rate Select Bit Rate Parametric Optimization Note 4
8 RX_LOS Loss of Signal – High indicates loss of received optical signal Note 5
9 VeeR Receiver Ground
10 VeeR Receiver Ground
11 VeeR Receiver Ground
12 RD- Inverse Received Data Out Note 6
13 RD+ Received Data Out Note 6
14 VeeR Receiver Ground
15 VccR Receiver Power + 3.3 V Note 7
16 VccT Transmitter Power + 3.3 V Note 7
17 VeeT Transmitter Ground
18 TD+ Transmitter Data In Note 8
19 TD- Inverse Transmitter Data In Note 8
20 VeeT Transmitter Ground
