QSFP28 Pin Description
QSFP Pin Description
| Connector Pin Number | Symbol | Signal Description |
|---|---|---|
| 1 | GND | Ground |
| 2 | Tx2n | Connected to Port 2 lane Rx Inverted Data |
| 3 | Tx2p | Connected to Port 2 lane Rx Non-Inverted Data |
| 4 | GND | Ground |
| 5 | Tx4n | Connected to Port 4 lane Rx Inverted Data |
| 6 | Tx4p | Connected to Port 4 lane Rx Non-Inverted Data |
| 7 | GND | Ground |
| 8 | Mod-SelL | Cable/Module Select |
| 9 | ResetL | Cable/Module Reset |
| 10 | Vcc Rx | +3.3 V Power supply receiver |
| 11 | SCL | 2-wire serial interface clock |
| 12 | SDA | 2-wire serial interface data |
| 13 | GND | Ground |
| 14 | Rx3p | Connected to Port 3 lane Tx Non-Inverted Data |
| 15 | Rx3n | Connected to Port 3 lane Tx Inverted Data |
| 16 | GND | Ground |
| 17 | Rx1p | Connected to Port 1 lane Tx Non-Inverted Data |
| 18 | Rx1n | Connected to Port 1 lane Tx Inverted Data |
| 19 | GND | Ground |
| 20 | GND | Ground |
| 21 | Rx2n | Connected to Port 2 lane Tx Inverted Data |
| 22 | Rx2p | Connected to Port 2 lane Tx Non-Inverted Data |
| 23 | GND | Ground |
| 24 | Rx4n | Connected to Port 4 lane Tx Inverted Data |
| 25 | Rx4p | Connected to Port 4 lane Tx Non-Inverted Data |
| 26 | GND | Ground |
| 27 | ModPrsL | Module/cable Present |
| 28 | IntL | Interrupt |
| 29 | Vcc Tx | +3.3 V Power supply transmitter |
| 30 | Vcc 1 | +3.3 V Power Supply |
| 31 | LPMode | Low Power Mode |
| 32 | GND | Ground |
| 33 | Tx3p | Connected to Port 3 lane Rx Non-Inverted Data |
| 34 | Tx3n | Connected to Port 3 lane Rx Inverted Data |
| 35 | GND | Ground |
| 36 | Tx1p | Connected to Port 1 lane Rx Non-Inverted Data |
| 37 | Tx1n | Connected to Port 1 lane Rx Inverted Data |
| 38 | GND | Ground |
SFP28 Pin Description
Rear View of Module with Pin Placement
SFP Pin Description
| Pin | Symbol Name | Description | Note |
|---|---|---|---|
| 1 | VeeT | Module Transmitter Ground | -- |
| 2 | TX_Fault | Module Transmitter Fault | a |
| 3 | TX_Disable | Transmitter Disable. Turns off transmitter laser output | b |
| 4 | SDA | 2-wire Serial Interface Data Line | c |
| 5 | SCL | 2-wire Serial Interface Clock Line | d |
| 6 | MOD_ABS | Module Absent. Grounded within the module | d |
| 7 | RS0 | No connection required | -- |
| 8 | Rx_LOS | Loss of Signal indication. Logic 0 indicates normal operation. | d |
| 9 | RS1 | No connection required | -- |
| 10 | VeeR | Receiver Ground (Common with Transmitter Ground) | a |
| 11 | VeeR | Receiver Ground (Common with Transmitter Ground) | a |
| 12 | RD- | Receiver Inverted DATA out. AC Coupled | -- |
| 13 | RD+ | Receiver Non-inverted DATA out. AC Coupled | -- |
| 14 | VeeR | Receiver Ground (Common with Transmitter Ground) | a |
| 15 | VccR | Receiver Power Supply | -- |
| 16 | VccT | Transmitter Power Supply | -- |
| 17 | VeeT | Transmitter Ground (Common with Receiver Ground) | a |
| 18 | TD+ | Transmitter Non-Inverted DATA in. AC Coupled | -- |
| 19 | TD- | Transmitter Inverted DATA in. AC Coupled | -- |
| 20 | VeeT | Transmitter Ground (Common with Receiver Ground) | a |
Notes:
- TFAULT is an open collector/drain output, which should be pulled up with a 4.7k-10k Ohms resistor on the host board if intended for use. Pull up voltage should be between 2.0V to Vcc + 0.3V. A high output indicates a transmitter fault caused by either the TX bias current or the TX output power exceeding the preset alarm thresholds. A low output indicates normal operation. In the low state, the output is pulled to <0.8V.
- Laser output disabled on TDIS >2.0V or open, enabled on TDIS <0.8V
- Should be pulled up with 4.7kΩ-10kΩ on host board to a voltage between 2.0V and 3.6V. MOD_ABS pulls line low to indicate module is plugged in.
- LOS is open collector output. Should be pulled up with 4.7kΩ-10kΩ on host board to a voltage between 2.0V and 3.6V. Logic 0 indicates normal operation; logic 1 indicates loss of signal.
RJ-45 CONSOLE and I²C Interface
RJ-45 Console and I²C interfaces are integrated in the same connector. Due to that, connecting any cable other than the Mellanox supplied console cable may cause an I²C hang.
Using uncertified cables may damage the I²C interface. Refer to the Replacement Parts Ordering Numbers appendix for harness details.
| Signal | Pin# | Color |
|---|---|---|
| Not connected | 1 | G/W |
| I²C_SCL | 2 | G |
| TXD | 3 | O/W |
| Not connected | 4 | Bl |
| GND | 5 | Bl/W |
| RXD | 6 | O |
| I²C_SDA | 7 | Br/W |
| Not connected | 8 | Br |
RJ45 to DB9 Harness Pinout
The RS232 harness cable (DB9 to RJ45) is provided within the package to connect a host PC to the system's Console RJ45 port.
RJ45 to DB9 Harness Pinout
RJ45 to RJ45 Harness
2m RJ45-to-RJ45 serial port cable is provided in the SN2410 and SN2700 packages.
The harness must be used when connecting the switch serial port with the terminal server/console server.
The new harness can be extended by an ordinary flat 1-to-1 RJ45 cable.
