Features ◊ Support 4x25GBASE-SR application ◊ Compliant to QSFP28 MSA SFF-8636 and SFP28 MSA SFF-8431 and SFF- 8472 ◊ Multi rate of up to 25.78125Gbps per lane ◊ Transmission distance up to 50m ◊ +3.3V single power supply ◊ Low power consumption ◊ UL certification cables (optional) ◊ Operating temp Commercial: 0°C to +70 °C ◊ RoHS compliant Applications ◊ 4x25Gbe-SR ◊ Other optical links Specification: Absolute Maximum Ratings Table1- Absolute Maximum Ratings Parameter Symbol Min. Typical Max. Unit Notes Supply Voltage Vcc3 -0.5 - +3.6 V Storage Temperature Ts -10 - +70 °C Operating Humidity RH +5 - +85 % 1 Note: 1 No condensation Recommended Operating Conditions Table 2- Recommended operating Conditions Parameter Symbol Min. Typical Max. Unit Notes Operating Temperature TC 0 - +70 °C Power Supply Voltage Vcc 3.14 3.3 3.47 V Power Dissipation per QSFP28 Pd - - 2.5 W Power Dissipation per SFP28 Pd - - 1.0 W 1 Bit Rate per Lane BR 10.3125 25.78125 - Gbps Note: 1 Per terminal Electrical Characteristics Table 3- Electrical Characteristics for QSFP28 Parameter Symbol Min. Typ. Max. Units Notes ModSelL Module Select VOL 0 - 0.8 V Module Unselect VOH 2.5 - VCC V LPMode Low Power Mode VIL 0 - 0.8 V Normal Operation VIH 2.5 - VCC+0.3 V ResetL Reset VIL 0 - 0.8 V Normal Operation VIH 2.5 - VCC+0.3 V ModPrsL Normal Operation VOL 0 - 0.4 V IntL Interrupt VOL 0 - 0.4 V Normal Operation VoH 2.4 - VCC V Electrical Transmitter Characteristics Differential Date Input Swing Vin,P-P 200 - 1600 mV Output Differential Impedance ZIN 90 100 110 Ω Electrical Receiver Characteristics Differential Data Output Swing Vout 200 - 800 mVPP Bit Error Rate BER E-12 1 Input Differential Impedance ZD 90 100 110 Ω Note: 1 PRBS2^31-1@25.78125Gbps Table 4- Electrical Characteristics for SFP28 Parameter Symbol Min. Typ. Max. Units Notes Electrical Transmitter Characteristics Differential Data Input Swing Vin,P-P 200 - 1600 mVPP Input Differential Impedance ZIN 90 100 110 Ω Tx_Fault Normal Operation VOL 0 - 0.8 V Transmitter Fault VOH 2.0 - VCC V Tx_Disable Normal Operation VIL 0 - 0.8 V Laser Disable VIH 2.0 - VCC+0.3 V Electrical Receiver Characteristics Differential Date Output Vout 400 - 800 mV Bit Error Rate BER - - E-12 - Output Differential Impedance ZD 90 100 110 Ω Rx_LOS Normal Operation VOL 0 - 0.8 V Lose Signal VoH 2.0 - VCC V Pin arrangement Figure 1, Pin View for QSFP28 Table 5- Pin Function Definitions for QSFP28 Pin Symbol Name/Description Notes 1 GND Ground 1 2 Tx2n Transmitter Inverted Data Input 3 Tx2p Transmitter Non-Inverted Data Input 4 GND Ground 1 5 Tx4n Transmitter Inverted Data Input 6 Tx4p Transmitter Non-Inverted Data Input 7 GND Ground 1 8 ModSelL Module Select 9 ResetL Module Reset 10 Vcc Rx +3.3V Power Supply Receiver 11 SCL 2-wire serial interface clock 12 SDA 2-wire serial interface data 13 GND Ground 1 14 Rx3p Receiver Non-Inverted Data Output 15 Rx3n Receiver Inverted Data Output 16 GND Ground 1 17 Rx1p Receiver Non-Inverted Data Output 18 Rx1n Receiver Inverted Data Output 19 GND Ground 1 20 GND Ground 1 21 Rx2n Receiver Inverted Data Output 22 Rx2p Receiver Non-Inverted Data Output 23 GND Ground 1 24 Rx4n Receiver Inverted Data Output Pin Symbol Name/Description Notes 25 Rx4p Receiver Non-Inverted Data Output 26 GND Ground 1 27 ModPrsL Module Present 28 IntL Interrupt 29 Vcc Tx +3.3V Power supply transmitter 30 Vcc1 +3.3V Power supply 31 LPMode Low Power Mode 32 GND Ground 1 33 Tx3p Transmitter Non-Inverted Data Input 34 Tx3n Transmitter Inverted Data Input 35 GND Ground 1 36 Tx1p Transmitter Non-Inverted Data Input 37 Tx1n Transmitter Inverted Data Input 38 GND Ground 1 Note: 1. Circuit ground is internally isolated from chassis ground. Figure 2, Pin View for SFP28 Table 6-Pin Function Definitions Pin Symbol Name/Description Notes 1 VEET Module Transmitter Ground 1 2 TX_FAULT Module Transmitter Fault 2 3 TX_DISABLE Transmitter Disable; Turns off transmitter laser output 3 4 SDA 2-Wire Serial Interface Data Line (MOD-DEF2) 5 SCL 2-Wire Serial Interface Clock (MOD-DEF1) 6 MOD_ABS Module Absent, connected to VEET or VEER in the module 2 7 RS0 Rate Select 0, optionally controls SFP+ module receiver 4 8 RX_LOS Receiver Loss of Signal Indication (In FC designated as Rx_LOS and in Ethernet designated as NOT Signal Detect) 2 9 RS1 Rate Select 1, optionally controls SFP+ module transmitter 4 Pin Symbol Name/Description Notes 10 VEER Module Receiver Ground 1 11 VEER Module Receiver Ground 1 12 RD- Receiver Inverted Data Output 13 RD+ Receiver Non-Inverted Data Output 14 VEER Module Receiver Ground 1 15 VCCR Module Receiver 3.3 V Supply 16 VCCT Module Transmitter 3.3 V Supply 17 VEET Module Transmitter Ground 1 18 TD+ Transmitter Non-Inverted Data Input 19 TD- Transmitter Inverted Data Input 20 VEET Module Transmitter Ground 1 Note: The module ground pins are isolated from the module case. The pins shall be pulled up with 4.7K-10Kohms to a voltage between 3.14V and 3.46V on host board. The pin is pulled up to VCCT with a 4.7K-10KΩ resistor in the module. See SFF-8472 Rev12.2 Table 10-2. Recommended Circuit Figure 3, Recommended Interface Circuit for QSFP28 Figure 4, Recommended Host Board Power Supply Circuit for SFP28 Figure 5, Recommended Interface Circuit for SFP28 Monitoring Specification Figure 6, Memory Map for QSFP28 Figure 7, Memory Map for SFP28 Mechanical Unit mm Figure 8, Mechanical Diagram Table 7- Cable Length Cable Length L1(Unit: m) Tolerant(Unit: cm) ≤1.0 +5/-0 1.0<L≤4.5 +15/-0 4.5<L≤14.5 +30/-0 >14.5 +2%/-0 Table 8- Breakout Cable Nominal Length Total Length L1 (Unit: m) Breakout Point Measured from SFPL2(Unit: m) 1 0.7 2 1.4 3 2 ≥5 3 Warnings Handling Precautions: This device is susceptible to damage as a result of electrostatic discharge (ESD). A static free environment is highly recommended. Follow guidelines according to proper ESD procedures. Laser Safety: Radiation emitted by laser devices can be dangerous to human eyes. Avoid eye exposure to direct or indirect radiation.