General Description QSFP28 Direct Attach Cables are compliant with the SFF-8665 specifications. Various choices of wire gauge are available from 30 to 26 AWG with various choices of cable length (up to 5m). Features ◊ Compliant with SFF- 8665 ◊ Up to 28.3125Gbps data rate per channel ◊ Up to 5m transmission ◊ Operating temperature: 0~70℃ ◊ Single 3.3V power supply ◊ RoHS compliant Benefits ◊ Cost-effective copper solution ◊ Lowest total system power solution ◊ Lowest total system EMI solution ◊ Optimized design for Signal Integrity Applications ◊ 100G Ethernet Specification: Pin Function Definition Pin Logic Symbol Description 1   GND Ground 2 CML-I Tx2n Transmitter Inverted Data Input 3 CML-I Tx2p Transmitter Non-Inverted Data Input 4   GND Ground 5 CML-I Tx4n Transmitter Inverted Data Input 6 CML-I Tx4p Transmitter Non-Inverted Data Input 7   GND Ground 8 LVTTL-I ModSelL Module Select 9 LVTTL-I ResetL Module Reset 10   Vcc Rx +3.3V Power Supply Receiver 11 LVCMOS- I/O SCL 2-wire serial interface clock 12 LVCMOS- I/O SDA 2-wire serial interface data 13   GND Ground 14 CML-O Rx3p Receiver Non-Inverted Data Output 15 CML-O Rx3n Receiver Inverted Data Output 16   GND Ground 17 CML-O Rx1p Receiver Non-Inverted Data Output 18 CML-O Rx1n Receiver Inverted Data Output 19   GND Ground 20   GND Ground 21 CML-O Rx2n Receiver Inverted Data Output 22 CML-O Rx2p Receiver Non-Inverted Data Output 23   GND Ground 24 CML-O Rx4n Receiver Inverted Data Output 25 CML-O Rx4p Receiver Non-Inverted Data Output 26   GND Ground 27 LVTTL-O ModPrsL Module Present 28 LVTTL-O IntL Interrupt 29   Vcc Tx +3.3V Power supply transmitter 30   Vcc1 +3.3V Power supply 31 LVTTL-I LPMode Low Power Mode 32   GND Ground 33 CML-I Tx3p Transmitter Non-Inverted Data Input 34 CML-I Tx3n Transmitter Inverted Data Input 35   GND Ground 36 CML-I Tx1p Transmitter Non-Inverted Data Input 37 CML-I Tx1n Transmitter Inverted Data Input 38   GND Ground  General Product Characteristics QSFP+ DAC Specifications   Number of Lanes Tx & Rx Channel Data Rate 28.3125 Gbps Operating Temperature 0 to + 70°C Storage Temperature -40 to + 85°C Supply Voltage 3.3 V nominal Electrical Interface 38 pins edge connector Management Interface Serial, I2C High Speed Characteristics Parameter Symbol Min Typ Max Units Notes Differential Impedance Zd 90 100 110 Ω    Differential Input Return Loss    SDDXX <-12+2* SQRT (f) with f in GHz dB 0.01~4.1GHz <-6.3+13* Log10/(f/5.5) with f in GHz   dB  4.1~19GHz Common Mode Output Return Loss  SCCXX < -7+1.6*f with f in GHz dB 0.01~12.89GHz     -3 dB 12.89~19GHz Difference Waveform Distortion Penalty dWDPc     6.75 dB   VMA Loss L     4.4 dB    VMA Loss to Crosstalk Ratio VCR 32.5     dB   Mechanical Specifications The connector is compatible with the SFF-8665 specificatio Length (m) Cable AWG 1      30 2     30 3     30 5 26 Regulatory Compliance Feature Test Method Performance Electrostatic Discharge (ESD) to the Electrical Pins  MIL-STD-883C Method 3015.7  Class 1(>2000 Volts) Electromagnetic Interference(EMI) FCC Class B Compliant with Standards CENELEC EN55022 Class B CISPR22 ITE Class B  RF Immunity(RFI)  IEC61000-4-3 Typically Show no Measurable Effect from a 10V/m Field Swept from 80 to 1000MHz RoHS Compliance RoHS Directive 2011/65/EU and it's Amendment Directives 6/6 RoHS 6/6 compliant