General Description SFP28 Direct Attach Cables are compliant with SFF-8432 and SFF-8402 specifications. Various choices of wire gauge are available from 30 to 26 AWG with various choices of cable length (up to 5m). The SFP28 passive cable assemblies are high performance, cost effective I/O solutions for 25G Ethernet. SFP28 copper cables allow hardware manufactures to achieve high port density, configurability and utilization at a very low cost and reduced power budget. Features ◊ Up to 25.78125 Gbps data rate ◊ Up to 5 meter transmission ◊ Hot-pluggable SFP 20PIN footprint ◊ Improved Pluggable Form Factor(IPF) compliant for enhanced EMI/EMC performance ◊ Compatible to SFP28 MSA ◊ Compatible to SFF-8402 and SFF-8432 ◊ Temperature Range: 0~ 70 °C ◊ RoHS Compatible Benefits ◊ Cost-effective copper solution ◊ Lowest total system power solution ◊ Lowest total system EMI solution ◊ Optimized design for Signal Integrity Applications ◊ 25G Ethernet High Speed Characteristics Parameter Symbol Min Typical Max Unit Note Differential Impedance RIN,P-P 90 100 110 Ώ   Insertion loss SDD21 8   22.48 dB At 12.8906 GHz Differential Return Loss SDD11   12.45   See 1 dB At 0.05 to 4.1 GHz SDD22 3.12   See 2 dB At 4.1 to 19 GHz     Common-mode to SCC11       dB   common-mode 2     At 0.2 to 19 GHz SCC22     output return loss                             Differential to common-mode SCD11   12   See 3 dB   At 0.01 to 12.89 GHz           return loss SCD22 10.58   See 4   At 12.89 to 19 GHz                               10         At 0.01 to 12.89 GHz Differential to common Mode SCD21-IL       See 5 dB   At 12.89 to 15.7 GHz Conversion Loss           6.3         At 15.7 to 19 GHz Channel Operating Margin COM 3     dB   Pin Descriptions SFP28 Pin Function Definition Pin Logic Symbol Name/Description Notes 1   VeeT Transmitter Ground   2 LV-TTL-O TX_Fault N/A 1 3 LV-TTL-I TX_DIS Transmitter Disable 2 4 LV-TTL-I/O SDA Tow Wire Serial Data   5 LV-TTL-I SCL Tow Wire Serial Clock   6   MOD_DEF0 Module present, connect to VeeT   7 LV-TTL-I RS0 N/A 1 8 LV-TTL-O LOS LOS of Signal 2 9 LV-TTL-I RS1 N/A 1 10   VeeR Reciever Ground   11   VeeR Reciever Ground   12 CML-O RD- Reciever Data Inverted   13 CML-O RD+ Reciever Data Non-Inverted   14   VeeR Reciever Ground   15   VccR Reciever Supply 3.3V   16   VccT Transmitter Supply 3.3V   17   VeeT Transmitter Ground     18 CML-I TD+   Transmitter Data Non-Inverted     19 CML_I TD-   Transmitter Data Inverted     20   VeeT   Transmitter Ground   1. Signals not supported in SFP+ Copper pulled-downto VeeT with 30K ohms resistor   2. Passive cable assemblies do not support LOS and TX_DIS   Mechanical Specifications The connector is compatible with the SFF-8432 specification.   Length (m) Cable AWG 1 30 2 30 3 30/26 4 26 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