Description

Farsince 400G QSFP‑DD passive direct‑attach copper cable is a twinax assembly designed for high‑density 400GbE links over very short distances. Each end integrates a hot‑pluggable QSFP‑DD module that carries eight 50G PAM4 electrical lanes (8×50G) for an aggregate 400 Gbps without optical transceivers. Typical deployments include switch‑to‑switch or switch‑to‑router connections within the same rack or across adjacent racks in cloud, AI/ML and SDN environments where deterministic latency and straightforward patching are required.

With no active components, the DAC adds virtually no latency and draws only a small ID current from the host. Controlled‑impedance copper pairs and comprehensive shielding help maintain low insertion loss and crosstalk, while a 33 mm minimum bend radius supports compact routing in dense panels. The cable follows QSFP‑DD MSA mechanics and CMIS 4.0 and meets IEEE 802.3cd 400GBASE‑CR8 electrical specifications for broad interoperability. Farsince supports length and coding customization, project labeling, and batch test documentation to align with data‑center rollout and maintenance needs.

Specifications

• Product Type: 400G Passive Direct Attach Copper (DAC)
• Host Interface: QSFP‑DD to QSFP‑DD
• Data Rate: 400 Gbps aggregate (8×50G PAM4)
• Wire Gauge: 30 AWG
• Cable Structure: Shielded twinax pairs
• Minimum Bend Radius: 33 mm
• Power Design: Passive; ≤0.1 W per end for ID
• Application: In‑rack 400GbE switch/router interconnects
• Installation: Hot‑pluggable QSFP‑DD with pull‑tab
• Operating Temperature: 0 to +70°C
• Jacket Material: Abrasion‑resistant jacket with optional braided sleeve
• Compatibility: IEEE 802.3cd 400GBASE‑CR8; QSFP‑DD MSA; CMIS 4.0
• Compliance: RoHS, REACH
• Customization: Lengths, vendor coding and labeling available