The battle for next-generation optical transceivers remains active. The three leading specifications duking it out include COBO, OSFP and QSFP-DD. While all have their pros and cons, the industry continues to sort out the best solutions for the front panel and mid-board optical engines.
What is QSFP-DD?
Current QSFP solutions meet the existing demands of the telecom/datacom industries. The QSFP-DD MSA focuses on a next generation high-density, high-speed pluggable backwards compatible module form factor. As advanced ASIC and FPGA solutions hit the market, a next-generation module that overcomes the limitations of QSFP needs to perform at 50 Gbps+ per channel.
QSFP-DD pluggable modules can support quadruple the bandwidth of conventional QSFP modules by adding a second row of contacts enabling support for an eight-lane electrical interface. Systems designed for QSFP-DD modules will be backwards compatible with existing QSFP form factors and provide increased flexibility for end users, network platform designers and integrators.
QSFP-DD solutions will also support 25 Gbps NRZ/50 Gbps PAM4 speeds to provide a path to 400 Gbps modules. Additional details on the QSFP-DD form factor specification are available via free download at the QSFP-DD MSA website, www.qsfp-dd.com.
New QSFP-DD Hardware Specification
Samtec and 61 other industry leaders today announced the Version 3.0 of the QSFP-DD Hardware Specification. The QSFP-DD specification defines mechanical, electrical, and thermal management requirements to enable multi-vendor interoperability.
The new specification defines a module and both single height and stacked height integrated cage/connector systems. The new multi-lane pluggable form factor will support Ethernet, Fibre Channel and InfiniBand protocols at data rates up to 400 Gbps in aggregate.
Samtec Flyover QSFP Systems
The new QSFP-DD standard focuses on addressing data rate bottlenecks on the front panel and between systems. But what about from the FPGA or ASIC on the line card to the front panel? That is where Samtec’s Flyover solutions provide support.
Samtec’s Flyover QSFP Systems provide improved signal integrity and architectural flexibility by flying critical high-speed signals over lossy PCB materials and directly to the panel via ultra-low skew twinax cable.
The ultra-high-density design includes sideband signaling via press-fit contacts to help increase airflow, and a multitude of “End 2” options allow for maximum design flexibility.
Samtec recently released its new Flyover QSFP Application Design Guide. This new resource outlines the resources and product solutions Samtec has developed for routing high-speed signals from QSFP and QSFP-DD cages over lossy PCBs via ultra-low skew twinax cable.
FQSFP Series (QSFP28) Features
Samtec FQSFP series features include:
- 4 Channels (x4 Bidirectional, 8 Differential Pairs)
- 25 Gbps NRZ per channel
- Aggregate: 100 Gbps NRZ (200 Gbps PAM4)
- Compatible with all QSFP cable assemblies
- Heat dissipation: ~3.5 W / cable
FQSFP-DD Series (QSFP28-DD) Features
Samtec FQSFP-DD series features include:
- 8 Channels (x8 Bidirectional, 16 Differential Pairs)
- 25 Gbps NRZ per channel
- Aggregate: 200 Gbps NRZ (400 Gbps PAM4)
- Belly-to-Belly mating for maximum density
- Heat dissipation: ~7 W / cable
For more information on FQSFP and FQSFP-DD solutions, please visit Samtec’s Flyover QSFP28 Cable System product page.