Credo introduced the Blue Heron 224G AI scale-up retimer, positioning it as the industry’s first multiprotocol 224G retimer designed to support UALink, Ethernet for Scale-Up Networking (ESUN), and Ethernet. The device targets rack-scale AI systems where electrical reach and flexible hardware placement constrain scale-up architectures.
The Blue Heron retimer addresses the electrical limits of 224G scale-up cable and PCB backplanes, which typically restrict reach to half-rack spans and force GPUs and switch ASICs to sit at the rear of trays. Credo said the multiprotocol retimer enables full recovery of links exceeding 40 dB, allowing system designers to build rack-scale cable backplanes and place GPUs and switch ICs more flexibly across trays. The device supports UALink, ESUN, and Ethernet at Layer 1, aligning with IEEE 802.3 224G signaling.
Credo built Blue Heron on an advanced 3nm process using its 224G SerDes, incorporating a 30-tap feed-forward equalizer and an additional 16 taps for reflection cancellation. The company said the architecture supports extended-reach cable and backplane links while maintaining low latency for AI scale-up workloads. Blue Heron is sampling now, with production quantities planned for calendar Q3 2026.
- 224G long-reach retimer and gearbox supporting UALink, ESUN, and Ethernet
- Designed for extended cable and PCB backplane links beyond 40 dB
- Enables flexible rack-scale and tray-level placement of GPUs and switch ICs
- Built on a 3nm process with Credo’s 224G SerDes architecture
- Mission-mode FEC monitoring and advanced telemetry for link health
- Integrated with Credo’s PILOT debug and analytics GUI
“The fast-growing scale-up market consists of a diversity of scale-up protocols such as UALink, ESUN and Ethernet which converge at layer 1 on the 224G 802.3 standard,” said Sandeep Shah, AVP of Product for Credo’s Retimer Products. “Credo’s leading Blue Heron 224G retimer can support all of these standards enabling a simple, multi-protocol solution for customers.”
🌐 Analysis
Credo’s Blue Heron launch highlights how 224G electrical signaling has become a common physical-layer foundation for multiple AI scale-up fabrics, rather than a single dominant protocol. The announcement also underscores growing industry momentum behind multiprotocol silicon as hyperscalers and AI platform builders evaluate UALink, ESUN, and Ethernet in parallel for rack-scale architectures.
