Broadcom Expands 200G/lane DSP PHY Portfolio for AI Infrastructure

The rapid proliferation of AI workloads has created an urgent requirement for increased bandwidth and interconnect density. Broadcom’s new DSPs are designed to tackle the challenges posed by optical interconnect power limitations, which can hinder the scalability of AI clusters. The Sian3 and Sian2M solutions promise not only to enhance performance but also to optimize costs for next-generation AI infrastructure.

The Sian3 DSP, manufactured using advanced 3nm technology, boasts the lowest power consumption in the industry for 800G and 1.6T optical transceivers utilizing single-mode fiber (SMF). Building on the success of its predecessor, the Sian2 DSP, the Sian3 offers over a 20% reduction in power usage for both electro-absorption modulated laser (EML) and silicon photonic (SiP) based 1.6T modules. This level of power efficiency is crucial as AI systems demand more from their underlying infrastructure.

Complementing the Sian3, the Sian2M DSP is tailored for 800G and 1.6T short-reach multi-mode fiber (MMF) links in AI clusters. By integrating Vertical-Cavity Surface-Emitting Laser (VCSEL) drivers and leveraging Broadcom's proven 200G VCSEL technology, the Sian2M opens new avenues for performance and efficiency. This innovation builds upon Broadcom’s impressive track record, having successfully deployed over 50 million channels of 100G VCSELs in AI networks.

Broadcom’s Sian3 and Sian2M DSP PHYs, when combined with its expansive portfolio of 200G/lane lasers, enable module developers to swiftly respond to the growing demand for 200G optics in AI applications. The company's 200G EML and photodetector (PD) products are currently in volume production, ensuring that customers benefit from the quality and reliability necessary for advanced AI optical interconnects.

Vijay Janapaty, Vice President and General Manager of the Physical Layer Products Division at Broadcom, emphasized the significance of these innovations: “Broadcom's Sian family of DSP PHYs is foundational to the low-power, high-bandwidth optical connectivity needed for AI/ML clusters.” He further noted the substantial power reductions achieved with the new products, underscoring their role in facilitating the scalability of AI clusters to meet growing demands.

According to Bob Wheeler, Analyst at Large at LightCounting, the shift towards AI infrastructure is expected to drive tremendous growth in PAM4 DSP shipments. He projected that by 2028, the demand for 1.6T optical transceivers could surpass $1 billion in PAM4 DSP consumption, highlighting the emerging market for these technologies.

Broadcom is currently sampling the Sian3 (BCM83628 and BCM83820) and Sian2M (BCM85834) to early access customers and partners, with production of the Sian3 set to ramp up in Q3 2025. This strategic introduction positions Broadcom to lead in the evolving AI infrastructure landscape.

Richard Huang, CEO of Eoptolink Technology, expressed enthusiasm about the integration of Broadcom’s DSPs: “By combining these advanced DSPs with our own engineering expertise, we are driving innovation across the ecosystem—enabling scalable, high-density optical connectivity that meets the evolving demands of next-generation AI infrastructure while lowering total cost of ownership.”

As Broadcom continues to innovate in this rapidly growing space, the Sian3 and Sian2M DSPs stand out as pivotal technologies poised to enhance the capabilities of AI and ML clusters, setting the stage for the future of high-speed, energy-efficient connectivity.