What is a power sidecar in AI data centre architecture?

A rack-adjacent object that converts an existing 480 VAC-class facility feed to ~800V DC (bipolar per OCP Diablo 400 or unipolar per LVDC variants) and hands that DC to the compute rack via a busbar drop. It pulls AC-DC conversion and battery ride-through out of the compute rack so the rack is free for silicon.

What is the anchor reference product for the 800V DC power sidecar?

Delta 660 kW in-row: six 110 kW shelves, each with 80 kW BBU using aluminum-capacitor energy storage, powered by 18.5 kW AC/DC PSUs. Delta separately ships a 1RU 90 kW 800V-to-50V DC/DC shelf and 1 MW-class in-row systems.

What is the conversion boundary between sidecar and compute rack?

Whether the sidecar hands ~800V DC directly to the rack (Option A, high-voltage direct) or steps down to 48V inside the sidecar (Option B) is the strategic architectural fork. At 1 MW, Option A carries ~1.25 kA line current; Option B implies ~20.8 kA between sidecar and rack, which materially constrains the practical design envelope for blind-mate connectors and rack interconnects.

Is native 800V one topology?

No. OCP LVDC covers 350/700V bipolar TN-S with distributed midpoint, 350/700V bipolar TN-S without midpoint, 350/700V bipolar IT, 700V unipolar TN-S, and 700V unipolar IT. Grounding, protection, connector requalification and SiC device class differ across each configuration.

Where does conversion value migrate during the 800V transition?

Each transition removes or reshapes a conversion market and concentrates value in the stages that remain. In-chassis PSU value was displaced by the sidecar. Sidecar AC/DC value can migrate to facility SST vendors under fast native-800V. Rack DC/DC (Vicor, MPS, Navitas, EPC) survives all three stacks and concentrates further. Where value migrates during the transition is the investable question.

The 800V DC Power Sidecar: Anatomy, Conversion Boundary, and Value Migration

24 September 2026 · 29 min read

The 800V DC Power Sidecar. Three-stack diagram showing legacy rack-integrated, sidecar today, and native 800V facility architectures.

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