Datacenters are in big disruption with AI proliferation, introducing very fast product cycles. Power consumption at the xPU is increasing dramatically (multi-kW), bringing the total power in the rack up to several hundreds kW to 1MW.

For this reason, conventional architecture of power distribution inside the rack, based on 48V intermediate Bus generated from the AC main, needs to be modified to manage this dramatic increase of power. Current structure of the rack and architecture cannot manage the power increase without incurring in huge distribution losses.

A higher Voltage DC Bus is getting introduced by the Hyperscalers, and supported in R&D by the OEMs and PSU suppliers. This will be generated in an external side-car rack starting from the main AC, while the computational rack will be supplied by this voltage and will contain all the GPUs, or TPUS required to increase the computational performance of the AI infrastructure. The new isolated topologies involved in this high Voltage DC Architecture will require many high voltage switches, especially GaN will be extremely useful, since of the capability to switch extremely fast, and as a consequence enable a smaller size and high power density required by the huge power level of these new Racks. On the low voltage side to generate the intermediate 48V to reuse the existing ecosystem, both Silicon MOSFETs or GaN HEMT can be alternatives to achieve the performance and size requirement.

Other challenges have to be resolved also at lower voltage, where the current required by the GPU will also increase, with values that trend to a few kW. This requires to deliver the power to the load in unconventional ways, with vertical delivery, from the opposite side of the SoC, in the aim to reduce distribution losses. This vertical power delivery (VPD) can be implemented by discrete solutions, or more integrated modular approaches to reduce size and parasitics, integrating inductors and capacitors together with active elements. Renesas is able to supports all these new architectural elements, leveraging its GaN and Si switches portfolio, together with digital controllers for IBC and Multiphase, drivers, and digital and analog PoL and BMS controllers.