Power-conversion ICs target 48V data centre architecture

ST has implemented direct digital power conversion from 48V by developing a family of ICs to support the complete range of data centre power-conversion applications. The direct digital power conversion eliminates intermediate conversion stages to minimise power loss in data centres from power distribution and reduce space, cooling requirements and cost. The ICs are fully compliant with Intel's VR12.5 (Haswell and Broadwell), VR13 (Skylake) and DDR3/4 voltage-regulation specifications, and all FPGAs and ASICs for data centre applications.

The three chips (STRG02, STRG04 & STRG06) together with ST's low-voltage StripFET power-MOSFET family, assure robust and highly-efficient system operation at input voltages from 36 to 72V, with output voltages between 0.5 and 12V. These specifications confirm best-in-class power efficiency of over 97% at 12V/500W and high system bandwidth using minimal PCB space.

The STRG02 is a secondary-side controller that features predictive zero-voltage switching and zero-current switching control and while permitting power to be sunk during falling adaptive voltage scaling.

The STRG04 is a 60V full bridge that provides driver capability to a wide range of external MOS- (Metal Oxide Semiconductor) or GaN-based switches at high frequency. The chip supports a wide input-voltage range to substantially simplify the power-delivery chain, including allowing direct connection of the battery backup, which enables higher system availability.

The STRG06 is a scalable digital power controller that for the 48V data centre server architecture to manage up to six converters in parallel, supporting output power from 50 to more than 300W. The STRG06 also implements energy proportional control, adaptive interleaving, current sharing and a complete set of the extensive PMBUS commands for fault management, primary- and secondary-side telemetry data and safety system for traceability and analysis, to operate as a data centre black-box recorder.

Matteo LoPresti, Group Vice President and General Manager, Analog, STMicroelectronics, commented: "This 48V architecture is ideal for ultra-high-efficiency data centres in significantly reducing the total cost of ownership. ST is already in volume production and supporting this next-gen application with our unique isolated resonant-power converters, demonstrating that this solution offers industry-leading power efficiency, along with outstanding scalability and flexibility."

The three ICs are available now and ST offers a demo board to showcase the advantages of the 48V architecture and its three-chip solution.