Factorized Power Architecture Delivers Maximum Efficiency and Density with Design Flexibility


VTM Curent Multiplier and PRM Regulaor

In the drive to reduce distribution losses and improve overall system efficiency and density, power architectures have evolved from centralized power architecture (CPA) to distributed power (DPA) and, more recently, to intermediate bus architectures (IBA). Lately, though IBA became the preferred choice to tackle the widespread proliferation of IC loads across system boards. However, IBA may not be the optimal architecture as electronic systems continue to migrate toward lower voltages and higher currents.

As device loads, such as state-of-the-art microprocessor chips, logic ICs and memory modules, move towards sub-1 volt with current consumption of more than 100 amperes and transient responses in nanoseconds, traditional power architectures like the IBA are approaching a dead-end.  To surmount the limitations of traditional distributed architectures, and meet the new emerging system requirements of higher power density at lower output voltages with higher load currents and efficiencies requires a very different approach.

For addressing these new challenges in modern and future electronic systems, Vicor engineers have developed Factorized Power Architecture®. FPA® employs advanced topologies such as Sine Amplitude Converter™ in a modular product line, which offers a minimum 5X increase in efficiency and higher power density and adds a level of incomparable flexibility for designing optimal solutions for performance-critical applications.IBA vs. FPA

By separating the classic function of DC-DC converters and “factorizing” regulation, isolation and voltage transformation into flexible, high-performance VI Chip building blocks, FPA significantly cuts distribution and interconnect losses to improve power conversion efficiency. The modular PRM® regulator and the VTM® current multiplier enhance the power density of the solution with greater than 1 MHz response speed. The high power density enables more function in the same space and the design of a more powerful system with a smaller and lighter power supply.

In an FPA system, the PRM generates a controlled bus voltage called “factorized bus”, and the VTM transforms the factorized bus voltage to deliver an isolated voltage to the point-of-load (POL), regulated by the upstream PRM. Because the VTM, a POL device of the FPA, does not perform a regulation function, its  essential conversion function is current multiplication or voltage division by a factor of K. That means, the VTM can deliver energy to the load throughout the entire conversion  cycle or offer 100% transformation duty cycle. By relocating the regulation function to the upstream PRMs, the VTMs are not limited by the inductive inertia and can respond virtually instantaneously to a changing load.

The PRM uses a patented ZVS buck-boost regulator control architecture to realize high efficiency step-up /step-down voltage regulation. The efficiency is maximized when the output voltage is close to the input voltage. The PRM operates at a typical fixed operating frequency of 1 MHz (1.5 MHz max.) and can be paralleled to achieve increased output power.

PRM Regulator key features include:

  • input ranges of 18-36 V and 36-75 V
  • power up to 400 W
  • power density up to 1100 W/in3
  • efficiency up to 97%
  • 1.5 MHz switching frequency
  • up to 125 °C operation

The VTM, which is a fixed-ratio DC-DC Sine Amplitude Converter®, offers wide voltage range input with high efficiency voltage transformation using proprietary zero current switching-zero voltage switching (ZCS-ZVS).

The VTM Current Multiplier key attributes can be summarized as:

  • input range compatible with 48 V and 24 V PRMs
  • power up to 400 W or 100 A
  • power density up to 1,095 W/in3
  • efficiency up to 96%
  • isolation to 2,250 Vdc in 1.1 inch square package
  • low power dissipation at point-of-load
  • low output impedance enabling fast transient response

FPA can be configured to deliver an optimal power solution for many performance-critical applications. FPA is a whole system approach that focuses on the design of smaller, cooler, quieter systems with energy cost reductions and high performance. Here’s a previous post about Vicor’s Intel VR 12.0 compliant solution.