Summary
- QPT says its qMicroModule IBC converts 800V DC rack power to a 6V intermediate supply.
- The company claims up to five times the power density of current converter designs.
- QPT plans to license the architecture to semiconductor and power-system partners rather than manufacture every end product itself.
Cambridge power-electronics company QPT has unveiled an intermediate bus converter aimed at the 800V DC architectures being developed for next-generation AI racks, targeting the growing amount of rack space and electrical equipment required to deliver power to accelerators.
QPT says its qMicroModule IBC is designed to convert an 800V DC rack supply to a 6V intermediate bus in a single stage before power reaches the processors’ point-of-load voltage regulators.
The company claims the architecture can achieve up to five times the power density of current 800V converter designs. That performance claim has not yet been independently demonstrated in published third-party testing and should be treated as a QPT specification rather than verified operating performance.
The product is being introduced as AI infrastructure suppliers prepare for rack architectures with much higher total power. NVIDIA has publicly described an industry shift towards 800V DC distribution for future megawatt-scale racks, intended to reduce conductor size and the amount of conversion hardware needed to move large amounts of power through a rack.
QPT is trying to shrink the conversion stage
QPT argues that the intermediate conversion stage risks becoming a physical bottleneck because conventional resonant converters gain less from higher switching frequencies as transformer and switching losses increase.
Its alternative uses a hard-switched GaN architecture operating at multi-megahertz frequencies. The company says two modules can be stacked so each handles about 400V of the 800V input, allowing the first design to use established 650V GaN devices while leaving a route to higher-voltage components later.
QPT says the two-module arrangement can deliver roughly 5kW. It attributes the design to a combination of technologies including its ZEST transformer, an energy-harvesting network intended to recover switching energy, and a control system that adjusts the converter cycle by cycle.
Those claims build on power-electronics work the company has already demonstrated in another application. QPT’s MicroDyno motor-drive platform uses a 1MHz hard-switched GaN drive with its qControl technology. The qMicroModule applies the same broad high-frequency switching approach to data centre power conversion.
The company also says fast cycle-by-cycle control allows the converter to respond quickly to sudden AI load changes, reducing the amount of bulk capacitance required elsewhere in the power system and allowing rapid shutdown when a fault is detected.
Rack space is becoming part of the power problem
The attraction of 800V DC is not simply electrical efficiency. At megawatt rack scale, delivering current at conventional low voltages requires large conductors, busbars, conversion equipment, and supporting components. Raising the distribution voltage reduces current for the same power and can therefore reduce copper and physical volume.
That does not eliminate conversion; it moves the engineering challenge closer to the compute. The equipment stepping 800V down towards the low voltages used by processors has to handle large power flows inside an increasingly crowded rack.
QPT is positioning power density as the central metric. James Cannings, chief executive of QPT, said: “The whole industry agrees the AI rack is moving to 800 volts. The real question is how you convert that power without giving up the space the processors need.”
The company is not proposing to own the entire manufacturing chain. Instead, it is opening the architecture to semiconductor and power-system companies through licensing and lead design partnerships, with the intention that partners incorporate the IP into their own products.
Rob Gwynne, QPT co-founder and chief technology officer, said: “Resonant converters run into a wall as you push them to higher frequencies and higher power. Ours keeps scaling: double the switching frequency and you roughly double the power density, with no redesign.”
That scaling claim will be one of the important points for partners to validate. The economics of the design will ultimately depend on conversion efficiency, thermal performance, electromagnetic compatibility, reliability, component availability, and cost under sustained rack-level operation.
QPT has also identified its qAttach die-attach technology as a route to greater thermal headroom in later generations. For now, the significance of qMicroModule is less that it has displaced incumbent converters and more that the 800V transition is creating a new engineering contest around how little rack volume power conversion can occupy.
