New app targets sharing plugs for EVs
Dow Kokam to provide Li-ion packs to Motiv Power and ZeroTruck for medium-duty electric commercial vehicles (correction)

Transphorm introduces Gallium Nitride diode; >99% efficient DC-DC boost converter

At the Applied Power Electronics Conference (APEC), Transphorm Inc. announced the availability of its first product: power diodes based on its patented, high-performance EZ GaN (gallium nitride) technology. Transphorm says that its solutions cut energy waste by 20% and simplify the design and manufacturing of a wide variety of electrical systems and devices, including motor drives, power supplies and inverters for solar panels and electric vehicles.

At APEC, startup Transphorm Inc. is showcasing a GaN-based, dc-to-dc boost converter running at more than 99% efficiency.

Energy loss that occurs during power conversion is equivalent to the daily output of 318 coal plants, and costs the US economy $40 billion per year. To tackle that problem, Transphorm is commercializing a high-voltage normally off GaN solution. The company’s GaN-based power converters are designed with 600 Volt transistors and low loss power diodes, will come in industry-standard packages, and are designed for optimum high-frequency switching, lowest loss and highest efficiency.

It is critical to realize high performance under high voltage switching operation that is required in real applications. Transphorm’s Total GaN-based Boost Converter operating at over 99% efficiency at 400 Volts demonstrates this for the first time.

—Primit Parikh, President of Transphorm

Transphorm is an ARPA-E funding awardee, under the Agile Delivery of Electrical Power Technology (ADEPT) program. (Earlier post.) Its ARPA-E project seeks to enable compact motor drives and grid-tied inverters operating at high power (3-10 kW) with efficiency greater than 96%. Transphorm is developing the first hybrid multichip power modules for inverters and converters operating at high frequency (1 megahertz), using low-loss ultra-fast GaN-on-silicon power switches that are normally in off mode.

Transphorm is taking a vertical integration approach, Parikh said in an interview with GCC at last week’s ARPA-E Energy Innovation Summit: it makes the material, fabricates the switches, designs the circuits and designs the application-specific modules. By using a proprietary EZ-GaN platform, Transphorm can reduce power system size, increase energy density while reducing overall system cost. This design uses fewer components, minimizes snubbers and filters, simplifies module packaging, and enables high-frequency design by reducing transients.

Transphorm is initially targeting three main markets for its GaN power electronics, Parikh said: IT and power supplies (e.g., data centers); photovoltaic inverters; and motion control (i.e., motor drives). Eventually, Parikh said, Transphorm will tackle the hybrid and EV market, for which it is well-suited; GaN operates well at high temperatures.

Transphorm is currently working with its first-generation GaN material; Parikh sees being able to deliver a 5-10x improvement on that with coming generations.

Our goal is to build [Transphorm] to be a legacy company.

—Primit Parikh




It is evident that electronics associated with electrified vehicles will come close to being 100% efficient versus about 25% for mechanical ICE motors and drive trains.

Future e-storage units (batteries and/or super caps) and wireless chargers may reach 95+% within 10 to 15 years.

Overall e-vehicle efficiency may be about 4 to 5 times current ICE + mechanical drive train vehicles. That could be enough to convert many deniers.

Dave R

This is huge!

Typical PV inverter: 95% efficient.
Typical EV charger: 95% efficient.
Typical EV inverter for power: 95% efficient.

So now that 1000W of power on your roof ends up only getting about 850W to the motor or about 85% overall efficiency (ignoring chemical charge/discharge losses in the battery).

But if all those items could be made at 99% efficiency - that gets us to 97% overall efficiency - or an overall improvement of about 13%.

Now multiply this across the grid - computer power supplies - lighting - etc. In many applications this will also significantly reduce cooling needs providing a double benefit. Even in areas where heating is needed, you can substitute resistance heating with heat-pumps - typically a 3:1 efficiency improvement.

Now how long before they start shipping in quantity and we start seeing products with them integrated?

Bob Wilson

I would be much happier if I could see a datasheet for a part or the technology. "Contact us" doesn't even come close.

Bob Wilson


"Transphorm introduces Gallium Nitride diode; >99% efficient DC-DC boost converter"

Without saying, a product introduction must include specifications, prices, and public deliveries.

Otherwise, it sorta seems like the beginning of a decade of EEStor super-capacitor announcements.

Henry Gibson

We do not need more efficiency for automobiles because drives insist on wasting power for speed. Why have a 99 percent efficient motor drive if you are wasting half the power to drive at 120 km/hr.

The very high speed trains in France are mostly nuclear powered.



And so could be 240 M vehicles in USA.


120 km/hr is slow. Going fast is no issue if low drag cars like Aptera etc were the standard.

Henry Gibson

Even low drag cars would also be much more efficient if driven at lower speeds. ..HG..

The comments to this entry are closed.