Full Power, Reduced Size: GaN Adapters Offer Up to a 250% Increase in Power Density

26-03-2020 |   |  By Rob Coppinger

Gallium nitride (GaN) enables smaller, lighter, more efficient desktop AC-DC power supply series for portable products.

Gallium Nitride (GaN) is a wide bandgap semiconductor. When utilised within power supplies, GaN offers improved efficiency, decreased size, and reduced weight over traditionally used silicon. Losses in traditional silicon transistors have two categories, conduction and switching. Power transistors are a major contributor to power loss in a switching power supply. To stem these losses, the development of GaN transistors (replacing the older silicon technology) has been of particular interest to the power electronics industry. 

GaN shows significant advantages over silicon in key areas and these allow power supply manufacturers to significantly increase their efficiency. Switching losses occur during the transition between on and off states as the current flows through the transistor. For a given breakdown voltage, GaN offers less resistance and subsequent switching & conduction losses than silicon, and because of this GaN adapters can achieve efficiencies up to 95%. 

Gallium Nitride - Silicon’s Superior

As GaN devices have better thermal conductivity and withstand higher temperatures than silicon, the significant reductions in the overall size of the power supply possible due to these hardier transistors can reduce the need for thermal management components, like bulky heatsinks, frames, or fans. The removal of these internal components, as well as the increased switching frequency, allows for a power supply that is not only lighter but more compact as well.


The advantages of higher speed, low specific resistivity and low saturation switching for the transistors means they are expected to find many use cases within power electronics. As such, new power electronics’ system architectures, circuit topologies and packaging solutions are being investigated by industry to achieve and optimise the various system advantages offered by GaN.

CUI’s GaN AC-DC Desktop Power Adapters

Recognising the benefits of GaN technology, CUI Inc has launched its first GaN powered desktop adapters with the SDI200G-U and SDI200G-UD series.

The compact new power models (additions to CUI’s SDI product family) are 32% lighter than their non-GaN counterparts, offer 200 Watts of continuous power and are designed for a wide range of portable industrial and consumer products. The drop-in weight has seen a substantial reduction from 820 grams to 560g and the adapters offer increased switching frequency that has also allowed their volume to be reduced by more than half. This increases the power density from 5.3 Watts per inches cubed to 11.4 W/in3.

The CUI adapters for AC-DC power supply meet existing average efficiency and no-load power specifications mandated by the United States (US) government’s Department of Energy under the Level VI standard and the European Union’s (EU) CoC Tier 2 directive for universal input voltage ranges.

The SDI200G-U series offers a three prong (C14) inlet and the SDI200G-UD features a two prong (C8) inlet. Measuring as small as 5.91 x 2.13 x 1.3 inches (150 x 54 x 33 millimetres), the SDI200G-U and SDI200G-UD comply with UL/EN/IEC 62368-1 and 60950-1 requirements. 

gan power adapter

These desktop adapters feature up to a 250% increase in power density, no-load power consumption as low as 210 mW, and universal input voltage ranges of 90 to 264 Vac. The SDI200G-U and SDI200G-UD offer users a compact, efficient desktop adapter for applications where portable power and product aesthetic are a priority.

Please contact CUI with any GaN technology questions or product inquiries.


By Rob Coppinger

Rob Coppinger is a freelance science and engineering journalist. Originally a car industry production engineer, he jumped into journalism and has written about all sorts of technologies from fusion power to quantum computing and military drones. He lives in France.

Related articles