In the world of power conversion, silicon is running out of gas – and gallium nitride technology is on the move. Gallium Nitride provides faster switching speed, smaller size, higher efficiency, and, now, lower cost. Aside from the many benefits of GaN, it’s important to understand the Gallium Nitride market, its various applications, and the ever-developing future of GaN. Read on to discover how GaN is changing the way we live.
Can Gallium Nitride Replace Silicon?
The initial adopters of GaN-based power transistors and integrated circuits were those applications taking advantage of the ability of GaN-on-Si transistors to switch about 10 times faster than MOSFETs and 100 times faster than IGBTs. Applications such as RF envelope tracking for 4G/LTE base stations and light detection and ranging (lidar) systems for autonomous cars, robots, drones, and security systems were the first volume applications to take full advantage of GaN’s high-speed switching ability.
Since these early applications, the production volumes have grown, and now GaN power devices are at a point where the prices are equivalent to MOSFET components of similar on-resistance. This has enabled more traditional applications, such as 48 V DC/DC conversion for data centers and computing, BLDC motors for emobility, robotics, drones, and high-volume automotive applications to adopt gallium nitride-based solutions.
What Are the Advantages of Gallium Nitride (GaN) over Silicon Carbide (SiC)?
Both GaN-on-silicon and Silicon Carbide (SiC) are wideband gap semiconductor solutions capable of sustaining higher voltages, higher frequencies, and more integrated products than silicon alone. These factors are leading to the widespread adoption of silicon carbide and gallium nitride across the electronics market. SiC is ideal for high-voltage applications at 900 V and above. GaN-on-silicon ably addresses applications at 700 V and below. The battleground area among GaN, SiC, and silicon IGBTs is those applications between 700 V – 900 V where most electric drives for electric vehicles are designed.
Gallium Nitride Market Outlook
Market research firm Yole Développement estimates that the power gallium nitride devcie market will grow from $126 million in 2021 to $2 billion in 2027, a compound annual growth rate (CAGR) of 59%.
A significant portion of this growth will be fueled by the consumer market including fast chargers, Class-D audio, power banks, and time-of-flight sensors in smart phones and tablets. In these applications GaN provides higher power density, better thermal performance, and smaller/lighter solutions.
The convergence to a 48 V power system in both high-power density computing and automotive DC-DC converters is driving growth in both the telecom/datacom and automotive/mobility segments. 48 V systems reduce power consumption in data centers and the demands of these systems favor GaN over silicon.
As the adoption of renewable energy accelerates, manufacturers of solar microinverts, optimizers, and energy storage systems are increasingly designing with GaN for higher efficieny, higher power density, and increased reliability. Several manufacturers, including BRC Solar and Solarnative, have announced GaN-based solutions.
How GaN Supports New Applications
Data Center Servers
The growth of the cloud is forcing a corresponding growth in data centers, which are major consumers of energy. One means of reducing the energy loss is to eliminate an entire stage of power conversion when funneling power from the input of the data center to the final point of load. Commonly, power is converted in two stages – from 48 V on the backplane to 12 V for distribution on the processing boards and ultimately to around 1 V at the actual point where the power is put into use powering the digital chips. With the high switching speed, small size, and higher efficiency of GaN, power supply designers now have the capability to convert directly from 48 V to the range of 1 V needed at the point of load without the intermediate stopping point at 12 V. The potential energy savings with this single-stage architecture is huge, given the rapid expansion of computing power and data centers needed to support the cloud infrastructure.
Autonomous Vehicle/Augmented Reality
One GaN application that is quite exciting and provides a glimpse into the future is self-driving, or autonomous, cars. Looking closely at the image on the right, you will see that it is a lidar (light distancing and ranging) system atop the vehicle that provides the “eyes” for the vehicle. The lidar device rapidly fires a steered beam of light and records the amount of time it takes for the beam to return as well as the direction in which it was fired, thus creating a 360-degree, three-dimensional image of what is surrounding the vehicle. The faster the laser beam can be transmitted, the higher the resolution of the mapping or location objects the lidar detects. At the core of the lidar system is where GaN technology plays a vital role; it enables the laser signal to be fired at higher speeds than a comparable silicon component.
Similar lidar technology is being designed into augmented reality headsets, providing users with three-dimensional real-time images. Beyond their use for games, which we are seeing now, augmented reality also gives soldiers the ability to see the enemy at a distance, as if they were standing in front of them. The image from behind enemy lines is being taken with a lidar-bearing drone. For civilians, augmented reality headsets could be used to access three-dimensional real-time images of anywhere in the world.
Also using lidar are the most advanced robots. These robots use lidar as their “eyes” because lidar is fast, precise, and requires less computation to create a three-dimensional digital image.
Radiation Tolerant and Space
Gallium nitride devices are in space. This is an inevitable area for many GaN applications since gallium nitride is inherently radiation tolerant. Unlike silicon, where special fabrication techniques and special packaging are needed to shield semiconductors from the effects of radiation, GaN’s natural properties make it relatively immune to these harmful rays.
GaN transistors are used in ion thrusters, to convert power from the satellite solar panels, in ruggedized high-precision BLDC motors for driving the reaction wheels used by small CubeSats, in the robotics and automated instrumentation used in space missions, and for ranging applications using lidar. In addition to its ability to survive in a harsh environment, the small size and high efficiency of GaN devices make them very attractive for use in space applications.
The growing demand for electro-mobility (eMobility) requires highly efficient and compact motor drives. GaN FETs and ICs enable the design of inverters that increase motor efficiency while reducing size, weight, and cost. This enables motor systems that are smaller, lighter, less noisy, and have more torque, more range, and greater precision. These advantages produce smaller, lighter, more efficient motor systems for electronic bikes and scooters, and for personal robotics such as vacuums and drones.
To accelerate the adoption of renewable sources of energy, more efficient conversion, increased capacity of energy storage, and lower cost must be achieved without sacrifice to long-term reliability. GaN-based power solutions enable solar micro-inverters, optimizers, and the energy storage systems used for solar power to increase efficiency and reduce size and cost while providing unmatched robustness.
GaN has a major role in medical applications, and we have only just begun to discover and implement innovative solutions. Wireless power sources using GaN transistors can be used to charge implantable medical devices such as heart pumps and pain scintillators needed for patients with diabetes, thus eliminating the need for wires to protrude from the body -- wires that are prone to causing infection.
Another good example is the use of GaN components in an extremely small x-ray machine that fits in the size of a pill. The pill is used to perform colonoscopies. Once ingested, images are taken as the pill travels through the digestive tract. The digital information from the x-ray device is transmitted wirelessly to a receiver outside the patient’s body for evaluation by a physician. To the patient, this means an easier examination. To the physician, it means higher-resolution imaging of the colon. In this application, GaN’s extremely small size and high switching speed are key for powering the x-ray device within the pill.
MRI machines are also taking advantage of GaN’s superior performance to obtain 10 to 100 times higher resolution so cancers and other maladies can be discovered earlier, more accurately, and less expensively.
The emergence of wireless power is another recognizable application enabled by GaN. No need for wires any longer – we can cut the cord. Wirelessly charged cell phones are on the market and tablets, computers, and even medical instruments on mobile carts are not far behind. The automobile center console will become the source for not just wirelessly charging the phone, but will also soon be the source for charging the car’s entire infotainment and navigation systems. Ultimately, the entire home can be equipped with transmitters and repeaters that will wirelessly power the lights, TV and other household appliances. GaN transistors are supporting this exciting, rapidly emerging application…and changing the way we live.
The Future of GaN
GaN as a technology is merely at its beginning, only being commercially available in the past few years compared to more than the 70 years that silicon devices have been around. And, as shown, applications taking advantage of GaN’s superior efficiency, switching speed, and size have already emerged. The future is promising as GaN technology climbs the learning curve, its end-use becomes more widespread, and performance improves year after year.
How Can GaN Be Used?
Aerospace and Defense