In the world of power conversion silicon is running out of gas and gallium nitride technology is on the move providing faster switching speed, smaller size, higher efficiency and, now, lower cost. GaN…is changing the way we live!
Autonomous Vehicle/Augmented Reality
One application that is quite exciting and provides a glimpse into the future is self-driving, or autonomous, cars. Looking closely, 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.
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 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.
Size matters. And a 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 track. 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, it means an easier examination and 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.
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. GaN has a major role in medical applications and we have only begun to discover and implement innovative solutions.
Telecommunications is another emerging application for GaN power conversion devices. As cell phone usage is coupled with the requirement to transmit exponentially more data due to the use of phones for business transactions, video, and games, more and more bandwidth is going to be needed – enter envelope tracking. With envelope tracking, the amount of power required to send information tracks precisely with the carrier signal being transmitted doubling the efficiency of the base station at 4G data transmission rates, and tripling the efficiency at the anticipated 5G architectures. The ability of GaN to switch at ultra high speeds efficiently is the key factor making envelope-tracking systems for telecommunications possible.
Data Center Servers
The growth of the cloud is forcing a corresponding growth in data centers, which are major consumers of energy. One means for 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.
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 is 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, they are used to convert power from the satellites solar panels, and they are used for ranging applications using LiDAR. In addition to its ability to survive in a harsh environment, the small size and high efficiency of GaN device make them very attractive for use in space application.
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 its 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.
There is no doubt; GaN…is changing the way we live!