May 2020

16 POWER GaN www.Finepower.com Issue 2 2020 Power Electronics Europe www.power-mag.com A Technology Conquers Power-Hungry Applications Gallium nitride (GaN) power devices have opened many new applications since their commercial availability began in 2010. The superior switching speed of GaN devices and, as a result, their low switching losses, gave the starting signal for the development of new applications such as lidar (light detection and ranging) sensors and resonant wireless power. In the midst of a multitude of such innovative applications, a strong value chain with low production costs and extremely reliable products grew up. As a result, even more conservative, budget-conscious developers in cost-sensitive application areas, such as power supplies and the automotive industry, felt motivated to evaluate GaN power devices for their designs. Tobias Herrmann, FAE and Jieyi Zhu, Line Manager EPC at Finepower, Ismaning, Germany For a new technology to establish itself on the market, it must meet four criteria: It must enable new applications, be easy to use, be lower cost, and be highly reliable. Available GaN components today are 5 to 50 times better than state-of-the-art silicon solutions. This performance advantage has led to new applications that only became possible with GaN technology. One such application is lidar, a high-resolution sensing technology used for autonomous cars, augmented reality, industrial automation and drones. The second attribute that a new technology needs to establish itself is its ease of use. GaN-based power converters offer higher efficiency, higher power density and lower total system cost than Silicon-based alternatives. The ecosystem of supporting components such as gate drivers, controllers and passive components is growing continuously. Cost is equally important for a new technology to displace an entrenched technology. GaN transistors and integrated circuits are produced using processes similar to silicon power MOSFETs, have many fewer processing steps than MOSFETs, and more devices are produced per manufacturing run because GaN devices are much smaller than their Silicon counterparts. In addition, lower voltage (<500 V) GaN transistors do not require the costly packaging needed to protect their Silicon predecessors. This packaging advantage alone can cut the cost to manufacture in half and, combined with high manufacturing yields and and smaller device size, has resulted in the cost of a GaN transistor from EPC to be lower in cost than a comparable (but lower performance) Silicon power MOSFET. Finally, GaN components easily meet the reliability criterion: they not only pass the JEDEC standard tests for semiconductors, but in many cases also the more stringent qualification requirements of the automotive industry (AEC Q101). In addition, EPC’s eGaN® transistors and ICs in chip-scale packaging are free from the typical failure mechanisms inherent in traditional MOSFET packaging techniques. Entering conservative and cost- sensitive applications These superior properties are increasingly prompting developers in more conservative and cost-sensitive applications such as power supplies and automotive to take a closer look at GaN devices. An example of such an application is 48 V DC/DC converters. Such converters are used in many areas of the electronics industry. For example, the advent of 5G and the explosion of data for hyperscalers, cloud-based data centers, and artificial intelligence demand more power in much smaller form factors. Due to the significant improvements GaN offers in switching performance and size reduction, power supply designers are realizing that GaN FETs and ICs make higher power density and more efficient 48 V power supplies. Likewise, in the automotive industry, GaN transistors are becoming the power technology of choice for the design of compact systems for 48 V supply in hybrid, mild hybrid, and plug-in hybrid vehicles. They enable the development of lighter and at the same time more cost- effective systems. Why 48 V for cars? With the emergence of autonomous cars Figure 1: Line-up of EPC’s chip-scale GaN power FETs and ICs