Semiconductor and its wide world are updating to advanced fabrication processes and wide bandgap semiconductors are of its kind. Among the wide bandgap (WBG) semiconductors, silicon carbide (SiC) and gallium nitride (GaN) is nowadays recognized as outstanding materials for the future of power electronics. In fact, owing to their excellent properties, they can guarantee a better energy efficiency in power conversion systems with respect to Silicon. Today, although several SiC and GaN devices have already reached the market, there are still many technical issues to be faced in order to fully exploit the enormous potential of these materials.
The impressive qualities of GaN and SiC have made them endearing to the industry insiders. GaN and SiC are designated wide bandgap (WBG) semiconductors based on the energy required to shift electrons in these materials from the valence to the conduction band. For silicon, this energy is 1.1eV; about 3.2eV for SiC; and 3.4eV for GaN. Those properties lead to a higher applicable breakdown voltage, which can reach up to 1,700 volts in some applications.
Silicon has been ruling the world of Semiconductors but power semiconductors based on GaN and SiC technologies may provide a path to efficient power supply across industrial environments, while also complementing the expansion of the renewable energy segment.
ELE Time’s correspondent Sheeba Chauhan had an insightful session with Francesco MUGGERI, Vice President, Power Discrete and Analog Products, Asia Pacific, STMicroelectronics. This article majorly covers emerging trends in Wide Band Gap Semiconductors and its current scenario in the industry.
ELE Times: What is the new Smart Power initiative based on GaN technology?
In addition to developing a complete range of discrete GaN transistors (or HEMT), there are essentially two approaches to smart Power. One is our MasterGaN-product-series approach, which combines Silicon-based gate drivers and basic control functions with the GaN transistor (or HEMT) in a single package/chip, which eases customer design. For both approaches a GaN technology placing the gate driver as close as possible to the switch shortens the connections and, in view of the high or very high-frequency operation involved, reduces noise and other design challenges. The second approach enables designers to realize monolithic integration exploiting the compatibility of the GaN technology with CMOS design rules. One example is the STi2GaN which includes solutions for On-Board Chargers, LiDAR for autonomous driving, bidirectional DC-DC converters, Class-D amplifiers, and power supply systems
ELE Times: How do SiC and GaN technologies drive innovation and efficiency in tomorrow’s power electronics?
The two technologies share unique physical properties that allow for a drastic reduction of losses, both conduction and switching, over the more traditional Silicon-based technology that translate into higher energy-conversion efficiencies. At the same time, they enable power density increases and, therefore, miniaturization.
ELE Times: How wide bandgap semiconductors are shaping the future of power electronics?
The new semiconductors bring benefits and advantages not only to conventional electronic systems based on silicon, but they also enable novel circuit topologies that intrinsically increase efficiency. Stricter design and regulatory requirements in reducing wasted power in a large variety of processes and associated environmental pollution will require the large-scale deployment of more efficient power semiconductors – and WBG semiconductors will meet those needs.
ELE Times: What are the latest power solutions for industrial and automotive applications that ST has to offer?
While ST still continues to improve “legacy” silicon products like super junction high-voltage MDmesh transistors and IGBTs, we have developed and now sell a complete line-up of SiC MOSFETs from 650V to 1700V that represent a good match for market requirements for photovoltaic inverters, storage systems, and factory automation. In electric vehicles, ST’s SiC products are already equipping electrified platforms with advanced components that are being used in inverters, on-board chargers and DC-DC converters as well as the charging stations being rolled out. In GaN, ST is introducing 650V transistors for high-volume power supply markets such as adaptors and chargers. Our development plans also include automotive products to enlarge the offer of SiC MOSFETs and diodes. All ST power transistors and diodes belong to the STPOWER offer.
ELE Times: What are the latest innovative SiC & GaN power solutions from ST that make industrial and automotive systems smarter and greener?
In SiC, ST is preparing to launch its proprietary 3rd-generation of SiC MOSFETs with increased performance. These advanced series bring lower on-resistance per unit area and improved switching performance and are therefore well suited to many industrial and automotive projects. For example, a full electric car equipped with these SiC MOSFETs will allow lighter electronic units and will contribute to greater mileage for a given battery pack, reducing “range-anxiety.” The same series can also be used to make more efficient solar inverters that can transfer more energy to the user for given patterns of sun radiation. And our new GaN transistors reduce the size of PC adaptors while also generating less heat, which as you know, is symptomatic of energy loss. So, they are much more efficient.
Sheeba Chauhan | Sub Editor | ELE Times
