SiC MOSFETs, SBDs substitute silicon IGBTs at higher voltages

Article By : Majeed Ahmad

Silicon carbide (SiC) serving higher voltages and available in die, packaging and module formats is pushing barriers in power designs.

Silicon carbide (SiC) devices serving higher voltages are now available in die, package, and module formats as an alternative to silicon IGBTs while pushing design barriers with lower RDS(on) and higher current ratings. Take, for instance, Microchip Technology, which has unveiled three SiC MOSFETs and two Schottky barrier diodes (SBDs). These devices operate at 3.3 kV and aim to serve traction power units (TPUs), auxiliary power units (APUs), solid-state transformers (SSTs), industrial motor drives, and energy infrastructure solutions.

A 3.3 kV SiC MOSFET offers RDS(on) as low as 25 mῼ at 104 A, while a 3.3 kV SBD features a current rating of up to 90 A. These components are also available in low induction modules as well as with features and tools that help developers configure and customize SiC devices at the system design level. Additionally, Microchip offers gate drivers and parts like MCUs and touch sensors to complement the system approach and speed up the time to market.

Figure 1 SiC devices are considered highly suitable for the EV systems such as external charging stations, onboard chargers, DC-DC converters, and powertrain/traction control solutions. Source: Microchip

“We are introducing a new class of high-voltage products that address the performance and speed limitations of silicon IGBTs while ensuring faster switching and lower losses at higher power,” said Rob Weber, product line director for Silicon Carbide Solutions at Microchip.

He notes that the SiC adoption has picked steam during the past couple of years across a variety of applications, including generation of energy through renewables, distribution of energy through grid, and consumption of energy, most significantly, in the eMobility realm. However, while the SiC market has reached $1 billion in revenue, it’s still facing significant challenges in widescale adoption.

First and foremost, higher voltages lead to an increase in design complexity. Another problem is that there aren’t many suppliers of 3.3-kV power devices. “There are very few products at 3.3 kV, and the ones available have larger size and production becomes a challenge for these products,” Weber said. He added that a whole new development effort is required at higher voltages, where designers confront high-voltage spikes that can damage devices. “Then there are EMI issues as a key design consideration.”

Figure 2 The 3.3-kV SiC MOSFETs and SBDs are targeted at high-voltage designs serving eMobility, renewable energy/grid, and industrial and medical systems. Source: Microchip

That clearly shows how the traditional IGBT markets are gradually moving toward SiC devices that offer lower RDS(on) and higher current ratings, breaking new barriers in power electronics. And the fact that chipmakers like Microchip are consolidating SiC efforts across die, discrete and module power devices mark further inroads for this wide bandgap semiconductor.

This article was originally published on EDN.

Majeed Ahmad, Editor-in-Chief of EDN and Planet Analog, has covered the electronics design industry for more than two decades.

 

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