When it comes to power process technologies, one size does not fit all

Power electronic system and circuit designers have more choices in power process technologies. Silicon-based devices continue to evolve, but there is also an increasing option to use wide-bandgap material technologies such as gallium nitride (GaN) and silicon carbide (SiC).

With the diversity of today’s electronic systems and applications, you need these options at your fingertips. Each technology has its strengths, and it’s imperative to understand the trade-offs in efficiency and operating characteristics in order to select the most appropriate process technology for your application.

Silicon is the most widespread and least-expensive power semiconductor material. Several innovative developments in process and device technology have helped increase the power ratings for silicon devices. Some examples of high-power silicon devices include the gate-controlled thyristor, insulated gate bipolar transistor (IGBT) and super-junction metal-oxide semiconductor field-effect transistor (MOSFET).

Silicon devices cannot process large amounts of power while simultaneously switching very fast, however, making the material less efficient in power conversion and resulting in heavier and bulkier solutions.

These challenges facilitated the development and subsequent rollout of GaN- and SiC-based devices. As shown in Figure 1, the wider bandgap and other electronic properties of GaN and SiC material enable devices that can switch higher voltages at higher switching frequencies. This is important for data centers, automobiles, smart factories, the smart grid and more. Power devices based on GaN and SiC are ultimately more efficient, resulting in smaller and lighter systems than those that are silicon-based.

Figure 1: Power technologies and position relative to power levels and frequency

GaN is an excellent choice for high-density applications below 700V, such as telecom, enterprise servers, power supplies, motor drives and photovoltaic (PV) inverters. SiC is more suitable for higher-voltage and higher-power applications. These technologies will likely drive the future of high power, with an increase in overall density and weight efficiencies. As wide-bandgap technologies mature, they will also become more cost-competitive with silicon.

The bottom line is that the landscape for power systems is changing. My new white paper outlines the overlap between the technologies and explains that no single power transistor type is the hands-down winner in every situation. The market will demand all options.

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