SiC solutions provide high efficiency and high reliability for power conversion systems

Lan Jiantong, vice president of marketing for Asia Pacific at Fairchild Semiconductor, told reporters that in order to enhance these key design performances in the fields of renewable energy, industrial motor drives, high-density power supplies, automobiles, and underground operations, the complexity of the design will increase, and the overall system cost will also increase. To help designers solve these technical problems, Fairchild started with the use of new materials. Recently, Fairchild launched a silicon carbide (SiC) technology solution that is very suitable for power conversion systems.

Lan Jiantong said that the first batch of products released in Fairchild Semiconductor's SiC portfolio is an advanced SiC bipolar junction transistor (BJT) series, which can achieve high efficiency, current density and reliability, and can smoothly operate at high temperatures. By utilizing transistors with excellent efficiency, Fairchild Semiconductor's SiC BJT achieves higher switching frequencies because of lower conduction and switching losses (30%~50%), which can achieve up to 40% output power improvement in systems of the same size.

SiC BJTs support the use of smaller inductors, capacitors and heat sinks, reducing overall system costs by up to 20%; they promote higher efficiency and excellent short-circuit and reverse-bias safe operating areas, and will play a significant role in optimizing power management in high-power conversion applications.

At the same time, Fairchild Semiconductor has also developed a plug-and-play discrete driver circuit board (15A and 50A versions). As part of a complete SiC solution, when used with Fairchild Semiconductor's advanced SiC BJT, it can not only increase the switching speed while reducing switching losses and enhancing reliability, but also enable designers to easily implement SiC technology in practical applications. Fairchild Semiconductor also provides application guides and reference designs to help customers shorten design time and speed up time to market. The application guide allows designers to obtain other support necessary for SiC device design; the reference design helps to develop a driver circuit board that meets specific application requirements.

Lan Jiantong said that compared with silicon materials, SiC has a wide bandgap that is three times that of silicon materials, a high breakdown electric field that is 10 times that of silicon, a high thermal conductivity and high temperature stability that are also three times that of silicon, and a very low leakage current (<10μA). The advantages of SiC in transistors are mainly reflected in the efficiency of more than 98%, a faster switching speed (<20 ns), which is 3 to 4 times faster than IGBT, and stable and reliable performance.

Lan Jiantong believes that 2015 will be a turning point in the development of SiC, and SiC will play a leading role in the application of power devices. In the next ten years, this market share can increase 20 times. Hybrid vehicles and electric vehicles are the main driving forces, and the demand for SiC in the motor drive, wind power, solar energy and other markets will grow rapidly. Although the price of SiC is more expensive than IGBT at present, with the improvement of SiC process technology, the price will drop, and the yield will be greatly improved, and the popularity of applications will also increase, especially in the 5kW application field, where SiC has great room for development.

It is understood that Fairchild's future plan for SiC BJT drivers is to launch SiC BJT driver solutions (discrete) in 2013, SiC BJT driver ICs (version 1) in 2014, and SiC BJT driver ICs (version 2, balanced) solutions in 2015.