Perfect layout What is the difference between Infineon’s silicon carbide product family?

In recent years, the third-generation semiconductor materials represented by wide-bandgap compounds such as silicon carbide (SiC) and gallium nitride (GaN) have attracted much attention, and major semiconductor manufacturers have increased their layout and investment. As the supplier with the highest market share in the global power device market, Infineon launched gallium nitride devices at the end of 2017, and launched eight 650V CoolSiC MOSFET devices in February this year, further expanding its silicon carbide product portfolio.

Advantages of Silicon Carbide

According to the market forecast of HIS, the market share of 650V SiC MOSFETs will be close to US$50 million in 2020, and the market share will reach US$160 million by 2028, with a compound annual growth rate of 16%. The main applications are power supplies, uninterruptible power supplies (UPS), electric vehicle charging, motor drives, photovoltaics, and energy storage, with the power segment accounting for the largest share.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

Traditional silicon has developed so far, and the market size is very large, but the compound growth rate of the market is only single digits. The compound annual growth rate of 650V SiC MOSFET is 16%, which is very impressive and attractive. “Infineon has accumulated more than 10 years in the field of silicon carbide, and the SiC diode has been iterated to the sixth generation. The silicon carbide products developed by Infineon can provide more advantages.” Infineon Technology Power and Sensing System Business Chen Qingyuan, senior marketing manager of switching power supply applications in Greater China, introduced.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

Chen Qingyuan summarized several advantages of silicon carbide devices: the band gap of silicon carbide is about 3 times that of silicon materials, the blocking voltage per unit area is about 7 times that of silicon carbide, the value of electron mobility is not much different, the thermal conductivity It is about 3 times, and the electron drift speed is also about 2 times. According to the performance of these physical properties, silicon carbide can run at higher voltages and achieve higher efficiency, enabling power devices to meet the requirements of light, thin, short, and at the same time have higher switching frequencies, thereby achieving smaller volumes. In addition, for designers and users, silicon carbide also has good heat dissipation performance, making the design work more handy.

How are 650V CoolSiC MOSFETs different?

Perfect layout What is the difference between Infineon’s silicon carbide product family?

At the end of February this year, Infineon launched 8 different 650V CoolSiC MOSFET products, with ratings between 27 mΩ and 107 mΩ, in two plug-in TO-247 packages, either with a typical TO-247 3-pin package, and also supports the TO-247 4-pin package with lower switching losses. Compared to all CoolSiC MOSFET products released in the past, the 650V series uses Infineon’s unique trench semiconductor technology, which ensures high device reliability, low switching losses and conduction by maximizing the physical properties of silicon carbide. pass loss. In addition, they feature the highest level of transconductance (gain), a threshold voltage (Vth) of 4V, and short-circuit robustness.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

In the design of power supply, in addition to performance, reliability should also be considered. Target markets such as communication power supplies usually have a service life of more than ten years, and servers and data centers will probably be 5 to 10 years old. Therefore, in addition to performance considerations, ruggedness and reliability cannot be ignored. Infineon has made various researches and optimizations on the reliability of silicon carbide products, making it more convenient both in use and design.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

The gate oxide layer is a design difficulty that affects its reliability. There are two mainstream manufacturing processes for SiC today, planar and trenched. The planar type requires a trade-off between performance and gate oxide reliability in the on state; the trench type is more likely to meet performance requirements without deviating from the gate oxide safety conditions. “Infineon’s CoolSiC MOSFET adopts the trench type. We have 20 years of research and development experience in the field of trench technology. With the trench design, we can maximize its performance.” Chen Qingyuan said, “We think grooved is the future.”

In order to prevent “misleading turn-on”, Infineon redesigned VGS to be greater than 4V, which can reduce the “misleading turn-on” caused by noise.

In some special topologies, such as the CCM totem pole topology, hard commutated body diodes are used. “The application of the totem pole is actually a bridge topology, which is very common in low-voltage power conversion, but in high-voltage power conversion, limited by the reverse recovery characteristics of some devices, it is generally difficult to operate in high-power situations. The structure of the totem pole is used to work.” Chen Qingyuan explained, “The reverse recovery speed of the silicon carbide material itself is particularly fast, much faster than the reverse recovery speed of the common silicon material. The main advantage of this structure is to increase the power. Density and efficiency.”

Perfect layout What is the difference between Infineon’s silicon carbide product family?

According to reports, the current 3kW PFC using totem poles can easily achieve (full load) 98% or even 98.5% efficiency under the input condition of 220 volts.

According to the application environment of the power supply, the rated voltage will exceed 650V when the power supply is unstable. The 650V CoolSiC MOSFETs are avalanche resistant, preventing device damage from improper use as well as damage to power tools.

In addition, compared with traditional silicon, some design considerations have also been made to relax the VGS voltage range. VGS can be turned off at 0V, and it will not go to negative voltage. Unlike gallium nitride to have a negative voltage, it will cause the burden of the entire circuit and also cause some pressure on the design.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

Comparing the physical properties of CoolSiC, CoolGaN and CoolMOS, it can be seen that at 25°C, the on-resistance of the three is the same; at 100°C, the on-resistance of CoolSiC is 26% lower than that of CoolGaN and 32% lower than that of CoolMOS. %. This shows that SiC is far more efficient than GaN and Si at high temperature, so it is especially suitable for high temperature application scenarios, which can reduce design costs.

Si, SiC and GaN, how to choose?

As the only company in the market that provides a full range of power products covering Si, SiC and GaN, Infineon can not only provide silicon carbide to meet different choices in different application fields, but also discuss with customers the most suitable best device. Chen Qingyuan believes that the three will always be in a coexisting relationship, and there will be no replacement in the future.

Perfect layout What is the difference between Infineon’s silicon carbide product family?

Silicon devices are suitable for applications ranging from 25V low voltage to medium voltage to 1.7kV; silicon carbide is suitable for applications from 650V to high voltage 3.3kV, with a wide range of applications, such as wind power, power supply for large data centers, etc.; gallium nitride is suitable for 80V~650V voltage range, high switching frequency applications.

In terms of cost performance, silicon is definitely the first choice; and gallium nitride is more suitable for the highest efficiency and highest power density, its price may not have the advantage of silicon, but efficiency and power density are irreplaceable; if you want to consider “easy to use” “Performance” as well as sturdiness and durability, silicon carbide is an excellent choice.

It is reported that the 650V CoolSiC MOSFET was just launched in February, and customers in Greater China have already mass-produced it. At the same time, several customers have placed orders one after another, mainly used in higher-end products. At the end of the year, new products will be launched one after another, and it will expand to more than 50 products in 2021.

In the face of the fierce competition in the silicon carbide market, Chen Qingyuan said that Infineon has always been happy to see the competition: “Infineon has been in the silicon carbide field for several years and has accumulated a lot of professional technical knowledge and capabilities. A long-term race, even an ultra-marathon. Infineon has this advantage, and at the same time, we are also happy to see competition, and competition can lead to progress.”

Author: Yoyokuo