MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) have high input impedance, low noise, and good thermal stability. They feature a simple manufacturing process and strong radiation resistance, so they are usually used in amplifier circuits or switching circuits.

(1) Key selection parameters: Drain-source voltage VDS (voltage withstand), continuous drain current ID, on-resistance RDS(on), input capacitance Ciss (junction capacitance), figure of merit FOM = Ron * Qg, etc.

(2) Classification by different processes:

Trench MOS: Trench-type MOS, mainly used in low-voltage fields (within 100V);

SGT (Split Gate) MOS: Split-gate MOS, mainly used in medium and low-voltage fields (within 200V);SJ MOS: Superjunction MOS, mainly used in high-voltage fields (600-800V).

In switching power supplies, such as open-drain circuits, where the drain is directly connected to the load (known as an open-drain configuration), the load current can be turned on and off regardless of the voltage level of the load. This makes MOSFETs ideal analog switching devices, which is the principle of MOSFETs as switching devices (for details, please follow the author’s other MOS explanations).

In terms of market share, MOSFETs are almost dominated by international manufacturers. Infineon became the industry leader after acquiring IR (International Rectifier) in 2015. ON Semiconductor also jumped to the second place in market share after completing the acquisition of Fairchild Semiconductor in September 2016. The subsequent rankings are Renesas, Toshiba, International Rectifier, STMicroelectronics, Vishay, Nexperia, Magnachip, etc.

Compared with international manufacturers active in mainland China, domestic enterprises have no obvious advantages, but this does not mean there are no opportunities for domestic brands. Mainland China has the most complete industrial chain in the world, and there are a number of local manufacturing enterprises active in the power semiconductor field. At present, they have basically completed the industrial chain layout and are in a stage of rapid development. Especially in the MOSFET field, domestic brands have the greatest potential to replace imported brands in the medium and low-voltage fields. Some domestic enterprises, such as Silan, China Resources Microelectronics (AVIC), Jilin Sino-Microelectronics, and Lu Jing Electronics, are striving to enter the global rankings.