Inquire about mos tube function

At present, there are not many MOS tubes used on motherboards or graphics cards, generally around 10. The main reason is that most MOS tubes are integrated in IC chips. Because MOS tube mainly provides stable voltage for accessories, it is generally used near CPU, AGP slot and memory slot. Among them, a set of MOS tubes are arranged near the CPU and AGP slot, while the memory slot * * * uses a set of MOS tubes. Generally speaking, MOS transistors appear in groups of two on the motherboard. Working Principle Bipolar transistor amplifies the small current change at the input end and then outputs the large current change at the output end. The gain of bipolar transistor is defined as the ratio of output current to input current (β). Another transistor, called FET, converts the change of input voltage into the change of output current. They are current control devices and voltage control devices. The gain of FET is equal to its transconductance (gm), which is defined as the ratio of output current change to input voltage change. The name of FET also comes from its input gate (called gate), which affects the current flowing through the transistor by projecting an electric field on the insulating layer (oxide SIO2). In fact, no current flows through this insulator (only the function of capacitor), so the gate current of FET is very small (current loss of capacitor). The most common FET uses a thin layer of silicon dioxide as an insulator under the gate electrode. This kind of transistor is called a metal oxide semiconductor (MOS) transistor, or a metal oxide semiconductor field effect transistor (MOSFET).