BYJ32056_FDS6984AS-NL Introduction

The resistance of this current path is called the internal resistance of the MOS tube, that is, the on-resistance. The size of this internal resistance basically determines how much on-current the MOS tube chip can withstand (of course, it is related to other factors, such as thermal resistance). The smaller the internal resistance, the larger the current (because the heat is small).

In simple terms, the motor is driven by the output current of the MOS tube such as NCE80H12. The larger the output current (in order to prevent overcurrent from burning the MOS tube, the controller has limited current protection), the motor torque is strong and the acceleration is powerful, so MOS Tubes play a very important role in electric vehicle controllers.

BYJ32056_FDS6984AS-NL

UPA1852GR-9JG-A

Power MOSFETs are generally rarely used in P-channel. Since the mobility of holes is lower than that of electrons, the on-resistance of P-channel transistors is larger than that of N-channel transistors for the same channel size. . According to the two points of the conductive channel and the process of channel formation, MOS tubes can be divided into: P-channel enhancement MOS tubes, P-channel depletion MOS tubes, N-channel enhancement MOS tubes and N-channel depletion MOS tubes . Figure four types of MOSFETs and their graphical symbols.

. The conductive channel of the MOS tube can be formed during the production process or by turning on an external power supply. When the gate voltage is equal to zero, there is a channel (that is, formed during production), which is called depletion mode. When an external voltage is applied The one that forms the channel later is called the enhancement type.

The reason is that the on-resistance is small and it is easy to manufacture. Therefore, in the application of switching power supply and motor drive, NMOS is generally used.

BYC4322 BYM4310 BYM4322 BYM4316 BYC4312 BYM438 BYS441 BYN4458 BYE4625Z BYM4612 .

BYJ32056_FDS6984AS-NL

D3N04H

The N-channel enhancement mode MOS transistor uses a low-doped P-type semiconductor as the substrate, and forms two heavily doped N+ regions on the substrate by a dispersed method, and then generates a very thin one on the P-type semiconductor. A silicon dioxide insulating layer, and then photolithography is used to etch away the silicon dioxide layer on the upper end of the two heavily doped N+ regions, exposing the N+ regions, and finally on the outer surface of the two N+ regions and the two between them. The surface of silicon oxide is sprayed with a layer of metal film by evaporation or sputtering. These three metal films constitute the three electrodes of the MOS tube, which are called source (S), gate (G) and drain (D) respectively. .

When the UDS increases to a certain value, the drain PN junction breaks down, the leakage current increases rapidly, and the curve turns upward and enters the breakdown region. Power MOSFETs are used in power conversions such as switching power supplies and inverters, and they work in two regions, the cut-off region and the breakdown region. . The full area (UDS>UGS-UT) guarded in the above three areas is the full area, also known as the constant current area or the amplification area. The breakdown region is in the region of considerable drain-source voltage UDS, and the drain current is approximately constant.

. The characteristics of a MOSFET can be characterized by a transfer characteristic curve and a drain output characteristic curve. Figure 3 shows the handling characteristics of a certain FET. The transfer characteristic refers to the relationship curve between the gate voltage UGS and the corresponding drain current ID when the voltage UDS between the drain and the source is at a certain fixed value.

For example, electronic fuel injection system, anti-lock brake control, anti-skid control, traction control, electronically controlled suspension, electronically controlled automatic transmission, electronic power steering, etc. The electronic device that can be used independently in the environment has no direct relationship with the performance of the car itself. .

BYJ32056_FDS6984AS-NL

NCE20ND06 NCE2008N NCE2312 NCE2312A NCE8205A.

NCE25TD135LT NCE15TD135LT NCE15TD120LP NCE15TD135LP NCE25TD120LP.

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