2N7002A_NCEP048N72 Introduction

The power mos used on electric vehicles is a three-dimensional structure. Low-power mos is a planar structure. The mos tube we have seen is actually composed of thousands of small mos tubes in parallel. You may think that one or a few bad moss should easily appear in thousands of small mos. In fact, it is not that easy. , the current manufacturing process basically guarantees the high consistency of various parameters of these small units.

The smaller the internal resistance, the larger the current (because the heat is small). 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).

2N7002A_NCEP048N72

NCE30H32WD

NCE30H11K NCE3402B NCE30H10AK NCE2304 NCE3404.

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.

MOS tube 3306 product features 1. RDS(on)=7mΩ@VGS=10V 2. Lead-free green equipment 3. Low resistance switch to reduce conduction loss 4. High avalanche current.

. For these two enhanced MOS tubes, NMOS is more commonly used. As for why not to use depletion-type MOS tubes, it is not recommended to get to the bottom of it.

2N7002A_NCEP048N72

NCEP3085EG

When the applied forward voltage increases, the concentration of unbalanced minority carriers increases and the concentration gradient also increases, and when the applied voltage decreases, the change is opposite. Diffusion capacitance: When a forward voltage is applied, the non-equilibrium minority carrier concentration near the interface of the depletion layer is high, far from the non-equilibrium minority carrier concentration is low, and the concentration gradually decays from high to 0 until it reaches zero. The process of charge accumulation and release in this phenomenon is the same as that of capacitor charging and discharging, which is called diffusion capacitance.

. The parasitic capacitance structure of the MOS tube is as follows. Among them, the width of polysilicon, the width of the channel and the trench, the thickness of the G oxide layer, and the doping profile of the PN junction are all factors that affect the parasitic capacitance.

Variable resistance area (UDS In this area, when UDS increases, ID increases linearly. When the low UDS splitting and pinch-off voltage is large, the MOS tube is equivalent to a resistance, and this resistance decreases with the increase of UGS. Cut-off area (UGS). When the conductive channel is close to the pinch off, the growth slows down. Figure MOS tube drain output characteristics The output characteristics of field effect transistors can be divided into four regions: variable resistance region, cut-off region, breakdown region and constant current zone.

On the one hand, the three electrodes of the low-power MOSFET are on one plane, the channel cannot be made very short, and the channel resistance is large. On the other hand, the conductive channel is composed of surface induced charges, and the channel current is the surface current. To increase the current capacity, it is necessary to increase the chip area. Such a structure is unlikely to achieve a large current. . The structure of the MOSFET shown in the figure is not suitable for use in high-power applications for two reasons.

2N7002A_NCEP048N72

The functions of the MOS tube in the protection board are: 1. Detect overcharge, 2. Detect over-discharge, 3. Detect over-current during charging, 4. Detect over-current during discharge, 5. Detect over-current during short circuit.

NCE30TD120UT NCE40TD120UT NCE40TD120VT NCE30TD120BP NCE25TD120BT.

relevant information