What is the high-power VMOS field effect transistor and how to detect it?

Last Update Time: 2018-12-25 11:24:29

What is the high-power VMOS field effect transistor and how to detect it?

This article writes about the high-power VMOS field effect transistor

l  Definition

VMOS field-effect transistor is a power field effect transistor, commonly referred to as VMOS tube, the whole name is V slot MOS field-effect transistor. There are 3 electrodes, namely, gate G, drain D and source S. The circuit symbols have two kinds of painting methods, one is the internal protection diode type, the other is the internal non protected diode type.

 

The VMOS tube is characterized by V groove and vertical conductivity. The leakage D is derived from the back of the chip, so the drain current Ip is not flowing along the surface, but from the heavy doped N+ region (source S), through the formation of a channel flow with the surface to the light doped N- drift region, and then to the drain D vertically. Therefore, it is often referred to as V MOSFET (vertical conductive metal oxide), which has V groove structure and vertical conductivity type semiconductor device. It has the characteristics of high input impedance, small drive flow, high voltage resistance, large working flow, large output power, good transconductance linearity and fast switching speed. The main parameters of high power VIMOS field effect transistor are as follows.

 

(1) The maximum leakage current IDM.

The drain current IDM represents the current capacity of the power MOSFET, the measurement condition is UGs=10V, and the drain current of UDs is a suitable value.

 

(2) The breakdown voltage of the leakage source was UDsM.

The leakage source breakdown voltage UDsM indicates that the voltage limit quantitative analysis of the power MOSFET is defined as UGs=0, when the reverse leakage current between the leakage sources reaches a specified value, the leakage source voltage.

 

(3) Transconductance GM.

Gm= AIp/AUcs, which reflects the slope of transfer characteristics, represents the amplification performance of power MOSFET.

 

(4) The capacitance between the poles.

The interpolar capacitance of the power MOSFET is the main factor affecting the switching speed. They are the capacitance CGs of the gate source, the capacitance CGD between the gate leaks and the capacitance of the drain source CDs.

 

(5) The threshold voltage Ucs (TB).

Threshold voltage Ucs (TB) refers to the minimum gate voltage of power MOSFET flowing through a certain amount of drain current. When the gate voltage is equal to the threshold voltage UGs (TB), the MOSFET starts to turn on.

The breakdown voltage of the gate source is UGs. The gate source breakdown voltage UGs represents the highest voltage that can withstand the power MOSFET gate source, and its value is generally 20V.

 

(6) Switch time. It includes the pass time ton and the turn off time oft. The conduction time to also includes the conduction delay time TD and the rise time tr. Turn off time TOF also includes turn off delay time TD and descent time t.

 

(7) The pass state resistance RoN. On state resistance refers to the DC resistance of MOSFET when it is in constant current area at a fixed gate voltage UGs, which determines the conduction loss of MOSFET.

 

l  High power MOSFET field-effect transistors detection.

Poles of power MOSFET: G and S and D are insulated each other.

There are two back-to-back diodes between D and S, so the pointer type multimeter (RX1Ω block) is very easy to judge its good or bad. In addition, a diode is paralleled between the drain and the source of power MOSFET, and the cathode and anode of the diode can be measured during testing.

This article is from Allicdata Electronics Limited.