IGBT(Isolated Gate Bipolar Transistor)

itutorial - IGBT(Isolated Gate Bipolar Transistor) is a transistor device built by combining the capabilities of Bipolar Junction Transistor (BJT) and Metal Oxide Semiconductor Field Effect Transistors (MOSFET) The next transistor is ideal to use switch (switching device) to accommodate high voltage.

 

The main content of the IGBT mat can be used and utilized by the BJT and MOSFET components that will be used:

1. matter Crossroads (Collector-Emitter), while the MOSFET is between Drying And Source It is unipolar so it has the ability switch Learn more about BJTs.
2. MOSFET is a unipolar transistor so the majority of the current flows without passing through the PN Crossroads Anything but that conductivity modulation which causes the resistivity to change also does not occur. This is a disadvantage of MOSFETs, namely that it is difficult to reduce on resistance (RDS on) If a MOSFET is connected to a device, it will not be able to connect to that device. loss (current power loss in the state) is larger than BJT.
3. The BJT is responsible for controlling the devices in the terminal Base To control the flow of electric current at the terminal Collector-Emitter With the main requirement of voltage Base-Emitter Price of 0.7 Volt, sedan MOSFET, different prices Drain Source Controlled by the voltage at the terminals Gate.

To gain speed switch These MOSFETs can also be used today when MOSFETs and BJTs work together with other IGBT devices.

 

IGBT has characteristics output like BJT but output You can use this MOSFET to replace MOSFET. IGBT has impedance enter You will definitely feel happy about it switch This way the MOSFET is used, so the IGBT can use it to replace the BJT, so the MOSFET has the best MOSFET and the BJT is ideal to use. switch which is able to handle the current flowing at the terminal Collector-Emitter which is quite large (high voltage) with voltage trigger on the terminal Gate which is quite low. IGBT has 3 terminals viz Gate – Collector – Emitter. The IGBT symbol is shown in Figure 1.

Figure 1. Symbol Isolated Gate Bipolar Transistor (IGBT)

 

To explain how the IGBT works, look at the picture which shows the IGBT equivalent circuit which is illustrated by a combination of a MOSFET and a BJT.

Figure 2. Circuit equipped with IGBT

 

The simplest IGBT equivalent circuit consists of a PNP type BJT and a MOSFET N channel. This MOSFET also protects the patient from passion flowing through the terminal Gate. Current terminal Collector The pad is more connected to the terminal emitter connected on land.

 

To activate an IGBT is very simple, namely by applying voltage to the terminal Gate-Emitter Greater than voltage Gate-Emitter Threshold (VGET), and to turn off the IGBT, just use the 0 Volt voltage section or the terminal voltage section Gate-Emitter This book is full threshold IGBT. By including voltage Gate-Emitter This may occur with other terminal bearings Collector This may happen on the other side of the page VGE current will reach maximum. This may be your first time reading it.

 

Curve Characteristics Iinput

No need to install the bag on the terminal Collector-Emitter Increases as the voltage at the terminal increaseslGate. This method is used to translate IGBT.

Figure 3. Characteristics enter IGBT

 

The IGBT now supplies electrical current from the terminal Collector to emitter if the voltage at the terminal Gate-Emitter (VGE) is greater than the voltage Emitter-Threshold Gate (VGET) IGBT will be updated soon:

 

Curve Characteristics output

Figure 4 curve shows the relationship between stresses Gate-Emitter (VGE), voltage Collector-Emitter As well as the current flowing at the terminal Collector (IC).

Figure 4. Characteristics output IGBT

 

Characteristic Curve Figure 4 illustrates that:

1. Current voltage VGE It can also be connected to the pad terminal Collector going to emitter come up. This represents an increase in current at the terminal Collector Influenced by the amount of voltage at the terminal Gate-Emitter.
2. When on value VGE certain (VGE > VGET), the IGBT is in a saturation state where the current at the terminal Collector fixed or constant despite the voltage at the terminals Collector-Emitter raised.
3. It can also be downloaded from the terminal Collector-Emitter (VC.E) is increased continuously up to a certain value (voltage value braking VBC) then IGBT will experience details Where is the current at the terminal collector increases to maximum quickly. At this point the IGBT may become damaged. Maximum limit value or voltage value details IGBT can be seen at data sheet IGBT used.

The amount of current flowing at the terminal emitter The same as the current flowing at the terminal Collector, This is because theoretically there is no current flowing at the terminal Gate going to emitter.

 

Important general variables are found in data sheet IGBT

Several variables that need to be considered when designing a circuit switch IGBT is used so that the IGBT device used is not damaged. Some common variables are listed below data sheet IGBT is as follows:

 

VCES : Maximum voltage Collector-Emitter so that the IGBT does not enter the condition avalanche damage which can cause damage, the voltage applied to the terminals Collector-Emitter Must be under rated VCES.

 

VGES : Maximum terminal voltage Gate-Emitter. Voltage Gate-Emitter Limited by the nature and thickness of the oxide material Gate. This application will be completed later VGE Read more about it VGES So that the IGBT does not experience damage to the oxide layer.

 

VGE(th) – Gate-Emitter Qthreshold voltage : Is the minimum voltage at the terminal Gate-Emitter so that the IGBT Enters the state in the state Or work.

 

QJ : Operating temperature range Crossroads Time has passed since the end of the IGBT period, so IGBT people can take advantage of it to do so.

 

Rth(jc) : Thermal resistance junction to the casing.

Is thermal resistance which describes the stable resistance at a certain temperature caused by dc electrical conditions.

 

IC : The dc current that is allowed to flow at the terminal Collector. Current Collector Maximum is defined as the amount of current flowing continuously at a certain temperature which is commonly referred to as QC. To reach temperature Crossroads maximum allowable (QJ), then the maximum current Collector permitted can be stated as follows:

Where:

• Rth(jc) Resistance hot IGBT.
• INCEsat: Voltage during compression in the state Collector-Emitter with current ICwhich has been specified.

There are many people Collector The maximum above can be concluded that the maximum current magnitude at Collector No need to worry about this and anything else.

 

ICES (Collector-Emitter Breaker Current) : Is a current Collector IGBT says it's the same as IGBT out of state (leakage current) under conditions front blocking mode. ICES Determine the magnitude of the leakage current value at voltage Gate-Emitter 0 volts.

IF (Diode Forward Current) :

IF Again proceed The maximum that can flow at a given fixed temperature QC but still below temperature QJ maximum. Mark IF This will be done later:

 

 

PD (power dissipation)

 

Power dissipation generally determined by the equation:

 

Forward transconductance (gfs) : Is a comparison of the value of the current change at the terminal Collector to changes in voltage values ​​at the terminals Gate-Emitter. Mark Gfs There is a lot of data that is not covered by the Internet and the number of people using IGBTs connected to the Internet. Transconductance Gfs Has a Siemens or Mhos unit

Figure 5. Illustration of IGBT transconductance measurements (Gfs)

 

 

 

Qstg : The maximum allowable temperature at which the IGBT can be stored without current or voltage.

 

And there are many other important variables data sheet IGBT as a reference for making control circuits using IGBT.

 

There are many people who have access to a large number of people who have access to the IGBT system to connect them to each other at the same time with pad terminals. Collector-Emitter It is influenced by the temperature of the IGBT so it is very important to determine the maximum temperature of the operational circuit that you will make.

 

IGBT applications are generally used for various needs switch This may be day by day:

• Motor control.
• UPS(Seamless power source ).
• Solar inverter.
• Induction heaters are like induction cookers.