IV Characteristics of IGBT (Output Characteristics of IGBT)
Q. Draw symbols and V-I characteristics of following device : IGBT
Q. Draw symbol and characteristics of power semiconductor and its important information and application.
- The IV characteristics of IGBT is as shown in Figure.
- In the forward direction they are similar to those of the logic level bipolar transistor, the only difference here is that the controlling parameter is the gate to source voltage VGS and the parameter being controlled is the drain current.
- Thus IGBT is a voltage controlled device with an insulated gate. The drain current increases with increase in VGS at a constant value of VDS
- The IGBT possesses all the advantages of MOSFET due to the insulated gate. It also has all the advantages of the BJT due to bipolar conduction.
- As seen from the Figure the drain current (or the collector current) increases with increase in the voltage between gate and source (VGS).
- Also note that the gate to source voltage VGS is positive. B VDSS is the forward breakdown voltage.
- This is the value of VDS at which the avalanche breakdown takes place. At this point the voltage across the device and current through it both are high.
- Therefore the power dissipated in the device will be very large and will damage it. The device must be therefore operated below this voltage.