The principle, characteristics and parameters of insulated gate bipolar transistor

The principle, characteristics and parameters of insulated gate bipolar transistor

Insulated gate bipolar transistor IGBT is also called insulated gate bipolar transistor.

one. How Insulated Gate Bipolar Transistor Works:
The semiconductor structure analysis is omitted. Relevant materials are attached to this handout for interested colleagues to consult.
The device symbol is as follows:

AG3P57{AM2GI5Z42A%O$0DU.png

N-channel P-channel
Figure 1-8: Graphical Symbols of IGBTs

Note that its three electrodes are gate G, collector C, and emitter E.

Figure 1-9: Equivalent circuit diagram of an IGBT.

The equivalent circuit diagram of the device is given above. In fact, it is equivalent to combining MOS tube and Darlington transistor. Therefore, it has the advantages of MOS tube and GTR at the same time.

two. Features of Insulated Gate Bipolar Transistors:
This device features a combination of the advantages of a MOSFET and a GTR. High input impedance, fast speed and good thermal stability. The on-state voltage is low, the withstand voltage is high, and the current is large.
Its current density is larger than that of MOSFET, and the chip area is only 40% of that of MOSFET. But the speed is slightly lower than MOSFET.
High-power IGBT modules reach the level of 1200-1800A/1800-3300V (reference). The speed is in the medium voltage region (370-600V) and can reach 150-180KHz.

three. Parameters and characteristics of insulated gate bipolar transistors:
(1) Transfer characteristics

图1-10:IGBT的转移特性

        这个特性和MOSFET极其类似,反映了管子的控制能力。
  (2)输出特性

图1-11:IGBT的输出特性

        它的三个区分别为:
        靠近横轴:正向阻断区,管子处于截止状态。
        爬坡区:饱和区,随着负载电流Ic变化,UCE基本不变,即所谓饱和状态。
        水平段:有源区。
  (3)通态电压Von:

Figure 1-12: Comparison of IGBT on-state voltage and MOSFET

The so-called on-state voltage refers to the tube voltage drop VDS when the IGBT enters the on-state, and this voltage decreases with the increase of VGS.
As can be seen from the above figure, when the on-state voltage of IGBT is relatively large, Von is smaller than that of MOSFET.
Von of MOSFET is positive temperature coefficient, IGBT small current is negative temperature coefficient, and large current range is positive temperature coefficient.
(4) Switching loss:
At room temperature, the turn-off losses of IGBTs and MOSFETs are similar. MOSFET switching losses have little to do with temperature, but for every 100°C increase in IGBT, the losses increase by a factor of two.
Turn-on losses in IGBTs are on average slightly smaller than in MOSFETs, and both are temperature-sensitive and exhibit a positive temperature coefficient.
The switching losses of the two devices are related to the current, and the higher the current, the higher the loss.
(5) Safe working area and main parameters ICM, UCEM, PCM:
The safe operating area of ​​IGBT is the area surrounded by current ICM, voltage UCEM, and power dissipation PCM.

Figure 1-13: Power dissipation characteristics of IGBTs

The maximum collector-emitter voltage UCEM: depends on the reverse breakdown voltage.
Maximum Collector Power Dissipation PCM: Depends on allowable junction temperature.
The maximum collector current ICM: is limited by the component hold-up effect.
The so-called holding effect problem: because the IGBT has a parasitic transistor, when the IC is large to a certain extent, the parasitic transistor is turned on, and the gate loses control. At this time, the leakage current increases, resulting in a sharp increase in power consumption and device damage.
The safe operating area decreases as the switching speed increases.
(6) Gate bias voltage and resistance
IGBT characteristics are mainly controlled by gate bias and are also affected by surge voltage. Its di/dt is obviously related to the gate bias voltage and resistance Rg. The higher the voltage, the larger the di/dt, the larger the resistance, and the smaller the di/dt.
Moreover, the relationship between the gate voltage and the short-circuit damage time is also very large. The higher the gate bias voltage, the shorter the short-circuit damage time.

The principle, characteristics and parameters of insulated gate bipolar transistor

Insulated gate bipolar transistor IGBT is also called insulated gate bipolar transistor.

one. How Insulated Gate Bipolar Transistor Works:
The semiconductor structure analysis is omitted. Relevant materials are attached to this handout for interested colleagues to consult.
The device symbol is as follows:

N-channel P-channel
Figure 1-8: Graphical Symbols of IGBTs

Note that its three electrodes are gate G, collector C, and emitter E.

Figure 1-9: Equivalent circuit diagram of an IGBT.

The equivalent circuit diagram of the device is given above. In fact, it is equivalent to combining MOS tube and Darlington transistor. Therefore, it has the advantages of MOS tube and GTR at the same time.

two. Features of Insulated Gate Bipolar Transistors:
This device features a combination of the advantages of a MOSFET and a GTR. High input impedance, fast speed and good thermal stability. The on-state voltage is low, the withstand voltage is high, and the current is large.
Its current density is larger than that of MOSFET, and the chip area is only 40% of that of MOSFET. But the speed is slightly lower than MOSFET.
High-power IGBT modules reach the level of 1200-1800A/1800-3300V (reference). The speed is in the medium voltage region (370-600V) and can reach 150-180KHz.

three. Parameters and characteristics of insulated gate bipolar transistors:
(1) Transfer characteristics

图1-10:IGBT的转移特性

        这个特性和MOSFET极其类似,反映了管子的控制能力。
  (2)输出特性

图1-11:IGBT的输出特性

        它的三个区分别为:
        靠近横轴:正向阻断区,管子处于截止状态。
        爬坡区:饱和区,随着负载电流Ic变化,UCE基本不变,即所谓饱和状态。
        水平段:有源区。
  (3)通态电压Von:

Figure 1-12: Comparison of IGBT on-state voltage and MOSFET

The so-called on-state voltage refers to the tube voltage drop VDS when the IGBT enters the on-state, and this voltage decreases with the increase of VGS.
As can be seen from the above figure, when the on-state voltage of IGBT is relatively large, Von is smaller than that of MOSFET.
Von of MOSFET is positive temperature coefficient, IGBT small current is negative temperature coefficient, and large current range is positive temperature coefficient.
(4) Switching loss:
At room temperature, the turn-off losses of IGBTs and MOSFETs are similar. MOSFET switching losses have little to do with temperature, but for every 100°C increase in IGBT, the losses increase by a factor of two.
Turn-on losses in IGBTs are on average slightly smaller than in MOSFETs, and both are temperature-sensitive and exhibit a positive temperature coefficient.
The switching losses of the two devices are related to the current, and the higher the current, the higher the loss.
(5) Safe working area and main parameters ICM, UCEM, PCM:
The safe operating area of ​​IGBT is the area surrounded by current ICM, voltage UCEM, and power dissipation PCM.

Figure 1-13: Power dissipation characteristics of IGBTs

The maximum collector-emitter voltage UCEM: depends on the reverse breakdown voltage.
Maximum Collector Power Dissipation PCM: Depends on allowable junction temperature.
The maximum collector current ICM: is limited by the component hold-up effect.
The so-called holding effect problem: because the IGBT has a parasitic transistor, when the IC is large to a certain extent, the parasitic transistor is turned on, and the gate loses control. At this time, the leakage current increases, resulting in a sharp increase in power consumption and device damage.
The safe operating area decreases as the switching speed increases.
(6) Gate bias voltage and resistance
IGBT characteristics are mainly controlled by gate bias and are also affected by surge voltage. Its di/dt is obviously related to the gate bias voltage and resistance Rg. The higher the voltage, the larger the di/dt, the larger the resistance, and the smaller the di/dt.
Moreover, the relationship between the gate voltage and the short-circuit damage time is also very large. The higher the gate bias voltage, the shorter the short-circuit damage time.

The Links:   BSM50GB60DLC CM300DY-12HE