Fundamentals of Electrical Practice: Identification and Measurement of Insulated-Gate Bipolar Transistors (IGBTs)

Fundamental Skills Training in Marine Electronics and Electrical Systems

I. Basic Concepts of Insulated-Gate Bipolar Transistors (IGBTs)

An insulated-gate bipolar transistor is a MOSFET 和Bipolar TransistorA composite device with an MOSFET as the input stage and a PNP transistor as the output stage. It combines the advantages of both devices:

It has both:The advantages of MOSFET devices—low drive power and fast switching speed.

It also has:The advantages of bipolar devices, which have low saturation voltage and high capacitance.

Its frequency characteristics fall between those of a MOSFET and a power transistor, and it can operate normally within a frequency range of several tens of kilohertz. IGBTs are finding increasingly widespread application in modern power electronics and have come to dominate high-frequency, medium- and high-power applications.

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Figure 12-8 Insulated-Gate Bipolar TransistorIGBTSymbols and Appearance

II. Measurement of Insulated-Gate Bipolar Transistors (IGBTs)

1. Pin Identification (G, C, E)

Step 1: Identify the gate (G)

Place the multimeter on R×1k Testing: If the resistance between a particular terminal and the other two terminals is infinite, and remains infinite even after swapping the test leads, then this terminal is determined to beGate (G)。

Step 2: Identify the collector (C) and the emitter (E)

Measure the other two terminals; if the resistance reads infinite, swap the test leads and measure the resistance again. In the measurement where the resistance is lower:

● The red probe is connected to: the collector (C)
● The black probe is connected to the emitter (E)

2. Determining Good or Bad (Human Motion Sensor Trigger Experiment)

Using a multimeter R×1k Testing the gear:

(1) Trigger On:
Connect the black probe to C and the red probe to E. Briefly touch both with your finger at the same time.Gate (G) 和Collector (C)At this point, the IGBT is triggered to turn on, and the pointer swings toward the lower resistance value.

(2) Shutdown blocking:
Touch both at the same time with your fingerGate (G) 和Emitter (E)At this point, the IGBT is turned off, and the pointer returns to zero.

If the above steps are completed successfully, you can conclude that the IGBT is in good working order.

3. Important Notes (Important)

Any analog multimeter can be used to test an IGBT.
Key:When determining whether something is good or bad, be sure to set it to R×1k Gear. This is because the battery voltage in gears below R×1k is too low to trigger IGBT gate turn-on.
This method is also suitable for detectingPower Field-Effect Transistor (P-MOSFET) its quality.