IGBT - Insulated Gate Bipolar Transistor
1. IGBT is the short form of Insulated Gate Bipolar Transistor.
2. IGBT is a combination of BJT and MOSFET,
3. It has the input characteristics of a MOSFET and output characteristics of BJT.
4. The IGBT is a Voltage controlled device, hence it only requires a small voltage
to the gate to stay in the conduction state.
5. And since these are unidirectional devices, they can only switch current in the
forward direction which is from collector to emitter.
6. It is a three-terminal semiconductor switching device that can be used for fast
switching with high efficiency in many types of power electronic devices.
7. Applications include AC/DC drives, UPS, Inverters, High Freq Induction
heating devices, Switch Mode Power Supplies (SMPS), traction motor control
etc
8. Symbol of IGBT
9. The input side represents a MOSFET with a Gate terminal and the output side
represents a BJT with Collector and Emitter. The Collector and the Emitter are
the conduction terminals and the gate is the control terminal with which the
switching operation is controlled.
Internal Structure of IGBT
1. IGBT has three terminals attached to three different metal layers, the metal
layer of the gate terminal is insulated from the semiconductors by a layer of
silicon dioxide (SIO2).
2. IGBT is constructed with 4 layers of semiconductor sandwiched together. The
layer closer to the collector is the p+ substrate layer above that is the n- layer,
another p layer is kept closer to the emitter and inside the p layer, we have
the n+ layers.
3. The junction between the p+ layer and n- layer is called the junction J2 and the
junction between the n- layer and the p layer is called the junction J1.
4. The structure of IGBT is shown in the figure below.
1. IGBT is the short form of Insulated Gate Bipolar Transistor.
2. IGBT is a combination of BJT and MOSFET,
3. It has the input characteristics of a MOSFET and output characteristics of BJT.
4. The IGBT is a Voltage controlled device, hence it only requires a small voltage
to the gate to stay in the conduction state.
5. And since these are unidirectional devices, they can only switch current in the
forward direction which is from collector to emitter.
6. It is a three-terminal semiconductor switching device that can be used for fast
switching with high efficiency in many types of power electronic devices.
7. Applications include AC/DC drives, UPS, Inverters, High Freq Induction
heating devices, Switch Mode Power Supplies (SMPS), traction motor control
etc
8. Symbol of IGBT
9. The input side represents a MOSFET with a Gate terminal and the output side
represents a BJT with Collector and Emitter. The Collector and the Emitter are
the conduction terminals and the gate is the control terminal with which the
switching operation is controlled.
Internal Structure of IGBT
1. IGBT has three terminals attached to three different metal layers, the metal
layer of the gate terminal is insulated from the semiconductors by a layer of
silicon dioxide (SIO2).
2. IGBT is constructed with 4 layers of semiconductor sandwiched together. The
layer closer to the collector is the p+ substrate layer above that is the n- layer,
another p layer is kept closer to the emitter and inside the p layer, we have
the n+ layers.
3. The junction between the p+ layer and n- layer is called the junction J2 and the
junction between the n- layer and the p layer is called the junction J1.
4. The structure of IGBT is shown in the figure below.
