Download IGBT: Insulated-Gate Bipolar Transistor

IGBT: Insulated-Gate Bipolar Transistor
• Combination BJT and MOSFET
– High Input Impedance (MOSFET)
– Low On-state Conduction Losses (BJT)
• High Voltage and Current Ratings
• Symbol
ECE 442 Power Electronics
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Cross-Sectional View of an IGBT
Metal
Silicon Dioxide
Metal
ECE 442 Power Electronics
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IGBT Equivalent Circuit for VGE<VT
+
IBPNP
VCC
IEPNP
ICNPN
IBNPN
Leakage Current
ICPNP
Both transistors are OFF
IENPN
IRBE
ECE 442 Power Electronics
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IGBT Equivalent Circuit for VGE>VT
+
PNP transistor turns ON,
VCC
RMOD decreases due to
carrier injection from the
PNP Emitter.
MOS transistor conducts,
drawing current from the
Base of the PNP transistor.
ECE 442 Power Electronics
NPN Transistor
becomes forward
biased at the BE,
drawing current
from the Base of
the PNP transistor.
4
Channel is Induced When VGE>VT
RMOD
PNP
electrons
NPN
RBE
Induced Channel
ECE 442 Power Electronics
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IGBT Output Characteristics
Follows an SCR
characteristic
ECE 442 Power Electronics
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IGBT Transfer Characteristic
ECE 442 Power Electronics
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IGBT Used as a Switch
ECE 442 Power Electronics
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Fairchild FGA25N120AND IGBT
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