Power semiconductors

Which correctly describes an IGBT?

  1. AA two-terminal device with only two PN junctions
  2. BA device driven by a MOS gate that achieves a low on-state voltage through conductivity modulation from bipolar operation
  3. CA thyristor turned on by light
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Answer: B. A device driven by a MOS gate that achieves a low on-state voltage through conductivity modulation from bipolar operation

An IGBT (insulated-gate bipolar transistor) combines the input section of a MOSFET with the output section of a bipolar transistor. It is voltage-driven, so the drive circuit is simple, and in the on state, minority carriers injected from the collector side lower the resistance of the drift layer (conductivity modulation), so the on-state voltage stays low even at high voltage ratings.

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More Power semiconductors questions

  1. Which is the channel through which current flows in a GaN HEMT?
  2. Which correctly describes the relationship between breakdown voltage and on-resistance in silicon power MOSFETs?
  3. What is the main role of an inverter in power electronics?
  4. In power devices, which loss mainly increases when the switching frequency is raised?
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