Bipolar transistors

Which correctly relates BVCEO, the collector-emitter breakdown voltage with the base open, and BVCBO, the collector-base breakdown voltage with the emitter open?

  1. ABVCEO and BVCBO are always equal
  2. BBVCEO is lower than BVCBO
  3. CBVCEO is higher than BVCBO
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Answer: B. BVCEO is lower than BVCBO

With the base open, avalanche current generated at the collector junction flows into the base and is amplified by transistor action. As a result, the current surges and breakdown occurs at a voltage lower than BVCBO. Circuit designs must use the lower BVCEO as the guideline.

  • A. The two breakdown voltages generally differ.
  • B. Correct. Because of the gain, BVCEO is lower than BVCBO.
  • C. Transistor action makes BVCEO the lower of the two.
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More Bipolar transistors questions

  1. Which correctly describes the Miller effect that degrades the high-frequency performance of a common-emitter amplifier?
  2. What is the aim of a transistor with a Schottky barrier diode connected across its base-collector junction (a Schottky clamp)?
  3. Which bias condition is correct when an NPN transistor is used for amplification (operated in the active region)?
  4. Which expression gives the DC current gain hFE of a bipolar transistor? (IC: collector current, IB: base current, IE: emitter current)
  5. What is the main reason for making the base of a bipolar transistor thin?