Bipolar transistors

Which model represents the large-signal behavior of a bipolar transistor with two diodes and current sources?

  1. AShockley's depletion approximation
  2. BThe Poisson model
  3. CThe Ebers-Moll model
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Answer: C. The Ebers-Moll model

The Ebers-Moll model represents the base-emitter and base-collector junctions as diodes, combined with current sources that pass a current depending on the current of the other junction. A single model covers the active, saturation and cutoff regions.

  • A. The depletion approximation is used to analyze the depletion layer of a PN junction, not to model a whole transistor.
  • B. The Poisson model is used for calculations such as yield.
  • C. Correct. It uses two diodes and dependent current sources.
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More Bipolar transistors questions

  1. How does the current gain hFE of a bipolar transistor depend on collector current?
  2. Which correctly relates BVCEO, the collector-emitter breakdown voltage with the base open, and BVCBO, the collector-base breakdown voltage with the emitter open?
  3. Which correctly describes the Miller effect that degrades the high-frequency performance of a common-emitter amplifier?
  4. What is the aim of a transistor with a Schottky barrier diode connected across its base-collector junction (a Schottky clamp)?
  5. Which bias condition is correct when an NPN transistor is used for amplification (operated in the active region)?