25.3.2. Thermal Runaway Problem

Try these first

1. 1.

   What happens to beta when the temperature increases?

   Hint

   Think about the relationship between temperature and transistor performance.

2. 2.

   Define thermal runaway in the context of transistor circuits.

   Hint

   Consider how changes in temperature affect performance.

3. 3.

   What initiates the thermal runaway phenomenon in CE amplifiers?

   • Increased input signal
   • Higher temperature leading to increased beta
   • Reduced supply voltage

   Hint

   Think about the relationship between temperature and transistor behavior.

4. 4.

   True or False: Emitter resistors can negatively affect the gain of an amplifier.

   • True
   • False

   Hint

   Consider the trade-off between stability and performance.

5. 5.

   Design a common emitter amplifier that incorporates emitter degeneration. Discuss how you would balance the need for gain against the need for stability.

   Hint

   Focus on the formula for gain in relation to resistor values.

6. 6.

   Critically assess the impact of beta variability with temperature in different scenarios (e.g., high vs low-temperature environments) on a CE amplifier's performance.

   Hint

   Consider the extreme temperature ranges and how they could affect commercial applications of the amplifier.