Understanding Thermal Runaway
The process described, where an increase in collector junction temperature leads to an increase in collector current, which in turn further increases the temperature, is known as thermal runaway.
This is a positive feedback mechanism:
- Higher Temperature → Higher Collector Current ($I_C$)
- Higher $I_C$ → Increased Power Dissipation ($P_D \approx V_{CE} \times I_C$)
- Increased $P_D$ → Higher Junction Temperature
This cycle escalates, potentially damaging the semiconductor device. The phrase "and vice versa" emphasizes this self-reinforcing loop.
Evaluating Other Options
- Temperature Stability: This refers to maintaining a stable operating point despite temperature variations, the opposite of runaway.
- Positive Feedback: While thermal runaway utilizes positive feedback, the term itself is more general. The question describes a specific consequence of positive feedback in this context.
- Oscillation: This involves periodic fluctuations, not a continuous escalating increase in current and temperature.
Important Questions from Bipolar Junction Transistors
Additional heat is dissipated from power transistor by using
When emitter-base junction of a transistor is reverse-biased, the collector current
Emitter follower is used for:
In the common-base configuration, the collector current is given by:
The circuit which produces the best stabilisation of an operating point is _______.
