1 Answer
Yes, a Bipolar Junction Transistor (BJT) is controlled by current. In a BJT, the current flowing into the base controls the current flowing between the collector and emitter.
Here's how it works:
- **Base current (IB)**: A small current flowing into the base of the transistor controls the larger current that flows from the collector to the emitter.
- **Collector current (IC)**: The current that flows from the collector to the emitter is much larger and is proportional to the base current (IB). This relationship is typically described by the current gain (β) of the transistor, which is the ratio of the collector current to the base current (IC = β × IB).
So, while the voltage across the base-emitter junction (VBE) needs to be above a certain threshold (typically around 0.7V for silicon BJTs), it's the current flowing into the base that controls the larger current between the collector and emitter.
In short, **BJTs are current-controlled devices** because the base current controls the larger collector-emitter current.
Here's how it works:
- **Base current (IB)**: A small current flowing into the base of the transistor controls the larger current that flows from the collector to the emitter.
- **Collector current (IC)**: The current that flows from the collector to the emitter is much larger and is proportional to the base current (IB). This relationship is typically described by the current gain (β) of the transistor, which is the ratio of the collector current to the base current (IC = β × IB).
So, while the voltage across the base-emitter junction (VBE) needs to be above a certain threshold (typically around 0.7V for silicon BJTs), it's the current flowing into the base that controls the larger current between the collector and emitter.
In short, **BJTs are current-controlled devices** because the base current controls the larger collector-emitter current.