Which statement describes a BJT?

Which statement describes a BJT?

• A. High Input Impedance
• B. Fast Switching
• C. Low Power Consumption
• D. High Current/Voltage Handling

Answer: (D)

A BJT is a current-driven device in which a small base current controls a much larger current between collector and emitter. That current gain lets the transistor handle substantial collector currents, and, in power versions, sizable voltages as well, making it a common choice for amplification and power switching. The base-emitter junction behaves like a forward-biased diode, so the input impedance seen looking into the base is relatively low, not high. While BJTs can switch quickly, they don’t inherently match the very high-speed, low-resistance switching advantages of MOSFETs. They also don’t guarantee low power consumption, since power dissipation depends on the operating conditions (Vce times Ic and the drive needed to keep the device conducting). Taken together, the ability to handle high current and voltage is the characteristic that best describes a BJT.

A BJT is a current-driven device in which a small base current controls a much larger current between collector and emitter. That current gain lets the transistor handle substantial collector currents, and, in power versions, sizable voltages as well, making it a common choice for amplification and power switching. The base-emitter junction behaves like a forward-biased diode, so the input impedance seen looking into the base is relatively low, not high. While BJTs can switch quickly, they don’t inherently match the very high-speed, low-resistance switching advantages of MOSFETs. They also don’t guarantee low power consumption, since power dissipation depends on the operating conditions (Vce times Ic and the drive needed to keep the device conducting). Taken together, the ability to handle high current and voltage is the characteristic that best describes a BJT.