Question

Which semiconductor power device out of the following is not a current triggered device?

• A. Thyristor
• B. GTO
• C. TRAIC
• D. MOSFET

Hint:

MOSFETs are voltage-controlled, making them faster and suitable for high-frequency applications, unlike current-triggered thyristors.

Answer 1

The Correct Option is D

Step 1: Understand triggering mechanism
Semiconductor devices can be classified based on how they are triggered (turned ON):
- Current-triggered devices: These require a gate current to initiate conduction. Examples include Thyristor, GTO (Gate Turn-Off thyristor), and TRIAC.
- Voltage-triggered devices: These are controlled by gate voltage rather than current. The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is a prime example.
Step 2: Analyze each option
- (1) Thyristor: A current-triggered device. Requires a gate pulse to turn ON.
- (2) GTO: Also a current-triggered device but has the added ability to turn OFF via gate current.
- (3) TRIAC: Bidirectional device, current-triggered, widely used for AC power control.
- (4) MOSFET: Voltage-controlled device. The gate draws almost no current; it's the voltage that controls conduction.
Conclusion:
MOSFET is not a current-triggered device — Option (4) is correct.