Question

A charger supplies 100 W at 20 V for charging the battery of a laptop. The power devices, used in the converter inside the charger, operate at a switching frequency of 200 kHz. Which power device is best suited for this purpose?

• A. IGBT
• B. Thyristor
• C. MOSFET
• D. BJT

Hint:

MOSFETs are ideal for high-frequency applications due to their fast switching times and efficiency in handling low power.

Answer 1

The Correct Option is C

Step 1: Understand the application.
For a charger that operates at a high switching frequency (200 kHz), the power device must be capable of switching rapidly and efficiently. The device must also handle relatively low power (100 W) and have high-frequency switching capabilities. Step 2: Analyze the options.
- (A) IGBT: While IGBTs are efficient at switching at lower frequencies, they are not the best suited for high-frequency applications like this.
- (B) Thyristor: Thyristors are not suitable for high-frequency switching because they are typically used in low-frequency applications.
- (C) MOSFET: This is the correct answer. MOSFETs are ideal for high-frequency switching applications like the one described, especially in low-power applications.
- (D) BJT: BJTs are not as efficient as MOSFETs at high switching frequencies and are therefore less suitable for this application.
Step 3: Conclusion.
The correct answer is (C) MOSFET, as it is best suited for high-frequency switching in low-power applications like the laptop charger.