Consider the following statements regarding the Power MOSFET and IGBT:1.MOSFETs have a positive temperature coefficient of resistance, making them easy to parallel.2.IGBTs exhibit "current tailing" during turn-off, which increases switching losses.3.MOSFETs are preferred over IGBTs for low-power applications with switching frequencies above 200 kHz.4.Both devices are current-controlled semiconductor switches.Which of the statements given above are correct?

Correct Answer: A - 1, 2 and 3 only

Quick Concept Explanation

Power MOSFETs are majority-carrier, voltage-controlled devices with fast switching and a positive temperature coefficient of on-resistance that assists current sharing in parallel. IGBTs combine MOS-gate drive with bipolar conduction and exhibit tail current at turn-off, making them attractive at higher voltage/power but usually lower switching frequency than MOSFETs.

Exam focus: High-frequency low/medium voltage → MOSFET; higher voltage/power → often IGBT. Common trap: Both MOSFET and IGBT are not current-controlled devices.

Statement-wise Verification

• Statement 1 - Correct.
  MOSFETs have a positive temperature coefficient of resistance, making them easy to parallel.
  Power MOSFETs are majority-carrier, voltage-controlled devices with fast switching and a positive temperature coefficient of on-resistance that assists current sharing in parallel.
• Statement 2 - Correct.
  IGBTs exhibit "current tailing" during turn-off, which increases switching losses.
  IGBTs combine MOS-gate drive with bipolar conduction and exhibit tail current at turn-off, making them attractive at higher voltage/power but usually lower switching frequency than MOSFETs.
• Statement 3 - Correct.
  MOSFETs are preferred over IGBTs for low-power applications with switching frequencies above 200 kHz.
  IGBTs combine MOS-gate drive with bipolar conduction and exhibit tail current at turn-off, making them attractive at higher voltage/power but usually lower switching frequency than MOSFETs.
• Statement 4 - Incorrect.
  Both devices are current-controlled semiconductor switches.
  MOSFETs and IGBTs are gate-voltage/charge-controlled power devices

Core Concept

Power MOSFETs are majority-carrier, voltage-controlled devices with fast switching and a positive temperature coefficient of on-resistance that assists current sharing in parallel. IGBTs combine MOS-gate drive with bipolar conduction and exhibit tail current at turn-off, making them attractive at higher voltage/power but usually lower switching frequency than MOSFETs.

Formula / Key Relationship

Gate drive is voltage/charge controlled; MOSFET conduction loss≈I²R_DS(on).

Why the Other Options Are Wrong

Option B is incorrect because it includes incorrect statement(s) 4 and omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2. Option D is incorrect because it includes incorrect statement(s) 4.

Exam Shortcut / Approach

High-frequency low/medium voltage → MOSFET; higher voltage/power → often IGBT.

Common Mistake

Both MOSFET and IGBT are not current-controlled devices.

Quick Revision

Switching Characteristics and Paralleling is linked with MOSFET and IGBT, Power Semiconductor Devices and Power Electronics. High-frequency low/medium voltage → MOSFET; higher voltage/power → often IGBT.