🚨 The Problem :

When switching inductive loads (like motors, relays, or transformers), MOSFETs face voltage spikes due to the sudden collapse of magnetic fields. These spikes can exceed the breakdown voltage of the MOSFET, leading to avalanche breakdown—a condition that may permanently damage your device.

🛠️ The Solution :

Use avalanche-rated MOSFETs or add flyback diodes (also known as freewheeling diodes) across inductive loads. These components safely redirect excess voltage away from the MOSFET, extending its life.

💡 Practical Example :

Imagine you’re building a smart fan controller using a MOSFET to switch a 12V DC motor. When you turn off the motor, its coil can generate a 100V+ spike! A simple 1N5819 Schottky diode across the motor terminals clamps the spike and protects your MOSFET.

🧮 Sample Calculation :

If your motor coil has 10mH inductance and the current is 1A:

Energy stored = ½ × L × I² = 0.5 × 0.01 × 1² = 0.005 Joules

Your diode must safely dissipate this energy repeatedly—choose one with adequate reverse recovery and power rating.

🛒 Product Suggestion :

🔗 MOSFET

🔗 Schottky Diode

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