⚡ The Problem: MOSFETs & Over-Voltage Damage

MOSFETs are great for high-speed switching, but they’re vulnerable to voltage spikes, especially across the drain-source or gate terminals. These surges—caused by inductive loads or switching transients—can permanently damage the MOSFET, leading to circuit failure.

🛠️ The Solution: Use an Over-Voltage Clamp

To protect MOSFETs, use TVS (Transient Voltage Suppressor) diodes or a zener clamp. These components absorb dangerous spikes and limit the voltage within safe operating levels. Adding a gate resistor also dampens voltage ringing and noise.

🧰 Practical Example: Motor Driver Protection

Say you’re controlling a 12V DC motor using an N-channel MOSFET. When the motor turns off, the collapsing magnetic field causes a spike. Without protection, your MOSFET’s drain may see 30V or more—destroying it.

Adding a 15V TVS diode across the drain-source clamps the voltage safely. Your MOSFET survives, and your project runs smoothly.

📏 Sample Calculation: Zener Clamp Setup

If your MOSFET is rated at 20V max Vds:

• Choose a TVS diode with breakdown at ~15V

• Ensure the peak pulse power rating > expected transient energy (e.g., 600W)

This ensures it absorbs spikes without failing.

🔌 Product Suggestions: Made in India Components

• 🛡️ TVS Diode Kit

• 📦 N-channel MOSFETs

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