⚠️ The Problem: High-Frequency Switching Noise

MOSFETs are great for switching applications, but they can generate high-frequency noise during rapid switching. This can lead to interference in audio circuits, power losses, or erratic behavior in nearby components.

🛠️ The Solution: Gate Resistors & Snubber Circuits

To reduce this noise, add a gate resistor (10–100Ω) to slow down the switching edge slightly, and use a snubber circuit (RC across drain and source) to suppress voltage spikes. These small tweaks reduce EMI without sacrificing much speed.

💡 Practical Example: Noisy Fan Controller

A maker in Bengaluru built a MOSFET-based fan speed controller. But at high PWM frequencies, the fan created a buzzing sound and nearby sensors glitched. Adding a 22Ω gate resistor and a 100nF + 10Ω snubber resolved the issue completely.

🧮 Sample Calculation: Gate Resistor Sizing

For a gate charge (Qg) of 30nC and desired switching time (t) of 100ns:

R = t / (Qg / Vgs) = 100ns / (30nC / 10V) = 33Ω

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