📡 The Problem: SMPS High-Frequency Noise

Switched Mode Power Supplies (SMPS) are efficient, but they produce high-frequency noise that can interfere with sensitive circuits—especially audio devices, sensors, and RF modules. This noise often appears as hum, buzz, or random data glitches.

🛠️ The Solution: Filtering & Layout Fixes

To reduce SMPS noise, use a combination of:

• Ferrite beads to block high-frequency spikes

• Electrolytic + ceramic capacitors for wide-band filtering

• Proper grounding and PCB layout to reduce coupling

Adding an LC or Pi filter at the SMPS output can also make a big difference.

🧪 Practical Example: Clean Power for Audio Circuits

Let’s say you power a Bluetooth speaker board using a 12V SMPS. You hear buzzing in the audio output—classic SMPS noise.

Solution:
Add a 10µH inductor in series and a 100µF electrolytic + 0.1µF ceramic capacitor in parallel to ground. This filters out high-frequency noise and delivers clean DC power.

🔢 Sample Calculation: LC Filter Cutoff Frequency

To block frequencies above 100kHz:

Use L = 10µH, C = 0.1µF

f_c = 1 / (2π√LC) ≈ 159kHz—perfect for SMPS noise filtering!

🧰 Product Suggestion: Made in India Components

Power clean with ferrite beads and ceramic capacitors from our Make in India collection.

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