SMPS Input Noise Reduction Guide
🛠️ The Problem :
Switched-mode power supplies (SMPS) are incredibly efficient but often introduce high-frequency noise on the input side. This noise can interfere with nearby sensors, microcontrollers, or wireless modules, leading to unstable performance in your projects.
✅ The Solution :
To fix this, add input filtering components such as ferrite beads, X/Y capacitors, and common-mode chokes. These components help block or absorb the high-frequency noise, ensuring your SMPS runs cleanly and quietly.
🔍 Practical Example :
Say you’re powering a Wi-Fi-enabled IoT device using a 12V SMPS. Without input filtering, the power supply’s switching noise can interfere with your Wi-Fi module’s signal strength or ADC readings. Adding a ferrite bead (100Ω@100MHz) and 0.1µF ceramic capacitor across input lines significantly reduces the noise.
📐 Sample Calculation :
A pi-filter can be designed using:
C1 = 0.1µF (ceramic)
L = 100µH inductor
C2 = 100µF (electrolytic)
This suppresses frequencies above a few hundred kHz, cleaning up your input line.
🛒 Product Suggestion :
Look for ferrite beads or ceramic capacitors made in India:
Shop now at SmartXProKits.in
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