Switch Mode Power Supplies (SMPS) are compact, efficient, and widely used—but they can become unstable if not properly handled. Unstable output voltage leads to glitches, restarts, or even damage to sensitive circuits like microcontrollers or sensors.

⚠️ The Problem: Ripple, Noise & Voltage Fluctuations

If your SMPS output isn’t stable, it may show symptoms like flickering displays, random resets in Arduino or Raspberry Pi boards, or poor sensor readings. This usually happens due to poor filtering, improper load, or lack of decoupling capacitors.

✅ The Solution: Proper Filtering & Decoupling

To stabilize SMPS output:

• Add low ESR capacitors (e.g., 100µF electrolytic + 0.1µF ceramic) near the load.

• Use ferrite beads or inductors to filter high-frequency noise.

• Ensure the SMPS operates within its rated load range—too light or too heavy a load can cause instability.

🔧 Practical Example

If you’re powering an ESP8266 Wi-Fi module with a 5V SMPS and see random reboots, you’re likely facing voltage dips. Adding a 100µF capacitor at the ESP’s VCC helps stabilize voltage during current spikes, solving the issue.

📏 Sample Calculation

Ripple voltage (Vr) for capacitor C:

Vr = I / (f × C)

For 0.2A current, 100Hz ripple, 470µF cap:

Vr = 0.2 / (100 × 470e-6) ≈ 4.25V → Use larger capacitance or higher frequency to reduce ripple.

🛒 Product Suggestion: Use India-Made Essentials

Stabilize your SMPS with capacitor kits and ferrite beads, all Made in India:

• 👉 Search Capacitor Kit – SmartXProKits

• 👉 Search Ferrite Bead – SmartXProKits

Shop now at SmartXProKits.in — Support our work and India’s innovation—buy from our Make in India site!