SMPS Efficiency at Light Loads – A Quick Guide
🔋 The Problem :
Switch Mode Power Supplies (SMPS) are known for efficiency—but at light loads, they often waste more power than they deliver! This happens because internal switching losses and quiescent currents dominate when the load draws just a few milliamps. Result? Poor battery life or unnecessary heat.
🧰 The Solution :
To fix this, choose SMPS controllers with burst mode or eco-mode, which reduce switching frequency at light loads. Alternatively, add a dummy load resistor to keep the SMPS within a more efficient range—but that’s a trade-off between efficiency and stability.
📦 Practical Example :
Let’s say you’re powering a BLE sensor that draws only 2mA most of the time. Your 12V SMPS rated for 1A runs inefficiently here. Swap it with a buck converter module using an MP1584 chip that supports burst mode—it consumes less idle power and your battery lasts longer.
🔢 Sample Calculation :
Say your SMPS uses 50mW even with no load, and your sensor draws 2mA at 3.3V:
Ouch! A burst-mode converter improves this drastically.
🛒 Product Suggestion :
Try ‘MP1584 buck converter’ or ‘low load SMPS’ from our catalog:
Support our work and India’s innovation—buy from our Make in India site!
