The Problem :

Switch Mode Power Supplies (SMPS) are popular for their efficiency, but they generate heat. Without proper thermal modeling, this heat can damage components, reduce lifespan, or cause sudden failures—especially in compact or enclosed prototypes.

The Solution :

Thermal modeling helps estimate how hot your SMPS components will get and allows you to plan heat sinks, ventilation, or layout improvements. A simple way to start is by using the power loss (P) and thermal resistance (θJA) to estimate temperature rise.

Practical Example :

Imagine you’re using a MOSFET that dissipates 0.5W of power and has a junction-to-ambient thermal resistance of 62°C/W:

Temperature rise = 0.5W × 62°C/W = 31°C.

If your ambient is 40°C, your MOSFET will reach 71°C—still safe, but nearing thermal limits.

Sample Calculation :

Want to keep the device under 60°C in a 40°C room?

Max allowed temp rise = 20°C

Required power dissipation:

P = Temp rise / θJA = 20°C / 62°C/W ≈ 0.32W

You’ll need to reduce load or improve cooling!

Product Suggestions :

Boost your thermal performance with Made in India components:

• MOSFET

• Thermal Pad

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