← antimony labs / Power Electronics
v1.0.0
Lesson 04

Thermal Design & Runaway

Prevent smoke. Estimate conduction vs switching loss of a MOSFET and predict junction temperatures under ambient load.

1. Transistor Metrics

on-resistance [R_ds(on)] 15 mΩ
switching time [t_sw] 25 ns

2. Environment & Load

load current [I_load] 10 A
drain voltage [V_ds] 24 V
thermal resistance [θ_JA] 40 °C/W
ambient temp [T_amb] 25 °C
Conduction Loss
Switching Loss
Total Power Loss
Junction Temp

Junction Thermal Rise Bar

175°C 100°C 25°C
Junction Temp (T_j)
Rise (Delta T)
Thermal State