Voltage Regulator Heat Calculator
Calculate power dissipated as heat by a linear voltage regulator and the resulting junction temperature.
V
V
A
°C/W
°C
Power Dissipated
3.50 W
Junction Temperature200.0 °C
Temperature Rise175.0 °C
Power Dissipated vs Input Voltage
Linear Regulator Heat
Formulas
P = (V_in - V_out) x I_load
T_junction = T_ambient + P x Theta_JA
Keep junction temperature below the maximum rating (usually 125-150C). Use a heat sink to reduce thermal resistance.
Example Calculation
12 V to 5 V regulator at 0.5 A, 50 C/W thermal resistance, 25C ambient.
- 01P = (12 - 5) x 0.5 = 3.5 W
- 02T_rise = 3.5 x 50 = 175C
- 03T_junction = 25 + 175 = 200C (exceeds limits!)
Frequently Asked Questions
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