Thermal Resistance Calculator

Calculate the maximum power an IC can handle w.r.t its maximum junction temperature, and calculate an output load current for use with voltage regulators.

TAMB °C Ambient temperature. eg. Room temperature
TJMAX
°C Maximum junction temperature
See IC datasheet. Maximum allowed temp of semiconductor junction within the case.
RθJC °K/W Junction-to-case thermal resistance
See IC datasheet.
RθB °K/W Case-to-heatsink thermal resistance.
Thermal resistance of heat-transfer pad between IC and heatsink. Enter 0 if no heatsink.
RθHA °K/W Heatsink-to-ambient thermal resistance.
See heatsink datasheet. Enter case-to-ambient temp from IC datasheet if a heatsink is not being used.
Output Voltage V Output voltage from switching regulator.
Efficiency % IC efficiency, for calculating regulator load current.
Max power dissipation  
Max load current  
TAMB °C Ambient temperature. eg. Room temperature
TJMAX
°C Maximum junction temperature
See IC datasheet. Maximum allowed temp of semiconductor junction within the case.
RθJC °K/W Junction-to-case thermal resistance
See IC datasheet.
RθB °K/W Case-to-heatsink thermal resistance.
Thermal resistance of heat-transfer pad between IC and heatsink. Enter 0 if no heatsink.
RθHA °K/W Heatsink-to-ambient thermal resistance.
See heatsink datasheet. Enter case-to-ambient temp from IC datasheet if a heatsink is not being used.
Input Voltage V Input voltage to linear regulator.
Output Voltage V Output voltage from linear regulator.
Max power dissipation  
Max output current