7.3 Suppose a power transistor has a rated maximum power dissipation of 150 W at case temperatures less than 25°C. The m
Posted: Tue Jun 07, 2022 9:23 am
7.3 Suppose a power transistor has a rated maximum power dissipation of 150 W at case temperatures less than 25°C. The maximum junction temperature that it can withstand is 200°C. The thermal resistance between the junction and case is 0.86. The transistor has a heat sink with a thermal resistance of 3 which is bonded to the case using a thermal paste that has a thermal resistance of 0.5 °C. °C 7.3.1 What is the maximum allowable power dissipation given that the amplifier forms part of a sensor system in a boiler room where the ambient temperature is 40°C? What will the temperature of the case and of the heat sink be? 7.3.2 Suppose you needed the transistor to safely dissipate 45 W at an ambient temperature of 30°C, would the existing heat sink be sufficient? If not, what maximum thermal resistance would be required for the heat sink?