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Question 19.2: A transistor has a thermal resistance from junction to case ...

A transistor has a thermal resistance from junction to case of 1.5 °C/W. If the transistor is fitted with a washer and mounting kit having a thermal resistance of 1.75 °C/W, and a heatsink of 2.25 °C/W, determine the total thermal resistance that exists between junction and ambient.

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Applying equation (5) gives:

θ_{JA} = θ_{JC} + θ_{CS} + θ_{SA} = 1.5 + 1.75 + 2.25 = 5.5 °C/W

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