Question

What is the purpose of heat sink in transistor circuit?

(a) Provide sufficient heat for transistor

(b) Absorb excess heat from transistor

(c) Keep transistor at desired temperature range

(d) All of the mentioned

I had been asked this question in homework.

My question comes from Heat Sink for Power Transistor-1 in chapter Power Amplifier of Analog Circuits

Answer 1

Right answer is (d) All of the mentioned

For explanation I would say: Heat sink in a transistor circuit performs a major function of keeping temperature of transistor at a desired range and also absorbs excess heat. Self heating occurs in a transistor due to power dissipated at the collector junction. This can cause junction temperature to rise and further increases collector current, and such a process may damage the device.