Question

How do we calculate the value of IC in the CE short circuit current frequency response model?

(a) IC = hre × IB

(b) IC = -hre × IB

(c) IC = hfe × IB

(d) IC = -hfe × IB

I have been asked this question during an internship interview.

My query is from The CE Short Circuit Current Frequency Response topic in section High Frequency Transistor of Electronic Devices & Circuits

Answer 1

The correct choice is (c) IC = hfe × IB

Easy explanation: The collector current of a common emitter (CE) amplifier can be expressed in terms of hybrid parameters in the CE short circuit current frequency response model. It is expressed as the product of hfe × IB. This is the same for approximate hybrid models as well.