Question

If 1/h12 = 10 for a C.E. stage, what is the value of the base to collector capacitance, after Miller multiplication, at the output side?

(a) 1.1Cµ

(b) 1.2Cµ

(c) 2.1Cµ

(d) 2.2Cµ

I got this question during a job interview.

My question comes from Effect of Various Capacitors on Frequency Response topic in portion Transistor Frequency Response of Analog Circuits

Answer 1

Right choice is (a) 1.1Cµ

The best explanation: At the output side of a C.E. stage, Cµ gets multiplied by a factor of (1+1/Av) where Av is the voltage gain. 1/h12 is nothing but Av. Hence, the value changes to 1.1Cµ.