Question

Given that the higher cut-off frequency of the cascaded network of 6 amplifiers is 2Mhz, find the higher cut-off frequency of one amplifier, if all amplifiers are similar.

(a) 5.7 Mhz

(b) 0.33 Mhz

(c) 12 Mhz

(d) 64 Mhz

I had been asked this question in exam.

This question is from Cascaded Amplifier in section General and Feedback Amplifiers of Analog Circuits

Answer 1

Right answer is (a) 5.7 Mhz

The explanation: fH = 2Mhz

fH = fH1 \(\sqrt{2^{1/N}}-1\)

fH1 = 2Mhz/√\(\sqrt{2^{1/6}}-1\) = 5.71 Mhz.