Question

Consider the circuit shown. The input VI = 10sin2π10^6t. Calculate the duty cycle of the output.

(a) 0.43

(b) 0.065

(c) 0.36

(d) 0.5

I had been asked this question in semester exam.

I'm obligated to ask this question of Op-Amp Characteristics in division Op-amps and its Applications of Analog Circuits

Answer 1

Right option is (c) 0.36

Explanation: Duty cycle for a signal = Duration when output is VSat/Total period

Let input = VI = 10 sinθ

The output goes to +VSat whenever the input VI crosses amplitude of 4V.

Thus 4 = 10sinθ

Θ = sin^-1 0.4 = 0.411 rad = 23.57°

The duty cycle = [180 – θ – θ]/360 = 180-47.14/360 = 0.36.