Question 4.69: OP AMP Circuit Analysis and Design (a) (A) Find the input-ou......
OP AMP Circuit Analysis and Design
(a) (A) Find the input-output relationship of the circuit in Figure P4-69.
(b) (D) Design a circuit that realizes the relationship found in (a) using only 10-kΩ resistors and one OP AMP.
(a) The circuit is connected as a subtractor in series with an inverting summer. The inputs to the subtractor are v_1 and v_O. The inputs to the summer are the output of the first stage and v_2. The following MATLAB code computes the gains for each stage and determines the overall input output relationship.
Script File
clear all
syms R v1 v2 vo
K1 = -2*R/R;
K2 = R/(R+2*R)*(R+2*R)/R;
K3 = -R/R;
K4 = -R/(R/2);
Eqn1 = 'va - (K1*v1+K2*vo)';
Eqn2 = 'vo - (K3*va+K4*v2)';
Soln = solve(Eqn1,Eqn2,'va','vo');
vo = simplify(Soln.vo)
vo = subs(vo)
vo =
-(K3*K1*v1+K4*v2)/(-1+K2*K3)
vo =
v1-v2
The circuit performs the function of a subtractor.
(b) The following circuit meets the specifications.
Answer:
Presented at right.
