Home work 2 ED
1
Assume OA1 , OA2 ideal.
a) For vI∈[-12V;12V], find the expression of vO1(vI) and
plot the VTC vO1(vI). What is the application of the circuit
assuming vO1 as output?
b) For vI∈[-12V;12V], find the expression of vO2(vI) and
plot the VTC vO2(vI). What is the application of the circuit
assuming vO2 as output?
c) Plot the VTC vO(vI) for vI∈[-12V;12V]. Assuming vI(t)=
11 sin ωt [V], plot vI(t) and vO(t). What is the application of
the circuit?
2
a) Draw, qualitatively, the VTC vO(vI) of the circuit.
What is the function of the circuit?
b) Find the expressions and values of the following
parameters from VTC: VOH; VOL; VTh,H; VTh,L. Redraw the VTC vO(vI) according to the numerical values
obtained.
c) Assume vI(t) is a triangular wave, with no D.C.
component, of 10V amplitude (vI∈[-10V;10V]). Plot
vI(t) and vO(t). How does vO(t) change if the amplitude
of vI reduces to 5V?
3 Assume OA – ideal
a) What is the expression of vO(vI1,vI2, vI3) assuming
OA in the active region for R1=R2=R3=R4=15KΩ?
b) Now consider vI3=0. Find the relationship
between R1, R2, R3, R4 in order to obtain the expression :
vO=3(vI2-vI1) ? For what range of values of (vI2-vI1) does OA
work in the active region? Deduce the expresions for input vI1
resistances considering the input only vI1 (with vI2 set to
zero), respectively only vI2 (with vI1 set to zero), and the
output resistance of the circuit.
c) If vI3=0 and vO=3(vI2-vI1) plot vO(t) assuming
vI1(t)=2sinω0t[V]+1V si vI2(t)=-3sinω0t[V] +4V. What is the
vI2
application of the circuit?
R2
+VPS=12V
R1
OA
-VPS=-12V
R3
vO
R4
vI3