Download (assuming ideal op-amps for all the following problems)

Mansoura University
Faculty of Engineering
Communication Engineering Department
third Year Communication
Electronic circuits
Sheet (1)
1) A differential amplifier connected in the circuit in Fig.1 has the parameters listed below
with
= 5 KΩ and
= 1 KΩ .
Input resistance
=1 MΩ
A= 60 dB
=25 Ω
Output resistance
=
a. Find the overall voltage gain
, current gain
sin(wt)
, and power gain
for the
amplifier , and express the result in dB
b. What is the amplitude
of the sinusoidal input signal needed to develop a 10 V
peak-to-peak signal at
c. Suppose that the previous amplifier has been designed to match the source and
load resistances (
i.
)
What is the amplitude of the input signal
needed to develop
a 10 V peak-to-peak signal at
ii.
How much power is dissipated in the amplifier when 0.5 W is
delivered to the load resistor
(assuming ideal op-amps for all the following problems)
2)
= 22 KΩ and
= 110 KΩ in the amplifier circuit in Fig.2
a. What is the output voltage if
=0?
b. What is the output voltage if dc signal
=0.22 V is applied to the circuit?
c. What is the output voltage if an ac signal
=0.15 sin 2500πt V
d. What is the output voltage if the input signal is
e. What is the input current
=0.22- 0.15 sin 2500πt
for parts (b),(c),(d)
f. What is the op-amp output current
for the input signals in parts (b),(c),(d)
g. What is the voltage at the inverting input of the op-amp for the input signals in
part (d)
3) For the circuit in Fig.3
a. What are the gain, input resistance, and output resistance if
=180 Ω and
=47
KΩ. Express the gain in dB
b. If the resistors have 10 percent tolerance , what are the worst-case values (highest
and lowest) of gain that could occur
Page 1
Mansoura University
Faculty of Engineering
Communication Engineering Department
third Year Communication
Electronic circuits
Sheet (1)
c. What are the resulting positive and negative tolerances on the voltage gain with
respect to the ideal value
d. What is the ratio of the largest to the smallest voltage gain
4) Write an expression for the output voltage
KΩ,
of the circuit in Fig.4 if
=47 KΩ,
=1 KΩ,
, and
,
=2
(note:
)
a. If
, find and plot
b. If
, find and plot
5) For the circuit in Fig.5 What is the output voltage
with the data input 0110 if
6) For the circuit in Fig.6
a. What is the gain of the circuit if
and
b. What is the input resistance presented to
c. What is the input resistance at terminal
d. What is the output voltage if
and
e. What is the output voltage if
f. Find
,
and
and
if
and
7) Find the voltage gain, input resistance, and output resistance for the circuits in Fig.7
8) For the circuit in Fig.8
a. What is the output current
if
and
. Assume
MOSFET is saturated
b. What is the minimum voltage
needed to saturate the MOSFET if
and
c. What must be the power dissipation rating of resistor R
Page 2
Mansoura University
Faculty of Engineering
Communication Engineering Department
Fig.1
Fig.2
Fig.3
Page 3
third Year Communication
Electronic circuits
Sheet (1)
Mansoura University
Faculty of Engineering
Communication Engineering Department
third Year Communication
Electronic circuits
Sheet (1)
Fig.4
Fig.5
Fig.6
Fig.8
Page 4
Mansoura University
Faculty of Engineering
Communication Engineering Department
Fig.7
Page 5
third Year Communication
Electronic circuits
Sheet (1)