McGill University
Faculty of Engineering
Department of Electrical and Computer Engineering
ECSE-330A – Introduction to Electronics
Examiner: Dr. David V. Plant; _____________________
Associate Examiner: Dr. Ramesh Abhari______________________
Date: Thursday, December 7
th
, 2006
Time: 9:00 – 12:00
Calculator: Faculty Standard
Pertinent Information:
1) This is a closed-book examination, no notes permitted. There are 3 pages of equations
provided at the back of the examination.
2) The examination consists of 7 problems; you must answer all 7 problems.
3) The examination is worth 75 total points
4) The examination consists of 11 pages, including this page and the equations pages;
please ensure you have a COMPLETE examination paper.
5) Only the Faculty Standard Calculator is permitted.
6) Questions may be completed in any order, however ensure that you clearly identify
which part of which question you are attempting.
Do NOT turn in this exam with your exam booklet

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Question #1 (10 points)
a)
[2 pts]
A voltage amplifier with an input resistance of 7.2k
Ω
is connected to a voltage
source whose resistance is 5k
Ω
. Through measurements, it has been determined that
this amplifier has a gain of 20.4 V/V when open-circuited at the output and 10.2 V/V
when a 1k
Ω
resistance is connected at the load. Find the values of A
vo
, R
OUT
for this
amplifier.
--------------------------------------------------------------
A
transresistance
amplifier “AMP1” has R
IN
= 500
Ω
, R
OUT
= 750
Ω
, and R
VO
= 50 V/A.
A
voltage
amplifier “AMP2” has R
in
= 7.2k
Ω
, A
vo
= -10V/V and R
OUT
= 500
Ω
.
They are connected as shown in the figure below.
Assume the
constant voltage drop model
for all diodes and
R
S
= 5k
Ω
and R
L
= 1k
Ω
.
I
in
V
out
+5V
-3V
V
X
Voltage Amp
(AMP2)
Transresistance
Amp (AMP1)
R
S
R
L
I
S
b)
[2 pts]
Redraw the circuit, replacing the amplifiers with their equivalent circuits.
(Leave the diodes and sources as they are).
For parts c), d) and e), assume V
out
= 0 and V
X
= 0 when I
S
= 0.
c)
[3 pts]
Draw the current-to-voltage transfer characteristic (v
out
vs. i
s
) of this circuit,
making sure to show the limits of the linear region. (Hint: it will help to first sketch v
x
vs. i
s
and compute v
out
/v
x
)
d)
[1 pt]
Based on your transfer characteristic, what input current results in the
maximum symmetric voltage swing at V
out
?