# LectureKx

Ηλεκτρονική - Συσκευές

2 Νοε 2013 (πριν από 4 χρόνια και 6 μήνες)

68 εμφανίσεις

Lecture K

No lectures on Thursdays anymore! Yeah!

Mid
-
term in ~3 weeks. Covers all materials we
covered up that date (lectures and labs)

(Proposal due in 5 weeks)

Our Trusty LF356 contains about a dozen transistors
(BJTs and FETs)

Modern CPUs and GPUs contain well over 1 billion
transistors. Some memory chips even several 10
billions (mostly FETs)!

(Sorry. No circuit diagram for this one…)

Moore’s Law

Curve shows ‘Moore’s Law’:

Transistor count doubling
every two years

Analogy of current in n and p
-
doped semiconductors

Energy

Momentum

n
-
doped

p
-
doped

un
-
doped

(“intrinsic”)

Electrons
carry the
current.

“Holes”
carry the
current.

Traffic jam!
Current
cannot
flow.

Based on the V
CE

vs. I
C

plot on the board,
what is the current gain
h
fe
?

L1

A)
1

B)
10

C)
100

D)
200

E)
1000

What is V
out

for an emitter follower?

L2

A)
I
B
R
E

B)
V
in

C)
10 V
-

0.6 V

D)
V
in

+ 0.6 V

E)
V
in

0.6 V

What is V
out

for a common emitter amplifier?

L5

A)
V
cc
-

h
fe

R
C
I
B

B)
V
in
-

h
fe

R
C
I
B

C)
V
cc
-

R
C
I
B

D)
V
in
-

R
C
I
B

E)
I
donno
.

21

For the (properly biased) input voltage
signal shown below, which of the
following choices best represents the
output voltage signal for the circuit at
right?

22

V
in

is a 1

kHz signal with peak
-
to
-
peak amplitude of 1

V.

A)

A
> B > C

B)

B
> A > C

C)

B
> C > A

D)

B
> A = C

E)

C

> A > B

Rank the three circuits according
to the peak
-
to
-
peak amplitude of
V
out
.

23

For V
in

as shown, rank
outputs 1, 2, and 3
according to peak
-
to
-
peak amplitude from
largest to smallest

A)
1 > 2 > 3

B)
1 > 2 = 3

C)
2 = 3 > 1

D)
2 > 3 > 1

E)
3 > 2 = 1

24

Suppose a 1
-
kΩ resistor
is added to the circuit as
shown at right.

A)
Increase

B)
Decrease

C)
Remain the same

D)
Not enough information

When the resistor is
-
to
-
peak amplitude of
output 1 (for the same
input signal) will:

25

V
in

is a 1

kHz signal with peak
-
to
-
peak amplitude of 1

V.

A)
A > B > C

B)
B > A > C

C)
B > C > A

D)
B > A = C

E)
C

> A > B

Rank the three circuits according
to the peak
-
to
-
peak amplitude of
V
out
.