Tài liệu Circuits & Electronics P25 pptx

6.002 Fall 2000 Lecture
1
25
6.002
CIRCUITS
AND
ELECTRONICS
Violating the Abstraction Barrier
6.002 Fall 2000 Lecture
2
25
Case 1: The Double Take
Problem
R
i
V
O
V
“0”
Æ
“1”
t
O
V
“0”
“1”
t
O
V
“0”
“1”

observed
expected
in forbidden region!
huh?
6.002 Fall 2000 Lecture
3
25
(a) DC case
R
i
V
O
V
1
V
very high
impedance,
like open
circuit
OK
DCV5V
i
=
DCV5V
O
=
DCV5V
1
=
6.002 Fall 2000 Lecture

4
25
t
V5.2=
O
V
t
i
V
(b) Step
not ok!
t
1
V
looks ok!
b.1
b.3
b.2
V0
V5
0=
t
0=t
0=t
T
T2
V5
V5
R
i

V
O
V
1
V
very high
impedance,
like open
circuit
O
V
6.002 Fall 2000 Lecture
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25
R
i
V
....
instantaneous R divider
finite propagation speed
of signals
characteristic
impedance
→R
T2
T
5
2.5
0
V5

0
V5
0
V5