Tài liệu THE INVERTERS pptx

THE INVERTERS
DIGITAL GATES
Fundamental Parameters

Functionality

Reliability, Robustness

Area

Performance
»
Speed (delay)
»
Power Consumption
»
Energy
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Noise in Digital Integrated Circuits
V
DD
v(t)
i(t)
(a) Inductive coupling (b) Capacitive coupling
(c) Power and ground
noise
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction

DC Operation:
Voltage Transfer Characteristic
V(x)
V(y)
V
OH
V
OL
V
M

V
OH
V
OL
f
V(y)=V(x)
Switching Threshold
Nominal Voltage Levels
V(y)V(x)
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Mapping between analog and digital signals
"1"
"0"
V
OH
V
IH

V
IL
V
OL
Undefined
Region
V(x)
V(y)
V
OH
V
OL
V
IH
V
IL
Slope = -1
Slope = -1
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Definition of Noise Margins
V
IH
V
IL
Undefined
Region
"1"
"0"

V
OH
V
OL
NM
H
NM
L
Gate Output
Gate Input
Noise Margin High
Noise Margin Low
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
The Regenerative Property
(a) A chain of inverters.
v
0
, v
2
, ...
v
1
, v
3
, ... v
1
, v
3

, ...
v
0
, v
2
, ...
(b) Regenerative gate
f(v)
finv(v)
finv(v)
f(v)
(c) Non-regenerative gate
v
0
v
1
v
2
v
3
v
4
v
5
v
6
...
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction

Fan-in and Fan-out
N
M
(a) Fan-out N
(b) Fan-in M
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
The Ideal Gate
V
in
V
out
g=
−∞
R
i
=
∞
R
o
= 0
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
VTC of Real Inverter
0.0 1.0 2.0 3.0 4.0 5.0
V
in
(V)

1.0
2.0
3.0
4.0
5.0
V
out
(V)
V
M
NM
H
NM
L
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Delay Definitions
t
pHL
t
pLH
t
t
V
in
V
out
50%
50%

t
r
10%
90%
t
f
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Ring Oscillator
v
0
v
1
v
2
v
3
v
4
v
5
v
0
v
1
v
5
T = 2
×

t
p
×
N
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Power Dissipation
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
CMOS INVERTER
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
The CMOS Inverter:
A First Glance
V
DD
V
in
V
out
C
L
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
CMOS Inverters
Polysilicon

In
Out
Metal1
V
DD
GND
PMOS
NMOS
1.2 µm
=2λ
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
Switch Model of CMOS Transistor
R
on
|V
GS
| < |V
T
|
|V
GS
| > |V
T
|
|V
GS
|
Digital Integrated Circuits © Prentice Hall 1995

Introduction
Introduction
CMOS Inverter: Steady State Response
V
DD
V
DD
V
out
V
out
V
in
= V
DD
V
in
= 0
R
on
R
on
V
OH
= V
DD
V
OL
= 0
V

M
=
R
onp
)
f(R
onn
,
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
CMOS Inverter: Transient Response
V
DD
V
out
V
in
= V
DD
R
on
C
L
t
pHL
= f(R
on
.C
L

)
= 0.69 R
on
C
L
t
V
out
V
DD
R
on
C
L
1
0.5
ln(0.5)
0.36
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction
CMOS Properties

Full rail-to-rail swing

Symmetrical VTC

Propagation delay function of load
capacitance and resistance of transistors


No static power dissipation

Direct path current during switching
Digital Integrated Circuits © Prentice Hall 1995
Introduction
Introduction