THE INVERTERS

1
THE INVERTERS
2
DIGITAL GATES Fundamental Parameters

• Functionality
• Reliability, Robustness
• Area
• Performance
• Speed (delay)
• Power Consumption
• Energy

3
Noise in Digital Integrated Circuits
4
DC Operation Voltage Transfer Characteristic
5
Mapping between analog and digital signals
6
Definition of Noise Margins
7
The Regenerative Property
8
Fan-in and Fan-out
9
The Ideal Gate
10
VTC of Real Inverter
11
Delay Definitions
12
Ring Oscillator
13
Power Dissipation
14
CMOS INVERTER
15
The CMOS Inverter A First Glance
16
CMOS Inverters
1.2
m
m
2l
Out
In
GND
17
Switch Model of CMOS Transistor
18
CMOS Inverter Steady State Response
19
CMOS Inverter Transient Response
20
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

21
Voltage TransferCharacteristic
22
PMOS Load Lines
23
CMOS Inverter Load Characteristics
24
CMOS Inverter VTC
25
Simulated VTC
26
Gate Switching Threshold
27
MOS Transistor Small Signal Model
28
Determining VIH and VIL
29
Propagation Delay
30
CMOS Inverter Transient Response
31
CMOS Inverter Propagation Delay
32
Computing the Capacitances
33
CMOS Inverters
1.2
m
m
2l
Out
In
GND
34
The Miller Effect
35
Computing the Capacitances
36
Impact of Rise Time on Delay
37
Delay as a function of VDD
38
Where Does Power Go in CMOS?
39
Dynamic Power Dissipation
2
Energy/transition C
V
L
dd
2
Power Energy/transition
f
C
V

f
L
dd
Not a function of transistor sizes!
Need to reduce C
, V
, and
f
to reduce power.
L
dd
40
Impact ofTechnology Scaling
41
Technology Evolution
42
Technology Scaling (1)
Minimum Feature Size
43
Technology Scaling (2)
Number of components per chip
44
Propagation Delay Scaling
45
Technology Scaling Models
46

Scaling Relationships for Long Channel Devices
47

Scaling of Short Channel Devices