Digital Integrated Circuits A Design Perspective

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Digital Integrated CircuitsA Design Perspective
Jan M. Rabaey Anantha Chandrakasan Borivoje
Nikolic
The Inverter
February 24, 2004
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Class Announcements

• Next lecture is hands-on CAD tutorial.
• Homework 1 is still due today.
• Homework solutions will be discussed _at_ end of
  todays lecture.

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The CMOS Inverter A First Glance
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CMOS Inverter
N Well
PMOS
2l
Contacts
Out
In
Metal 1
Polysilicon
NMOS
GND
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Two Inverters
Share power and ground Abut cells
Connect in Metal
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CMOS InverterFirst-Order DC Analysis
VOL 0 VOH VDD VM f(Rn, Rp)
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CMOS Inverter Transient Response
V
V
DD
DD
R
p
V
V
out
out
C
C
L
L
R
n
V
V
V
0
5
5
in
DD
in
(a) Low-to-high
(b) High-to-low
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Voltage TransferCharacteristic
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PMOS Load Lines
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CMOS Inverter Load Characteristics
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CMOS Inverter VTC
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Switching Threshold as a function of Transistor
Ratio
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Determining VIH and VIL
A simplified approach
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Inverter Gain
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Gain as a function of VDD
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Simulated VTC
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Impact of Process Variations