Transistor nMOS Q channel = CV C = C g = ox WL/t ox = C ox WL V = V gc – V t = (V gs – V ds /2)...
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Transistor nMOS Q channel = CV C = C g = ox WL/t ox = C ox WL V = V gc – V t = (V gs – V ds /2) – V t v = E (mobility) E = V ds /L Time for carrier to cross channel: t = L / v n+ n+ p-type body W L t ox SiO 2 gate oxide (good insulator, ox = 3.9) polysilicon gate C ox = ox / t ox
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Transcript of Transistor nMOS Q channel = CV C = C g = ox WL/t ox = C ox WL V = V gc – V t = (V gs – V ds /2)...
Transistor nMOSQchannel = CV
C = Cg = oxWLtox = CoxWL
V = Vgc ndash Vt = (Vgs ndash Vds2) ndash Vt
v = E (mobility)
E = VdsL
Time for carrier
to cross channel
t = L vn+ n+
p-type body
W
L
tox
SiO2 gate oxide(good insulator ox = 39)
polysilicongate
Cox = ox tox
nMOS Linear I-V
bull Now we knowndash How much charge Qchannel is in the channel
ndash How much time t each carrier takes to cross
channel
ox 2
2
ds
dsgs t ds
dsgs t ds
QI
tW VC V V VL
VV V V
ox = W
CL
nMOS Operation
Cutoff Linear Saturated
Vgs lt Vt Vgs gt Vt
Vds lt VgsndashVt
Vgs gt Vt
Vds gt Vgs ndashVt
Ids 0 Ids = (VgsndashVtndashVds2)Vds Ids = (VgsndashVt)2
Esempiobull 180 nm process
bull WL= 42 nmnmbull tox=40Aring
bull cm2(Vs)
bull Vt = 04V
= Cox WL = 180 (39885 10-14 Fcm)(4010-8)
=155 V
1) Idsmax (Vgs=1V) = 155 VV)
2) Ids(Vgs=2V Vds=1V) = 155 V
I-V CharacteristicsVgsn5
Vgsn4
Vgsn3
Vgsn2Vgsn1
Vgsp5
Vgsp4
Vgsp3
Vgsp2
Vgsp1
VDD
-VDD
Vdsn
-Vdsp
-Idsp
Idsn
0
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
nMOS Linear I-V
bull Now we knowndash How much charge Qchannel is in the channel
ndash How much time t each carrier takes to cross
channel
ox 2
2
ds
dsgs t ds
dsgs t ds
QI
tW VC V V VL
VV V V
ox = W
CL
nMOS Operation
Cutoff Linear Saturated
Vgs lt Vt Vgs gt Vt
Vds lt VgsndashVt
Vgs gt Vt
Vds gt Vgs ndashVt
Ids 0 Ids = (VgsndashVtndashVds2)Vds Ids = (VgsndashVt)2
Esempiobull 180 nm process
bull WL= 42 nmnmbull tox=40Aring
bull cm2(Vs)
bull Vt = 04V
= Cox WL = 180 (39885 10-14 Fcm)(4010-8)
=155 V
1) Idsmax (Vgs=1V) = 155 VV)
2) Ids(Vgs=2V Vds=1V) = 155 V
I-V CharacteristicsVgsn5
Vgsn4
Vgsn3
Vgsn2Vgsn1
Vgsp5
Vgsp4
Vgsp3
Vgsp2
Vgsp1
VDD
-VDD
Vdsn
-Vdsp
-Idsp
Idsn
0
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
nMOS Operation
Cutoff Linear Saturated
Vgs lt Vt Vgs gt Vt
Vds lt VgsndashVt
Vgs gt Vt
Vds gt Vgs ndashVt
Ids 0 Ids = (VgsndashVtndashVds2)Vds Ids = (VgsndashVt)2
Esempiobull 180 nm process
bull WL= 42 nmnmbull tox=40Aring
bull cm2(Vs)
bull Vt = 04V
= Cox WL = 180 (39885 10-14 Fcm)(4010-8)
=155 V
1) Idsmax (Vgs=1V) = 155 VV)
2) Ids(Vgs=2V Vds=1V) = 155 V
I-V CharacteristicsVgsn5
Vgsn4
Vgsn3
Vgsn2Vgsn1
Vgsp5
Vgsp4
Vgsp3
Vgsp2
Vgsp1
VDD
-VDD
Vdsn
-Vdsp
-Idsp
Idsn
0
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
Esempiobull 180 nm process
bull WL= 42 nmnmbull tox=40Aring
bull cm2(Vs)
bull Vt = 04V
= Cox WL = 180 (39885 10-14 Fcm)(4010-8)
=155 V
1) Idsmax (Vgs=1V) = 155 VV)
2) Ids(Vgs=2V Vds=1V) = 155 V
I-V CharacteristicsVgsn5
Vgsn4
Vgsn3
Vgsn2Vgsn1
Vgsp5
Vgsp4
Vgsp3
Vgsp2
Vgsp1
VDD
-VDD
Vdsn
-Vdsp
-Idsp
Idsn
0
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
I-V CharacteristicsVgsn5
Vgsn4
Vgsn3
Vgsn2Vgsn1
Vgsp5
Vgsp4
Vgsp3
Vgsp2
Vgsp1
VDD
-VDD
Vdsn
-Vdsp
-Idsp
Idsn
0
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
CMOS Inverter
OutIn
VDD
PMOS
NMOS
n-well
n-well contact (n+)
p+ diffusions
polysilicon
n+ diffusions
substrate contact (p+)
polysilicon contacts
diffusion contacts
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
DC Transfer Curvebull For a given Vin
ndash Plot Idsn Idsp vs Vout
ndash Vout must be where |currents| are equal in
bull Transcribe points onto Vin vs Vout plot
Vin5
Vin4
Vin3
Vin2Vin1
Vin0
Vin1
Vin2
Vin3Vin4
VoutVDD
CVout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
Operating Regions C
Vout
0
Vin
VDD
VDD
A B
DE
Vtn VDD2 VDD+Vtp
Region nMOS pMOSA Cutoff Linear
B Saturation Linear
C Saturation Saturation
D Linear Saturation
E Linear Cutoff
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
Beta Ratio
bull If p n 1 switching point will move from VDD2
Vout
0
Vin
VDD
VDD
051
2
10p
n
01p
n
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
Inverter a Carico Resistivo
Vout
I
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
Inverter a Carico Attivo
Vout
I
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
-
