Transistor nMOSQchannel = CV

C = Cg = oxWLtox = CoxWL

V = Vgc ndash Vt = (Vgs ndash Vds2) ndash Vt

v = E (mobility)E = VdsL

Time for carrierto cross channelt = L v

n+ 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 channelndash How much time t each carrier takes to cross

channel

ox 2

2

ds

dsgs t ds

dsgs t ds

QItW VC V V VL

VV V V

ox = WCL

nMOS Operation

Cutoff Linear SaturatedVgs 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 processbull WL= 42 nmnmbull tox=40Aringbull 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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 channelndash How much time t each carrier takes to cross

channel

ox 2

2

ds

dsgs t ds

dsgs t ds

QItW VC V V VL

VV V V

ox = WCL

nMOS Operation

Cutoff Linear SaturatedVgs 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 processbull WL= 42 nmnmbull tox=40Aringbull 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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 SaturatedVgs 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 processbull WL= 42 nmnmbull tox=40Aringbull 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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 processbull WL= 42 nmnmbull tox=40Aringbull 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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-welln-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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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 LinearB Saturation LinearC Saturation SaturationD Linear SaturationE 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