Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

59
Willy Sansen 10-05 041 Noise performance of elementary transistor stages Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium [email protected]

Transcript of Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Page 1: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

41

Noi

se p

erfo

rman

ce

of e

lem

enta

ry tr

ansi

stor

stag

es

Will

y Sa

nsen

KU

Leuv

en, E

SAT-

MIC

AS

Leuv

en, B

elgi

umw

illy.

sans

en@

esat

.kul

euve

n.be

Page 2: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

42

SNR

and

SN

DR

v OU

T

v IN

0.1

% d

isto

rtio

n

1 %

dis

tort

ion

0.1%

SN

DR

SNR

00

Page 3: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

43

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g

Page 4: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

44

Noi

se v

ersu

s tim

e

t t

v N v N2

v N2

is th

e av

erag

e no

ise

pow

er

Ref

. Van

der

Ziel

(Pre

ntic

e H

all 1

954,

Wile

y 19

86),

Ott

(Wile

y 19

88)

Page 5: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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45

Noi

se v

ersu

s fre

quen

cy

v N2

f

dvN

2Noi

se d

ensi

ty V

2 /H

z

whi

te n

oise

1/f n

oise

f 1df

f 2

v 12

=

v N2

=

�dv N

2df

=

(f2-

f 1) d

v N2

f 1

f 2V R

MS

Inte

grat

ed n

oise

V RM

S/�H

z

Page 6: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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46

Noi

se o

f a r

esis

tor

is th

erm

al n

oise

RdvR

2

Rdi

R2

dvR

2 =

4kT

R d

f

is

whi

te

for R

= 1

k����

dvR

2=

4 nV

RM

S/

Hz

depe

nds

on T

, not

on

I R

at T

= 3

00 K

or 2

7oC

diR

2 =

=

d

f i

s w

hite

dvR

2

R2

4kT R

Page 7: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Inte

grat

ed N

oise

of R

esis

tor

-1

v out

dvR

s2

v in

RS

CL

BW

f

A

dvR

s2=

4kT

RS

dfB

W =

1��

RSC

L

�v R

s2=

dvR

s2

1 +

(f/ B

W) 2

0

Page 8: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Inte

grat

ed N

oise

of R

esis

tor

-2

BW

� 2B

Wn

f

A

�v R

s2=

dvR

s2

1 +

(f/ B

W) 2

0

BW

�dx

1 +

x 2

0

�� 2

==

v Rs2

=kT C

LC

L =

1pF

vR

s= 6

5 �V

RM

S

v Rs2

=4k

T R

SBW

� 2df

Page 9: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Noi

se d

ensi

ty v

s int

egra

ted

nois

e

BW

BW

n

f

A

�v R

s2=

dvR

s2

1 +

(f/ B

W) 2

0

�=

kT CL

dvR

s2=

4kT

RS

df

Noi

se d

ensi

ty (

V2/H

z) ~

RS

(or 1

/gm

)

Inte

grat

ed n

oise

(VR

MS)

~ 1

/CL

Page 10: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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A r

esis

tor

also

has

1/f

nois

e

RdvR

f2dv

Rf2

= V R

2

for R

= 1

k���w

ith 2

0 �

‘s o

f 50 ����

and

1 �m

wid

e an

d V R

= 0.

1 V

dvR

f2=

16

nVR

MS/

Hz

at 1

Hz

df fis

1/f

KF R

R�

AR

KF R

Si�

2 1

0 -2

1Sc

m2

KF R

poly

� 10

KF R

Si

V R+ -

Ref

. Van

dam

me,

ESS

DER

C ‘0

4

Page 11: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Noi

se o

f a d

iode

is sh

ot n

oise

I D

diD

2

diD

2 =

2q I D

df

is

whi

te

depe

nds

on I D

, not

on

T

for I

D=

50 �

Adi

D2

= 4

pAR

MS/

Hz

q =

1.6

10-1

9C

Page 12: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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A d

iode

als

o ha

s 1/f

nois

e

diD

f2 =

I D

For a

dio

de o

f AD

= 5

x 2

�m

= 1

0 �m

2an

d I D

= 0.

1 m

A

diD

f2=

1 nA

RM

S/

Hz

at 1

Hz

df fis

1/f

KF D A

D

KF D

� 10

-21

Acm

2

I D

diD

f2

Page 13: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

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Noi

se o

f a M

OST

r DS

g mv G

S

v GS

+ -

v out

+ -

v in+ -

diD

S2

dvG

2 =

4kT

RG

df

dvG

2R

G

diD

S2 =

d

f = 4

kT

gm

dfR

CH

4kT

2 3R

ef. V

an d

erZi

el, P

rent

ice

Hal

l 195

4, W

iley

1986

.

Page 14: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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MO

ST: e

quiv

alen

t inp

ut n

oise

: w

hite

dvie

q2 =

4kT

(Ref

f) d

f

R

eff=

+ R

G

r DS

g mv G

S

v GS

+ -

v in+ -dvie

q2R

G

v out

+ -

Hi F

req.

: di

ieq2

= (C

GS

)2dv

ieq2

is c

orre

late

d

g m2/3

Page 15: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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Poly

Gat

e re

sist

ance

rG

in a

MO

ST

Page 16: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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Subs

trat

e re

sist

ance

s rB

in a

MO

ST Ref

. Cha

ng, K

luw

er19

91

Page 17: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Noi

se b

y th

e B

ulk

resi

stan

ce

r DS

g mv G

S

v GS+ -

g mbv

BS

v BS

+ -

v inG+ -dvrG

2R

G

v inB

=0

+ -

dvrB

2R

B

r DS

g mv G

S

v GS+ -

v in+ -dvie

q2R

Gdv

ieq2

= 4

kT (R

eff)

df

Ref

f=

+ R

G+

RB

(n-1

)2g m2/

3

(n-1

) = C

D/C

ox=

g mb/

g m

Page 18: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

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Noi

se b

y th

e So

urce

res

ista

nce

r DS

g mv G

S

v GS+ -

v in

+ -dvie

q2R

G

dvie

q2 =

4kT

(Ref

f) df

Ref

f=

+ R

G+

RS

+ R

B(n

-1)2

g m2/3

RS

Noi

se o

f RS

= no

ise

RG

Page 19: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

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Noi

se b

y So

urce

res

isto

r R

i out

diM

2

diou

t2

Rdi

R2

v in g m

R >

> 1

i out

=v i

n R

diM

2 =

4kT

2/3

g m d

fdi

outM

2 = (g

mR

)2di

M2

diR

2 =

df

4kT R

diou

tR2

= di

R2

diou

t2 =

4kT R

(

+

1 )

df �

2/3

g mR

4kT R

df

dvin

2 =

4kT

R d

f

Page 20: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

420

MO

ST: e

quiv

alen

t inp

ut n

oise

: E

xerc

ise

dvie

q2 �

4kT

(

) d

f

r DS

g mv G

S

v GS

+ -

v in+ -dvie

q2

v out

+ -

g m2/3

dvie

q2 �

?fo

r ID

S=

65 �

A

Page 21: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

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dvie

qf2

=

r DS

g mv G

S

v GS

+ -

v in+ -dvie

qf2

RG

WL

Cox

2

KF F

v out

+ -

df fpM

OST

KF F

� 1

0-32

C2 /

cm2

nMO

STK

F F �

4 1

0-31

C2 /

cm2

pJFE

TK

F F �

10-

33C

2 /cm

2

W &

L in

cm

; Cox

inF/

cm2

MO

ST: e

quiv

alen

t inp

ut n

oise

: 1/

f noi

se

Page 22: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

422

Noi

se v

s cur

rent

: co

rner

freq

uenc

y

dvie

q2

ff c

hif c

lo

I DSl

ow

hite

noi

se ~

~

I DSh

i

Cor

ner f

requ

ency

~ g

m

1/f n

oise

~

g m1WL

WL1

Page 23: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

423

Noi

se v

s cur

rent

: ex

erci

se f c

dvie

q2

ff c

hif c

lo

I DSl

ow

hite

noi

se ~

I DSh

i

1/f n

oise

g m1

Ex. :

fc?

For I

DS

= 65

�A

; K

’ n=

60 �

A/V

2an

d L

= 1 �m

(0.3

5 �m

pro

cess

)f c

� 37

0 kH

z

Page 24: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

424

Noi

se se

en a

t the

Bul

k

dvie

q2dv

ieqb

2

dvie

q2 =

4kT

(

) d

f

dvie

qf2

=

WL

Cox

2

KF F

df f

g m2/3

n-1

= g mg m

b

dvie

qb2

= 4

kT (

)

df

dvie

qfb2

=

WL

Cox

2

KF F

df f

2/3

g m g mb2

g m2

g mb2

Page 25: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

425

Noi

se o

f a B

ipol

ar tr

ansi

stor

r og m

v BE

+vB

E

-

v out

+ -

v in+ -

diC

2

dvB

2 =

4kT

r Bdf

dvB

2r B

diB

2 =

2q

I Bdf

diC

2 =

2q

I Cdf

diB

f2 =

A

EB

KF B

I Bdf f

KF B

� 1

0-21

Acm

2

r �di

B2

C E

Ref

. Van

der

Ziel

(Pre

ntic

e H

all 1

954)

Page 26: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

426

Bip

olar

tran

s.: e

quiv

alen

t inp

ut n

oise

dvie

q2 =

4kT

(Ref

f) d

f

R

eff=

+ R

B +

RE

r og m

v BE

v out

+ -

g m1/2

diie

q2 =

di B

2 =

2q

I Bdf

+ v B

E

-

v in+ -dv

ieq2

RB

r �di

ieq2

Page 27: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

427

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or

�N

oise

of a

diff

eren

tial p

air

�C

apac

itive

noi

se m

atch

ing

Page 28: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

428

Noi

se o

f an

ampl

ifier

with

act

ive

load

v out

M1M2

v in

CL

dv22

dv12

dvB

2

+

If d

v B2

is

negl

igib

le :

diou

t2 =

g m12

dv12

+ g m

22 dv

22

dvie

q2 =

dv12

+dv

22 ()2

g m1

g m2

dvie

q2 =

dv12

(1 +

)

g m1

g m2

Smal

l gm

2: s

mal

l (W

/L) 2

or l

arge

(V G

S-V

T ) 2

dvie

q2

V B

Page 29: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

429

1/f N

oise

of a

mpl

ifier

with

act

ive

load

v out

M1

M2

v in

CL

dv2f

2

dv1f

2

dvB

2

+

If dv

B2

is

negl

igib

le :

dvif2

= dv

1f2

+dv

2f2 (

)2

g m

1

g m2

dvif2

= dv

1f2

[1 +

(

)2

()2

]

dvif2

has

min

imum

at

g m1

g m2

dv1f

dv2f

dvif2

= dv

1f2

[1 +

(

)2]

KF 1

KF 2

L 2L 1K

’ 1

K’ 2

L 1op

t= L

2�

10 L

2th

en d

v if2

= 2

dv1f

2

KF 2

KF 1

K’ 2

K’ 1

V B

Page 30: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

430

Noi

se fi

gure

of a

n am

plifi

er

v in+ -

dvS2

RS di

ieq2dv

ieq2

v out

+ -

AR

in=

NF

=

=

1 +

NS

+ N

A

NS

NA

NS

NF

= 1

+ 4k

T R

S df

dvie

q2+

RS2

diie

q2Vo

ltage

driv

e N

F ~

Cur

rent

driv

e N

F ~

RS1 RS

Page 31: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

431

Res

istiv

e no

ise

mat

chin

g

RS

NF

NS

NA

Rso

pt

=

100

r B=

100 �

Rso

pt=

dvie

q2

diie

q2

g m=

3.8

mS

Page 32: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

432

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g

Page 33: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

433

Noi

se o

f an

emitt

er fo

llow

er

i CE

v INRS

diie

2dv

ie2

v OU

T

CL

RT

A

dvA

2

diA

2I T

dvie

q2

dvie

q2 =

dvie

2 +

dvA

2 +

(RS

-)2

diie

2 +

dvS2

diT2

1 g m

diT2 +

di A

2

g m2

Page 34: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

434

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g

Page 35: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

435

Noi

se o

f a c

asco

deam

plifi

er

I B

+v o

ut

v in

M1

M2

dv22

dv12

dvie

q2

dvie

q2 =

dv12

+ dv

221

(gm

1 r o

1)2

�dv

12

Page 36: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

436

Inpu

t ref

erre

d no

ise

of a

cas

code

RL

+

v out

v in

i SR

Si N

v out

RL

g mr D

SRS

g mr D

S

v out i S

= g m

r DSR

S

v in i S

= R

S

v out i N

= r D

S

g mR

S

1 g m

g mr D

S>>

1

Page 37: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

437

Noi

se g

ains

in a

cas

code

RL

+

v out

v in

i SR

Si N

A

RL

r DS

g mr D

S

v out

=v i

n

i Seq i N

=g m

RS

1

i Nv o

ut=

g mr D

Sv i

ni S

RL RS

Cas

code

nois

e i N

is

only

neg

ligib

le i

f RS

is la

rge

!!!

Page 38: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

438

Noi

se o

f a fo

lded

cas

code

dv22

dvie

q2

dvie

q2 =

dv12

+ dv

22

+ d

v 32

1(g

m1

r o1)

2

I B1

v out

v in

M1

M2

CL

+

I B2

M3

dv32

dv12

dvB

2

(gm

3)2

(gm

1)2

Smal

l gm

3:

(W/L

) 3(V

GS-

V T) 3

If dv

B2

is n

eglig

ible

:

Page 39: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

439

Noi

se o

f a c

asco

dew

ith li

near

M1

I B

+

v out

v in

M1

linea

r

M2

dv22

dv12

dvie

q2

(Ron

1+

) d

f

V DS1

Av

= �

1g m

2 r o

2

Ron

1=

1

1(V

GS1

-VT)

2/3

g m2

I DS1

= 1

V DS1

(VG

S1-V

T)

�1

= V D

S1

V GS1

-VT

�1

< 0.

5

4kT

�12

dvie

q2=

Page 40: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

440

Smal

l-sig

nal m

odel

of a

cas

code

with

line

ar M

1

r o2

g m2v

2

v 2+ - v in

dv22

v out + -

+dv

ieq2

Ron

1

g m1v

in

CL

-

Ron

1=

1

1(V

GS1

-VT)

I DS1

= 1

V DS1

(VG

S1-V

T)

dv12

dv12

=4k

T R

on1

�12

v out

/ dv 2

= g

m2

r o2

(Ron

1+

) d

f2/

3g m

2

4kT

�12

dvie

q2=

dv22

=4k

T 2/

3g m

2v o

ut/ d

v 1= �

1g m

2 r o

2

Page 41: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

441

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g

Page 42: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

442

Noi

se o

f a c

urre

nt m

irro

r

1 : B

i ini o

ut

M1

M2

di22

di12

diin

2

diou

t2

diou

t2 =

di22

+ B

2(d

i in2

+ di

12 )

Smal

l gm

:

(W/L

)

(VG

S-V T

)

4kT

g m2

df2 3

=

Page 43: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

443

Noi

se o

f a c

urre

nt m

irro

r w

ith se

ries

R

i ini o

ut

M1

M2

di22

di12

diin

2

diou

t2di

out2

= di

22 + d

i R22

+

(di 1

2 + d

i R12 )

Smal

l gm

:

(W/L

)

(VG

S-V T

)

RR

1R

2di

R12

diR

22

(R1)

2

(R2)

2

Page 44: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

444

Noi

se o

f a c

urre

nt m

irro

r w

ith se

ries

R R1=

R2

diou

t2

RR

M

M

diou

t2=

8kT

R2

diou

t2=

4kTg

m2

(gm

2R2)

2

4 3

1/g m

4kT(

)g

m2d

f4 3

Bilo

tti, J

SSC

Dec

75,

516

-524

df

df

Page 45: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

445

Cur

rent

mir

ror

with

seri

es R

I out

M2di

outR

2di

outR

2 =

diou

t2 Smal

l gm

:

(W/L

)

(VG

S-V T

)

V G

R

M1

V G+ -

I out

diou

t2 (VG

S-V T

)(V

GS-

V T)

(W/L

)(W

/L)

Sam

e I o

ut&

sam

e V G

:

Page 46: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

446

Noi

se in

bip

olar

cur

rent

mir

ror

1 : B

i ini o

ut

M1

M2

M3 R

Noi

se a

dded

by

M3

:

diou

tM32

= 2q

I C3

df

Noi

se a

dded

by

R :

Bot

h ar

e di

vide

d by

32

to b

e ad

ded

to th

e ou

tput

and

are

thus

neg

ligib

le !

diou

tR2

= 4k

T/R

df

Page 47: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

447

Low

-noi

se c

urre

nt m

irro

r w

ith se

ries

R

I out

M2

diou

t22

1 M

OST

: di o

ut2

=

RM

1V G

1+ -

I out

diou

t12

Larg

e R

or V

G2

Sam

e I o

ut&

diff

eren

t VG

:

+ V G2

>VG

1

-

3 41 4

I out

diou

t2 =

diou

t12

+ di

out2

2 =

8kT 3

2Iou

t df

V GS-

V T

V G2-

V G1)

(V G

1-V T

9 161 4

+8k

T 32I

out d

fV G

1-V T

2 M

OST

s: V

G2 >V

G1

Page 48: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

448

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g

Page 49: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

449

Noi

se o

f diff

eren

tial p

air

V DD V S

S

v OU

T

-

I B

RL

RL

+-

dv12

dv22

v OU

TA

dvie

q2

+ -+-

A+ -+-

v OU

T

M1

M2

+

dvie

q2 =

2 dv

12

Page 50: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

450

Noi

se o

f diff

eren

tial p

air

with

act

ive

load

V DD

V SSv O

UT

CL

M1

M2

M3

M4

+-

I B

di12

di22

di42

di32

dvie

q2 =

=di

out2

g m12

dvie

q2 =

2dv 1

2 (1

+

)

g m12

2di 1

2 +2d

i 32

g m1

g m3

Smal

l gm

3:

(W/L

) 3

(VG

S-V T

) 3

Page 51: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

451

Diff

eren

tial p

air

with

sour

ce r

esis

tors

I BR

RR

R

I B/2

I B/2

diou

t2 =

2 4k

T Rdf

dvin

2 =

2 (4

kT R

df)

g mR

>> 1

diB

2 is

neg

ligib

le

diou

t2 =

2 ( 4k

T Rdf

+ d

i B2

)

diB

2 =

4kT

2/3

gm

Bdf

dvin

2 =

2 (4

kT R

df)

(1 +

2/3

gm

BR

)

Page 52: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

452

Noi

se o

f an

opam

p

v OU

TA

dvR

12

+-

dvie

q2=

dvR

12 +

dvR

22 (

) 2

+ dv

A2

(1 +

) 2 �

dv R

12 +

dvA

2

dvA

2

dvR

22R

2

dvie

q2

R1

dvie

q2=

�dv

out2

( )

2R

2

R1

R1

R2

dvou

t2 =

dv R

12 (

) 2

dvou

t2 =

dv R

22

R2

R1

R2

R1

dvou

t2 =

dv A

2 (1

+) 2

R

1

R2

Page 53: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

453

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

diff

eren

tial p

air

�N

oise

of a

cur

rent

mirr

or�

Cap

aciti

ve n

oise

mat

chin

g

Ref

.: Z.

Y.C

hang

, W.S

anse

n, L

ow-n

oise

wid

e-ba

nd a

mpl

ifier

s, K

luw

erA

P, 1

991

Page 54: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

454

Cap

aciti

ve-s

ourc

e am

plifi

er

v out

v in

Ai in

Cf

Ca

Ca

Av

= C

f

Ca

I DS

CG

S=

kW

k�

2 fF

/�m

Wop

t?

ID

Sopt

? S

/Nop

tfo

r Vin

= 10

mV R

MS

?

Ca

= 5

pFC

f= 1

pF

Page 55: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

455

Cap

aciti

ve n

oise

mat

chin

g -1

Cf

Ca

I DS

CG

S

Cf

Ca

dvie

q2

I DS

CG

S

dvi2 v G

S�

0

v out

v out

v iv out

=C

f+C

a+C

GS

Cf

v GS

� 0

v ieq

v out

=C

a Cf

No

Mill

er

with

CD

G !!

!

Page 56: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

456

Cap

aciti

ve n

oise

mat

chin

g -2

v in

dvie

q2 =

Cf

Ca

dvie

q2

I DS

CG

S

dvi2

Ca2

(Cf+

Ca+

CG

S)2

dvie

q2 =

Ca2

(Cf +

Ca

+ kW

) 2

dvi2

=38k

Tg m1

df

g m=

2 K

’ nLW

(VG

S-V T

)

WL38k

T2

K’ n

(VG

S-V T

)1

Page 57: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

457

Cap

aciti

ve n

oise

mat

chin

g -3

dvie

q2 =

Ca2

(Cf +

Ca

+ kW

) 2

WL38k

T2

K’ n

(VG

S-V T

)1

dvie

q2

Wop

tW

dvop

t2

Wop

t=

k

Cf +

Ca

g mC

GS

Noi

se m

atch

ing

whe

re

CG

S=

Cf +

Ca

Ope

ratin

g po

int

Page 58: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

458

Cap

aciti

ve n

oise

mat

chin

g -4

dvie

q2

Wop

tW

dvop

t2

Wop

t=

k

Cf +

Ca

CG

Sopt

I DSo

pt,

g mop

t

dvop

t2 =

438k

Tg m

opt

df

BW

n=

B

W=

=

2�

2�A

vf T

4Av

1C

GSo

pt

g mop

tN

opt

S=

10 m

V RM

S

dvop

t2 B

Wn

Page 59: Willy Sansen KULeuven, ESAT-MICAS Leuven, Belgium

Will

y Sa

nsen

10-0

5 0

459

Tab

le o

f con

tent

s

�D

efin

ition

s of

noi

se�

Noi

se o

f an

ampl

ifier

�N

oise

of a

follo

wer

�N

oise

of a

cas

code

�N

oise

of a

cur

rent

mirr

or�

Noi

se o

f a d

iffer

entia

l pai

r�

Cap

aciti

ve n

oise

mat

chin

g