1-GHz and 2.8-GHz CMOS Injection-locked Ring Oscillator...

31
Rafael J. Betancourt-Zamora, Shwetabh Verma and Thomas H. Lee Department of Electrical Engineering Stanford University http://www-smirc.stanford.edu/ 1-GHz and 2.8-GHz CMOS Injection-locked Ring Oscillator Prescalers

Transcript of 1-GHz and 2.8-GHz CMOS Injection-locked Ring Oscillator...

Raf

ael J

. Bet

anco

urt

-Zam

ora

, Sh

wet

abh

Ver

ma

and

Th

om

as H

. Lee

Dep

artm

ent o

f Ele

ctric

al E

ngin

eerin

gS

tanf

ord

Uni

vers

ityht

tp://

ww

w-s

mirc

.sta

nfor

d.ed

u/

1-G

Hz

and

2.8

-GH

z C

MO

S

Inje

ctio

n-l

ock

ed R

ing

O

scill

ato

r P

resc

aler

s

Ou

tlin

e

•In

tro

du

ctio

n•In

ject

ion

Lock

ing

The

ory

•C

ircui

t Im

plem

enta

tion

•M

easu

red

Res

ults

•C

oncl

usio

n

•U

nd

erst

and

th

e In

ject

ion

-lo

ckin

g

mec

han

ism

•G

rasp

th

e lim

itat

ion

s o

f In

ject

ion

-lo

cked

Fre

qu

ency

Div

ider

s

•D

esig

n In

ject

ion

-lo

cked

Fre

qu

ency

D

ivid

er u

sin

g a

Rin

g O

scill

ato

r

Go

als

Mo

tiva

tio

n:

Low

-pow

er F

req

uen

cy S

ynth

esis

•F

req

uen

cy s

ynth

esiz

ers

are

imp

lem

ente

d u

sin

g P

LL

s.

•M

ajo

r so

urc

es o

f p

ower

dis

sip

atio

n a

re t

he

VC

O a

nd

F

req

uen

cy D

ivid

er.

320

MH

z C

MO

S P

LL

[V.K

aen

el’9

6]90

0 M

Hz

CM

OS

RE

CE

IVE

R[D

arab

i’00]

÷8

QI

LN

A

VC

O

500µ

A

300µ

A40

0µA

300µ

A

100µ

A

150µ

A

Q I

÷2

÷N

PF

DC

P &

LF

UP

DN

VC

OF

RE

F

FO

UT

2µA

10µ A

240µ

A50

µ A

800µ

A

Fre

qu

ency

Div

ider

Pow

er T

rad

e-o

ff

•W

e pr

opos

e a

tech

niqu

e in

whi

ch p

ower

d

ecre

ases

with

div

isio

n ra

tio.

÷2

200µ

A10

0µA

100µ

A

÷2

÷2

900

MH

z45

0 M

Hz

225

MH

z11

2.5

MH

z

TOTA

L P

OW

ER

200µ

A30

0µA

400µ

A

PO

WE

R IN

CR

EA

SE

S W

ITH

DIV

ISIO

N R

AT

IO

[Dar

abi’0

0]

Ou

tlin

e

•In

trod

uctio

n

•In

ject

ion

Lo

ckin

g T

heo

ry•C

ircui

t Im

plem

enta

tion

•M

easu

red

Res

ults

•C

oncl

usio

n

Rin

g O

scill

ato

r M

od

el

V O

R L

CL

ωP

1R

LC

--------

-- L=

HS

j ω()

HO

1j ω

ωP

⁄+

--------

--------

--------

--=

•N

egle

ct fe

edfo

rwar

d ze

ro

I TAI

L

BA

RK

HA

US

EN

CR

ITE

RIA

•N

eces

sary

con

ditio

ns fo

r os

cilla

tion

Hj ω

O(

)1

Hj ω

O(

)∠

180°

=

SM

AL

L-S

IGN

AL

MO

DE

L

PH

AS

E C

ON

DIT

ION

GA

IN C

ON

DIT

ION

Rin

g O

scill

ato

r M

od

el (

II)

ωP

ω0 π n---

ta

n

--------

---------

=

N-S

TAG

E M

OD

EL

Hj ω(

)H

On

1j

ω ωo

------

π n---

tan

+

n----

--------

--------

--------

--------

--------

=H

O1

π n---

tan

2+

PH

AS

E C

ON

DIT

ION

GA

IN C

ON

DIT

ION

n2

>V O

•ω

0 is

free

-run

ning

osc

illat

or fr

eque

ncy.

•E

ach

stag

e co

ntrib

utes

π/ n

to th

e ph

ase.

Rin

g O

scill

ato

r M

od

el (

III)

EX

AM

PL

E

nH

p

32.

000.

58 ω

0

41.

41ω

0

51.

241.

38 ω

0

Hjω(

)H

On

1j

ω ωo

------

π n---

tan

+

n----

--------

--------

--------

--------

--------

= •D

C g

ain

Η0

decr

ease

s w

ith n

umbe

r of

sta

ges.

•P

oles

ωp

coin

cide

with

ω0

only

for

n=4.

V O

Inje

ctio

n-l

ock

ed R

ing

Osc

illat

or

R L

CL

ωR

F

VB

IAS

EX

AM

PL

E:

3-st

age,

Div

ide

by 4

ωω

RF

4--------

=

ω RF

•A

n os

cilla

tor c

an b

e in

ject

ion-

lock

ed to

a h

arm

onic

of

the

free

-run

ning

osc

illat

ion

freq

uenc

y.

Reg

ener

ativ

e D

ivid

er [

Mill

er 1

939]

•C

omm

only

use

d w

here

the

freq

uenc

y of

ope

ratio

n is

ver

y hi

gh,

beyo

nd w

hat c

an b

e ac

hiev

ed w

ith fl

ip-f

lop

base

d ci

rcui

ts.

•Fr

eque

ncy

mul

tiplie

r ca

n re

pres

ent n

on-li

near

ities

pre

sent

in

the

circ

uit.

•U

sed

a m

odel

sim

ilar

to M

iller

’s, s

ince

the

lock

ing

mec

hani

sms

are

iden

tical

.

ω RF

H(j

ω)

3

ωR

F3 4-----

ωR

ωω

RF

4--------

=

FR

EQ

. MU

LT.

EX

AM

PL

E:

Div

ide

by 4

Mo

del

for

Inje

ctio

n-l

ock

ed F

req

uen

cy D

ivid

er

n-s

tag

e L

PF

H(j

ω)

LO

Po

rtω

= ω R

F/M

RF

Po

rt

Dif

fere

nti

al P

air’

sN

on

-lin

eari

ty

Mix

er

-1

LO

+L

O-

I TA

ILω R

F

DC

+ ω R

F| ω

RF

- (M

+1)ω

|| ω

RF

- (M

-1)ω

|

ω

MIX

ER

•D

iffer

entia

l-pai

r si

ngle

-bal

ance

d m

ixer

•In

ject

ed ω

RF in

to th

e ta

il de

vice

FIL

TE

R•

Sup

pres

s pr

oduc

ts >

ω•

VO

is s

inus

oida

l (sm

all n

) .

ω , 3

ω , 5

ω ...

Mo

del

for

Inje

ctio

n-l

ock

ed F

req

uen

cy D

ivid

er (

II)

3-st

age

LP

F

H(j

ω)

LO

Po

rtω

= ω

RF/ 4

RF

Po

rt

Dif

fere

nti

al P

air’

sN

on

-lin

eari

ty

Mix

er

-1

LO

+L

O-

I TAIL

ω RF

DC +

ωR

F| ω

RF -

5ω|

| ωRF

- 3ω

|

ω

•W

ith n

o in

ject

ion,

ω =

ω0.

ω , 3

ω , 5

ω ...

EX

AM

PL

E:

3-st

age,

Div

ide

by 4

Mix

er

∆ V

∆ II B

IAS

VSA

T

-IB

IAS

-VSA

T

2IR

F

•T

he d

iffer

entia

l-pai

r is

non

-line

ar w

ith o

dd s

ymm

etry

. •

Non

-line

arity

pro

duce

s od

d ha

rmon

ics

at 3

ω, 5

ω, e

tc.

•I T

AIL

is m

odul

ated

by

ω a

nd it

s ha

rmon

ics.

LO

Po

rt

RF

Po

rt

Mix

er

LO

+L

O-

I TA

ILω R

F

ω, 3

ω, 5

ω ...

I TA

IL =

I RF

cos(

ω RFt

+ α

) + I B

IAS

VS

AT

WL⁄

() T

AIL

WL⁄

() D

IFF

--------

--------

--------

--------

VO

DT

⋅=

V0

cos(

ωt)

I TAI

L

Mix

er (

II)

LO

Po

rt

Mix

er ω , 3

ω , 5

ω ...

Ck

1 k π------

1– ()

k1

–(

)2 ⁄

0 =

odd

k

othe

rwis

e

Fo

uri

er C

oef

fici

ents

of

Πt ()

I TA

IL⋅

ρ s =

V0/

VSA

T >

> 1

(Sq

uar

e W

ave)

DE

FIN

E S

WIN

G R

AT

IO

Mix

ing

Fu

nct

ion

Π(t

)

V0

cos(

ωt)

I TA

IL

Lin

eari

ze P

has

e o

f H

(jω

)

ω

Hjω(

)∠

ω Ο

−π

d φ/d

ω H

j ω()

∠–π

≅n

2π n------

sin 2

--------

--------

-------

∆ω ω0

--------

⋅+

∆ω

ωω

O–

=

Filt

er

Hj ω(

)H

On

1j

ω ωo

------

π n---

tan

+

n----

--------

--------

--------

--------

--------

=

n-s

tag

e L

PF

H(j

ω)

-1| ω

RF

- 5ω

|| ω

RF

- 3ω

|

ω

Use

Rin

g O

scill

ato

r M

od

el

Des

crib

ing

Fu

nct

ion

An

alys

is

•If

VO

is la

rge,

then

the

inje

ctio

n lo

ckin

g dy

nam

ics

are

dete

rmin

ed b

y th

e ph

ase

rela

tions

hip

arou

nd th

e lo

op (

phas

e-lim

ited)

and

ther

efor

e w

e ca

n ig

nore

the

ampl

itude

exp

ress

ion.

η iC

M1

–C

M1

+–

()

αsi

n

C1

η iC

M1

–C

M1

++

()

αco

s+

--------

--------

--------

--------

--------

--------

--------

--------

--------

--------

--

at

anH

j ω∠–

π–=

η iI R

F

2I B

IAS

--------

--------

=

INJE

CT

ION

WR

ITE

PH

AS

E E

XP

RE

SS

ION

AR

OU

ND

TH

E L

OO

P

MIX

ER

FIL

TE

R

FIN

D S

OL

UT

ION

FO

R α

∈ (

- π, π

].

EF

FIC

IEN

CY

LR

4

n2

π n------

sin

--------

--------

-------

k 0

1k 1

2–

--------

--------

-----

atan

k 0η i

CM

1–

CM

1+

– C1

--------

--------

--------

--------

----=

k 1η i

CM

1–

CM

1+

+ C1

--------

--------

--------

--------

-----

=

•F

unct

ion

of in

ject

ion

effic

ienc

y η i

, and

the

mag

nitu

de o

f the

F

ourie

r co

effic

ient

s C

M-1

and

CM

+1.

•F

or s

mal

l val

ues

of in

ject

ed s

igna

l the

lock

ing

rang

e in

crea

ses

linea

rly w

ith th

e in

ject

ed s

igna

l str

engt

h.

WH

ER

E

Lo

ckin

g R

ang

e o

f In

ject

ion

-lo

cked

Rin

g O

scill

ato

r

Lim

ited

Inje

ctio

n E

ffic

ien

cy a

nd

Par

asit

ics

•Li

mite

d in

ject

ion

effic

ienc

y du

e to

sho

rt-c

hann

el e

ffect

s an

d ta

il de

vice

non

-line

arity

.

VR

F

VB

IAS

CPA

R

•S

hunt

pat

h fo

r I R

F r

educ

ing

the

inje

ctio

n ef

ficie

ncy

at h

igh

freq

uenc

ies.

TAIL

PA

RA

SIT

ICS

INJE

CTO

R N

ON

-ID

EA

LIT

IES

VR

F

VB

IAS

I DS

KV

RF

VO

DT

+(

)γ⋅

=

η iV

RF

2V

OD

T----

--------

----γ⋅

=

γ =

1 -

2

SH

OR

T-C

HA

NN

EL

–0.3

–0.2

–0.10

0.1

0.2

Sw

ing

Ra

tio, ρ

s=V

o/V

sat

24

68

10

Normalized Coefficients

C3/C/C

1

C5/C/C

1

Lim

ited

Mix

er G

ain

•T

he a

ssum

ptio

n th

at th

e m

ixer

’s s

witc

hing

func

tion

is a

squ

are

wav

e is

ver

y ac

cura

te if

the

swin

g ra

tio ρ

s >

> 1

.

•A

s ρ s

get

s sm

alle

r, th

e no

rmal

ized

coe

ffici

ents

Ck/

C1

are

sign

ifica

ntly

sm

alle

r, th

us d

egra

ding

the

lock

ing

rang

e.

00.

51

1.5

22.

53

3.5

4024681012141618

VR

F/V

OD

Locking Range (%)

ab

c

Exa

mp

le:

5-st

age,

Mo

du

lo-8

Rin

g O

scill

ato

r

(a)I

deal

(ph

ase-

limite

d) c

ase

(b)C

ompr

essi

on d

ue to

Inje

ctor

non

-line

arity

(sq

uare

-law

dev

ice)

(c)E

ffect

s of

Inje

ctor

non

-line

arity

and

tail

para

sitic

s (5

0% lo

ss)

Ou

tlin

e

•In

trod

uctio

n

•In

ject

ion

Lock

ing

The

ory

•C

ircu

it Im

ple

men

tati

on

•M

easu

red

Res

ults

•C

oncl

usio

n

5-st

age

Inje

ctio

n-l

ock

ed R

ing

Osc

illat

or

Fre

qu

ency

Div

ider

•U

sed

mod

ified

cro

ss-c

oupl

ed

sym

met

ric lo

ad b

uffe

rs.

•R

F s

igna

l inj

ecte

d at

the

tail

of

the

first

buf

fer (

sing

le-b

alan

ced

mix

er).

•T

he b

uffe

r st

ages

beh

ave

as

the

H(jω

) fil

ter.

+_

BR

OPA

MP

VB

IAS

VC

TL

Vdd

ωB

1

VR

F

B4

B3

B2

RE

PLI

CA

BIA

SIN

JEC

TIO

N-L

OC

KE

D R

ING O

SC

ILLA

TORB

5B

O

OU

T B

UF

FE

R

RB

IAS

VR

F

VB

IAS

VC

TL

Die

Mic

rog

rap

h:

5-st

age

Rin

g O

scill

ato

r D

ivid

er

RIN

GO

SC

ILLA

TOR

BIA

S

VR

F

OUTBUF

VO

UT

VO

UT

•Fa

bric

ated

3 a

nd 5

-sta

ge

ring

osci

llato

rs.

•0.

24-µ

m C

MO

S

•0.

012

mm

2 of

are

a

Ou

tlin

e

•In

trod

uctio

n

•In

ject

ion

Lock

ing

The

ory

•C

ircui

t Im

plem

enta

tion

•M

easu

red

Res

ult

s•C

oncl

usio

n

Res

ult

s

Inje

cted

Fre

quen

cyFr

ee-r

unni

ng F

requ

ency

Pha

se N

oise

@10

0KH

z

5-st

age

ILF

D1.

0 G

Hz

125

MH

z-1

10 d

Bc/

Hz

3-st

age

ILF

D2.

8 G

Hz

700

MH

z-1

06 d

Bc/

Hz

Inp

ut L

ock

ing

Ran

ge

M

odul

o-2

M

odul

o-4

M

odul

o-6

M

odul

o-8

12.7

MH

z (-

3dB

m)

32 M

Hz

(-3d

Bm

)17

MH

z (-

3dB

m)

20 M

Hz

(-3d

Bm

)

125

MH

z (-

3dB

m)

56

MH

z (-

5dB

m)

no-lo

ckno

-lock

Pow

er d

issi

pat

ion

Vdd

Ico

re I

bias

Cor

e po

wer

Pow

er e

ffici

ency

1.5

V23

3 µA

108

µA35

0 µW

2.86

GH

z/m

W

3.0

V33

1 µA

661

µA99

3 µW

2.82

GH

z/m

W

0.5

11.

52

2.5

33.

54

0

0.51

1.52

2.53

[ 0] d

iv8

[ 0] d

iv4

[ 3] d

iv8

[11]

div

8

[13]

div

128

[ 9] d

iv2

[15]

div

8 [13]

div

128

[14]

div

8

Fre

quen

cy, G

Hz

Power Efficiency, GHz/mW

•[0

] 5-s

tage

(di

v-8)

= 2

.86

GH

z/m

W @

1GH

z

•[0

] 3-s

tage

(di

v-4)

= 2

.82

GH

z/m

W @

2.8G

Hz

Pow

er E

ffic

ien

cy o

f In

ject

ion

-lo

cked

Rin

g O

scill

ato

r

•S

mal

l sw

ing

ratio

(ρs

≈ 3−

4) c

ause

d re

duct

ion

in m

ixer

gai

n.

Nee

d to

incr

ease

out

put s

win

g an

d re

duce

VS

AT.

Wh

at W

e L

earn

ed

•La

rge

tail

devi

ce (

W/L

=10

.2/1

) ca

used

loss

of I

RF.

Nee

d to

lo

wer

tail

node

par

asiti

cs to

incr

ease

the

inje

ctio

n ef

ficie

ncy.

•R

eson

atin

g ta

il w

ith a

n in

duct

or [ W

u, IS

SC

C’0

1]

is n

ot p

ract

ical

at s

ub-G

Hz

freq

uenc

ies.

LO

CK

ING

RA

NG

E C

OM

PAR

ISO

N

5-st

age

(div

-8)

@ 1

GH

z3-

stag

e (d

iv-4

) @

2.8

GH

z

TH

EO

RY

9%34

%

SIM

ULA

TIO

N5%

17%

TE

ST

2%2%

Ou

tlin

e

•In

trod

uctio

n

•In

ject

ion

Lock

ing

The

ory

•C

ircui

t Im

plem

enta

tion

•M

easu

red

Res

ults

•C

on

clu

sio

n

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