Microelectronic Circuits - KOCw

Preview:

Citation preview

Microelectronic Circuits - Fifth Edition Sedra/Smith Copyright 2004 by Oxford University Press, IncFundamentals of Microelectronics Behzad Razavi Copyright 2009 by John Wiley & Sons, Inc

2

1

2

2121

2

1

2

1

2121

1

1

11

1

11

E

E

E

EEEE

E

E

E

E

EEEE

E

ii

iiiii

iii

iiiii

i

Small-Signal Model

Em

Cm

in

out

EmEmREin

EmRE

Cm

out

C

outm

Rgr

Rgvv

Rgr

vRvgrvvvvv

Rvgrvv

Rgvv

Rvvg

11

11

,

then, rgm /11

이득감소

idv

idv

(resistance seen between two bases)

1,, mem grgr

odv CmmCeC RggRrR

ee

ide Rr

vi22

1)22/(

eeid Rrv

Small-Signal Model

Interestingly, this gain is equal to the total load resistance to ground divided by 1/gm plus the total resistance placed in series with the emitter.

Em

Cv

Em

Cmv

Rg

RA

RgRgA

1

1

gmRE >>1인 경우, Av는 IC에 의존하지 않는다.

12 cc vv

Cm Rg21

Cm Rg21

differential output => Acm=0, CMRR=