# Chapter - 22 : FET AMPLIFIERS¶

## Ex 22.1 Pg 601¶

In [1]:
from __future__ import division

ID=5*10**-3#
VDD=10#
RD=1*10**3#
RS=500#
VS=ID*RS#
print 'VS=%0.2f V'%VS
VD=VDD-ID*RD#
print 'VD=%0.2f V'%VD
VDS=VD-VS#
print 'VDS=%0.2f V'%VDS
VGS=-VS#
print 'VGS=%0.2f V'%VGS

VS=2.50 V
VD=5.00 V
VDS=2.50 V
VGS=-2.50 V


## Ex 22.2 Pg 602¶

In [3]:
from __future__ import division
from math import sqrt
RD=56*10**3#
RG=1*10**6#
IDSS=1.5*10**-3#
VP=-1.5#
VD=10#
VDD=20#
ID=VD/RD#
print 'ID=%0.2f mA'%(ID*10**3)
#ID=IDSS*(1-(VGS/VP))**2
VGS=VP*(1-sqrt(ID/IDSS))#
print 'VGS=%0.2f V'%VGS
VS=VGS#
R1=(-VS/ID)-4*10**3#
print 'R1=%0.2f kohm'%(R1*10**-3)

ID=0.18 mA
VGS=-0.98 V
R1=1.50 kohm


## Ex 22.3 Pg 603¶

In [4]:
from __future__ import division

ID=1.5*10**-3#
VDS=10#
IDSS=5*10**-3#
VP=-2#
VDD=20#
#ID=IDSS*(1-(VGS/VP))**2
VGS=VP*(1-(ID/IDSS))#
VS=-VGS#
RS=(VS/ID)#
print 'RS=%0.2f ohm'%RS
RD=((VDD-VDS)/ID)-RS#
print 'RD=%0.2f kohm'%(RD*10**-3)

RS=933.33 ohm
RD=5.73 kohm


## Ex 22.5 Pg 604¶

In [6]:
from __future__ import division
from math import sqrt
VP=5#
IDSS=12*10**-3#
VDD=12#
ID=4*10**-3#
VDS=6#
VGS=VP*(1-sqrt(ID/IDSS))#
VS=VGS#
RS=VS/ID#
print 'RS=%0.2f ohm'%RS
RD=VDS/ID#
print 'RD=%0.2f kohm'%(RD*10**-3)

RS=528.31 ohm
RD=1.50 kohm


## Ex 22.6 Pg 605¶

In [8]:
from __future__ import division
IDSS=10*10**-3#
VDD=20#
IDQ=IDSS/2#
print 'IDQ=%0.2f mA'%(IDQ*10**3)
VDSQ=VDD/2#
print 'VDS=%0.2f V'%VDSQ
VGS=-2.2#
RD=(VDD-VDSQ)/IDQ#
print 'RD=%0.2f kohm'%(RD*10**-3)
RS=-VGS/IDQ#
print 'RS=%0.2f ohm'%(RS)

IDQ=5.00 mA
VDS=10.00 V
RD=2.00 kohm
RS=440.00 ohm


## Ex 22.7 Pg 606¶

In [9]:
from __future__ import division

VDD=20#
RD=2.5*10**3#
RS=1.5*10**3#
R1=2*10**6#
R2=250*10**3#
ID=4*10**-3#
VG=(R2*VDD)/(R1+R2)#
VS=ID*RS#
VGS=VG-VS#
print 'VGS=%0.2f V'%VGS
VD=VDD-ID*RD#
VDS=VD-VS#
print 'VDS=%0.2f V'%VDS

VGS=-3.78 V
VDS=4.00 V


## Ex 22.8 Pg 607¶

In [10]:
from __future__ import division

gm=4*10**-3#
RD=1.5*10**3#
AV=-gm*RD#
print "Av=%0.2f"%AV

Av=-6.00


## Ex 22.9 Pg 608¶

In [12]:
from __future__ import division

gm=2.5*10**-3#
rd=500*10**3#
RD=10*10**3#
rL=(RD*rd)/(rd+RD)#
print 'rL=%0.2e ohm'%rL
AV=-gm*rL#
print "Av=%0.2f"%AV

rL=9.80e+03 ohm
Av=-24.51


## Ex 22.10 Pg 608¶

In [13]:
from __future__ import division

gm=2*10**-3#
rd=40*10**3#
RD=20*10**3#
RG=100*10**6#
rL=(RD*rd)/(RD+rd)#
Av=-gm*rL#
print "Av=%0.2f"%Av
Ri=RG#
print 'Ri=%0.2f Mohm'%(Ri*10**-6)
Ro=rL#
print 'Ro=%0.2f kohm'%(Ro*10**-3)

Av=-26.67
Ri=100.00 Mohm
Ro=13.33 kohm


## Ex 22.11 Pg 609¶

In [14]:
from __future__ import division

#e.g 22.11
gm=2*10**-3#
rd=10*10**3#
RD=50*10**3#
rl=(rd*RD)/(rd+RD)#
Av=-gm*rl#
print "Av=%0.2f"%Av

Av=-16.67


## Ex 22.12 Pg 610¶

In [15]:
from __future__ import division

RD=100*10**3#
gm=1.6*10**-3#
rd=44*10**3#
Cgs=3*10**-12#
Cds=1*10**-12#
Cgd=2.8*10**-12#
rl=(RD*rd)/(RD+rd)#
Av=-gm*rl#
print "Av=%0.2f"%Av

Av=-48.89


## Ex 22.13 Pg 610¶

In [16]:
from __future__ import division

gm=4500*10**-6#
RD=3*10**3#
RL=5*10**3#
vin=100*10**-3#
ID=2*10**-3#
rl=(RD*RL)/(RD+RL)#
VO=gm*rl*vin#
print 'VO=%0.2f V'%VO

VO=0.84 V


## Ex 22.14 Pg 611¶

In [17]:
from __future__ import division

#e.g 22.14#
gm=4*10**-3#
RD=1.5*10**3#
RG=10*10**6#
rs=500#
rl=RD#
AV=-(gm*rl)/(1+gm*rs)#
print "Av=%0.2f"%AV
RL=100*10**3#
rL=(RD*RL)/(RD+RL)#
AV=-(gm*rL)/(1+gm*rs)#
print "Av=%0.2f"%AV

Av=-2.00
Av=-1.97


## Ex 22.15 Pg 612¶

In [19]:
from __future__ import division

RD=1.5*10**3#
RS=750#
RG=1*10**6#
IDSS=10*10**-3#
VP=-3.5#
IDQ=2.3*10**-3#
VGSQ=-1.8#
gmo=-2*IDSS/VP#
gm=gmo*(1-(VGSQ/VP))#
rL=RD#
AV=-(gm*rL)/(1+gm*RS)#
print "Av=%0.2f"%AV
AV=-gm*rL#
print "Av=%0.2f"%AV

Av=-1.35
Av=-4.16


## Ex 22.16 Pg 614¶

In [20]:
from __future__ import division

gm=8000*10**-6#
RS=10*10**3#
RG=100*10**6#
(1/gm)#
AV=RS/(RS+(1/gm))#
print "AV=%0.2f"%AV
Ri=RG#
Ro=1/gm#
print 'Ro=%0.2f ohm'%Ro

AV=0.99
Ro=125.00 ohm


## Ex 22.17 Pg 616¶

In [21]:
from __future__ import division

vin=2*10**-3#
gm=5500*10**-6#
R1=1*10**6#
R2=1*10**6#
RS=5000#
RL=2000#
(1/gm)#
AV=RS/(RS+(1/gm))#
print "AV=%0.2f "%AV
Ri=(R1*R2)/(R1+R2)#
print 'Ri=%0.2f Mohm'%(Ri*10**-6)
Ro=(RS/gm)/(RS+1/gm)#
print 'Ro=%0.2f ohm'%Ro
Vo=(RL/(RL+Ro))*(AV*vin)#
print 'Vo=%0.2f mV'%(Vo*10**3)

AV=0.96
Ri=0.50 Mohm
Ro=175.44 ohm
Vo=1.77 mV


## Ex 22.18 Pg 618¶

In [22]:
from __future__ import division

gm=2500*10**-6#
Ri=2000#
RD=10000#
AV=gm*RD#
print "AV=%0.2f "%AV
Ri1=(Ri/gm)/(Ri+1/gm)#
print 'Ri1=%0.2f ohm'%Ri1

AV=25.00
Ri1=333.33 ohm


## Ex 22.19 Pg 618¶

In [23]:
from __future__ import division

gm=2*10**-3#
rd=50*10**3#
Rs=1*10**3#
Ro=(Rs/gm)/(Rs+1/gm)#
print 'Ro=%0.2f ohm'%Ro

Ro=333.33 ohm


## Ex 22.20 Pg 619¶

In [24]:
from __future__ import division

#e.g 22.20
gmo=5*10**-3#
RD=1*10**3#
Rs=200#
ID=5*10**-3#
Ri1=(Rs/gmo)/(Rs+1/gmo)#
print 'Ri1=%0.2f ohm'%Ri1
Vs=ID*Rs#
print 'Vs=%0.2f V'%Vs
VGS=Vs#
IDSS=2*ID#
VGSo=(-2*IDSS)/ID#
gm=gmo*(1-VGS/-VGSo)#
Av=gm*RD#
print "Av=%0.2f "%Av

Ri1=100.00 ohm
Vs=1.00 V
Av=3.75