hw4_sol - Solutions to HOMEWORK#4 1a Rout = 1 g m2 Avo = g...

Solutions to HOMEWORK #4
1a.
3
10
1
1 2
2
1
2
1
1
2
=
⋅
=
=
=
⋅ =
=
vo D
m
D
m
m
D
D
m
m
m
out m vo
m
out
A I
g
I
g
g
I
I
g
g
g
R g A
g
R
b.
5
2
1 4
3 2
2
3
10 67 . 5
10
3
10 89 . 1 2
2
−
− −
−
−
× = =
× = ⋅ =
=
m D
dB L m
L
m
dB
g I
V f C g
C
g
f
π
π
I
D
= 5.67×10
-5
A
I
TAIL
= 2 I
D
= 1.134×10
-4
A
Using I
D
/W vs 2/(g
m
/I
D
) plots, find
8 . 18
2
=
W
I
D for g
m2
/I
D
= 10/3
W
2
= I
D
/18.8 = 3um
18 . 2
1
=
W
I
D for g
m1
/I
D
= 10
W
1
= I
D
/2.18 = 26um
g
m1
= g
m1
/I
D
× I
D
= 5.67×10
-4
1/V
g
m2
= g
m2
/I
D
× I
D
= 1.89.×10
-4
1/V
c. SPICE DECK
* Hw 4, Number 1
*.param k = '2'
.param k = '1'
+ curr = 'k*113.4u'
+ w1 ='k*26u'
+ w2 ='k*3u'

+ len =.5u
vic vic 0 1.5
vid vid 0 ac 1
e1 vip vic vid 0 0.5
e2 vic vim vid 0 0.5
itail vdd vs curr
vdd vdd 0 0
m1a vom vip vs vs pch214 W='w1' L='len'
m1b vop vim vs vs pch214 W='w1' L='len'
m2a 0 0 vom vom pch214 W='w2' L='len'
m2b 0 0 vop vop pch214 W='w2' L='len'
cl1 vop 0 100f
cl2 vom 0 100f
.op
.ac dec 100 1k 10g
.tf v(vop) vid
.options post brief
.lib '/usr/class/ee214/lib/ee214_hspice.txt' nominal
.end
.op *Note that SPICE says transistors are in cutoff. Obviously, that