Problem 1
For each of the circuits below,
1. Determine analytical expressions for rin and rout
2. Based upon the results found in (1), determine whether the circuit is best
characterized as a voltage, current, transconductance, or transresistance amplifier
3. Based upon the result in (2), determine an analytical expression for the
proportionality constant of the dependent source in the 2-port model (i.e. if answer to
(2) was a transconductance amplifier, determine an analytical expression for Gm )
input
VDD
VBIAS
M1
M2
output
output
input
M1
M2
(a)
(b)
VDD
RX
input
M1
output
VBIAS
M2
(c)
VDD
VDD
VBIAS
M3
VBIAS3
M3
output
VBIAS2
M2
input
M1
output
VBIAS1
M1
M2
input
(d)
(e)
VDD
VDD
M3
M3
output
input
M1
input
M1
output
M2
(f)
M2
(g)
VDD
VBIAS1
VDD
VBIAS1
M3
M3
output
input
input
M1
M1
output
VBIAS2
VBIAS2
M2
(h)
M2
(i)
Problem 2
VDD
VDD
VDD
M2
M1
M6
output
VBIAS
M5
input
RY
M3
M4
VDD  5V , V BIAS  2.2V
RY  73k
W
8.2 m W
24.6 m W
33.2 m
)1 
, ( )2 
, ( )3 
L
1m
L
1m
L
2 m
W
111.2 m W
500 m W
82 m
( )4 
, ( )5 
, ( )6 
L
2 m
L
4 m
L
1m
(
Note: Use EE 105 technology file for transistor process parameters
1. Calculate the bias currents flowing through each branch and the bias voltages at each
node (except for the output) for the circuit above.
2. Determine the output range Vo ,min to Vo ,max over which all transistors remain in
saturation.
3. Assume, next, that the following are added to the input and output of the circuit above
Cs
is
Rs
input
CL
RL
output
C s and C L are large capacitors that act as short circuits for the sinusoidal smallsignals. However, at DC, capacitors act as open circuits. Hence, by including
capacitors C s and C L , one is able to introduce the small-signal input source and load
without affecting the bias conditions of the circuit (as calculated in (1)).
Assume that Rs  250k and RL  750k .
Derive analytical expressions and compute numerical values for rin and rout for the
resulting circuit.
4. Derive an analytical expression and compute the numerical value for R m (i.e.
transresistance) for the 2-port model representing the amplifier.
5. Using the 2-port model to represent the amplifier, derive an analytical expression and
voutput
compute the numerical value for
of the overall circuit (i.e. with source and
is
load applied).