Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #10
1. Based on the concept of half-circuit, the output impedance Rout is
Rout = [1 + gm3 (r3 |R1 )]rO3 + r3 |R1 , where R1 = 1 + gm1 r1 |
RS
2
+ r
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #9
1. The voltage at node P is
VP = VCC (I1 + I2 )R1 = VCC 2I0 R1
The peak-to-peak swing of VP is 0 and the common-mode level of VP is VCC 2I0 R1 .
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #8
1. Let IB be the base current goes through the resistor RP , we have
I1
IREF I1
IB = IB IB =
.
( + 1)
IREF
Next,
IS exp
VB
VB IB RP
I1
= I1 ,
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #7
1. (a) Since Rp is in parallel connection with r1 , we have
Rout = [1 + gm1 (r1 |RP |rO2 )]rO1 + (r1 |RP |rO2 ).
(b) Since Rp is in parallel con
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #5
1. To nd the closed-loop gain, we consider the equivalent circuit shown in Figure 1(a). By KCL, we have
Vin VX
A0 V1 VX
VX
+
=
VX =
Rin
R1
R2
T
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #4
1. The input impedance Rin is given by
Rin =
1
1
1
.
50 =
gm1 =
gm1
gm1
50
The output impedance is Rout = RD = 500 . Since M1 must operate in
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #3
1. Since ID1 is 0.5 mA, assume M1 operates in the saturation region, we have
ID1 =
1
W
1
20
n Cox (VGS VT H )2 0.5 103 = 200 106
(VGS 0.4)2 VG
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #2
1. (a) VGS = 1 V and VDS = VDD ID RD . We assume M1 operates in the saturation region, the drain
current is given by
ID =
W
1
W
1
n Cox (VGS VT
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Solution to Homework #1
1. This combination can be treated as a series connection of two resistors. The width and length of Meq are
Leq = 2L and Weq = W .
2. Since the
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #10
1. Calculate the voltage gain of the degenerated pair depicted in Figure 1. VA < . (Hint: Av = Gm Rout .)
Figure 1
2. A student has mistakenly used pnp cas
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #9
1. In the circuit of Figure 1, I1 = I0 cos wt + I0 and I2 = I0 cos wt + I0 . Plot the waveforms at X, Y , and
P . Determine their peak-to-peak swings and co
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #8
1. Due to a manufacturing error, resistor Rp has appeared in series with the base of QREF in Figure 1. If
I1 is 10% greater than its nominal value, express
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #7
1. Due to a unexpected manufacturing error, a parasitic resistor Rp has appeared in the cascode circuits
shown in Figure 1. Determine the output resistance
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #6
1. Consider the precision rectier depicted in Figure 1(a), where a parasitic resistor RP has appeared in
parallel with D1 .
(a) Express VX and VY as functio
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #5
1. A noninverting amplier incorporates an op amp having an input impedance of Rin . Modeling the op
amp as shown in Figure 1, determine the closed-loop gain
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #4
In the following problems, unless otherwise stated, assume n Cox = 200A/V2 , p Cox = 100A/V2 , = 0,
and VT H = 0.4 V for NMOS devices and -0.4 V for PMOS de
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #3
In the following problems, unless otherwise stated, assume n Cox = 200A/V2 , p Cox = 100A/V2 , = 0,
and VT H = 0.4 V for NMOS devices and -0.4 V for PMOS de
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #2
In the following problems, unless otherwise stated, assume n Cox = 200A/V2 , p Cox = 100A/V2 , and
VT H = 0.4 V for NMOS devices and -0.4 V for PMOS devices
Department of Electrical Engineering, Tamkang University
Microelectronics, Summer 2008
Homework #1
In the following problems, unless otherwise stated, assume n Cox = 200A/V2 , p Cox = 100A/V2 , and
VT H = 0.4 V for NMOS devices and -0.4 V for PMOS devices