Exam 1
ECE 4530
Prof. Apsel Fall 2014
Instructions: Please read all questions thoroughly before
providing answers. Answer all questions on the paper provided.
Box your final answers, and dont forget to write your name on all
pages. For all questions you m
Lectures 1012
Biasing, a little on variation,
passive current mirrors
1
10/12/2016
ECE 4530, Prof Alyosha Molnar,Cornell University
Biasing and Process Variation
(take 1)
For a given parameter,
every component changes
the same way.
Example numbers:
If
Lecture 21,22
Loading between circuits in FB
Phase and Gain Margin
Compensation
11/13/2016
ECE 4530, Cornell Univ. Prof.
Molnar
1
FB in real Opamp circuits
+
Vin
ZoutA Vout
ZinA

VFB
Av
+
Av
ZinB
Bv

ZoutB
Model both Feedforward
and feedback with rea
Lectures 23, 24
noise
11/17/2016
ECE 4530, Prof. Molnar, Cornell Univ.
1
Gaussian white noise
Most common form of noise:
White:
Voltage (or current) at each time
point is independent of each other v*(t)
point
Spectrum shows constant
magnitude across fre
ECE 4530 Homework Assignment 1 (review): Due September 4
Reminder: you must cite any other students you worked with (for instance, this
assignment reflects a collaboration with Prof. Molnar). Late homework will be marked
down 30%, and will not be accepted
Homework3
ECE 4530
Due Oct 1.
The goal of this homework is to go through the design of a simple amplifier, similar to
what would be needed to drive a highbandwidth signal off chip onto a transmission line.
You will verify your results in Lab 2b.
Your spe
ECE 453 Homework Assignment 5
Due Oct. 30
Topics: OpAmps
Active Current Mirrors
A
B
A
Figure 1 Intersil Low Power CMOS Operational Amplifier
The figure above shows a diagram from a data sheet for a commercial low power Operation Amplifier.
*Note that QN
ECE 4530 Integrated Circuit Design
Lab #2a Analysis of SingleStage Amplifiers
Date: Week beginning Sept 21, 2014.
Report due: October 13 at 5pm, along with part b.
Objectives:
1. Get experience with Cadence simulation environment
2. Learn to analyze simu
Exam 2
ECE 4530
Prof. Apsel Fall 2014
Instructions: Please read all questions thoroughly before
providing answers. Answer all questions on the paper provided.
Box your final answers, and dont forget to write your name on all
pages. For all questions you m
Lecture 1718
Increased Range OpAmps:
Mirrored, Folded Cascode
Inverters as Opamps
Differential OpAmps, CMFB
11/9/2016
ECE 4530, Cornell Univ. Prof.
Molnar
1
Problem with telescopic
VDD
M3
Vcascp
M4
g
M6
f
M5
Vout
Ibias
e
Vcascn
M7
M8
c
Vin
x1
M1
a
M9
Lectures 23, 24
noise
11/25/2016
ECE 4530, Prof. Molnar, Cornell Univ.
1
Gaussian white noise
Most common form of noise:
White:
Voltage (or current) at each time
point is independent of each other v*(t)
point
Spectrum shows constant
magnitude across fre
Lecture 1920
Feedback
11/9/2016
ECE 4530, Cornell Univ., Prof.
Molnar
1
General Feedback Formulation
+

f
y
A(s)
B(s)
+
A

u
e
R1
RF
11/9/2016
Input is u
Output is y
e = uf
y = A(s)e
f = B(s)y
y = A(s)e
=A(s)[uf]
=A(s)[uB(s)y]
y = A(s)uA(s)B(s)y
4530, Lecture 2
Review: a little more Bode,
Amplifiers, Opamps
1
1/23/2013
ECE 4530, Cornell University, Prof. Alyosha Molnar
How to make a flat 4pole filter
2 real poles (at =
2100krad/s)
2 complex:
20
Q=0.5
10
Q=8
0
Q=1.8
10
n = 2*100kHz
dB
20
3
4530, Lecture 3+4
Summary
1
9/5/2016
ECE 4530, Cornell University, Prof. Alyosha Molnar
PN junctions
Silicon is either doped to be:
ntype (more electrons than holes)
or
ptype (more holes than electrons)
When adjacent these form an insulating depletio
Lectures 13
Active current mirrors
Start Opamps
10/12/2016
ECE 4530, Prof. Alyosha Molnar, Cornell Univ.
1
VDD
RL
Ibias
RL
Vout
Vin+
x1
M1
Vin
x1
Vc
M2
Ibias
=
M3i
in
Using Current
mirrors as biases
robias
Cbias
M4
This implies Vc>VOD4
In general need
4530, Lecture 5
Summary
9/10/2016
ECE 4530, Cornell University Prof Alyosha Molnar
1
Subthreshold and velocity
Saturation
For VGS<VTH+100mV
For short channels, large
VGS, VDS
Square law breaks down
For VGS<VTH100mV
Exponential:
=
=
Square
law
ID
S
Lectures 14+15
Opamp specs,
Telescopic, 2stage
10/21/2016
ECE 4530, Prof. Molnar, Cornell
University
1
key specs for an opamp (not in
any order)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
DC Gain
Small signal output drive (Rout)
CMRR
PSRR
Z
Lecture 6
Alyosha Molnar
9/10/2016
ECE 4530, Cornell University Prof Alyosha Molnar
1
Source Follower (common Drain)
If bulk grounded:
VDD
gm
A
g m g mb
Vin
Vout
Z out
RL
1
g m g mb
vin
gmb
g m g mb
R
L
0.9
1
ro
1
g m g mb
1
ro
1.1
gm
ro
gm
gm
R
1
L
Lecture 9 summary
Manufacturing, layout
10/12/2016
ECE 4530, Prof. Molnar Cornell U
1
How to manufacture an NFET*
PR
p Si
mask
PhotoLithography
add photoresist
Expose through mask:
miniaturizes what drawn in mask
Dissolve exposed PR (or
unexposed, d
Lecture 16
Analyzing big nasty circuits
10/21/2016
ECE 4530, Prof. Alyosha Molnar,
Cornell Univ
1
An aside: what to ignore?
Complex circuit
analysis is mostly
about intelligently
ignoring things in
small signal
analysis
Only pay attention
to what you ha
Lecture 26
Nonlinearity: piecewise linear,
power series
General problem
So far have tackled
nonlinearity as a
limitation on signal
magnitude
Input range
Output range
Can approximate
with piecewise linear
Issues with this:
No good for soft
nonlineari