Nihan Kosku Perkgözeem.eskisehir.edu.tr/nkperkgoz/EEM 321/duyuru/EEM321_01-Intro.pdfIntroduction to electronics SSI, "small-scale integration" (SSI), transistors numbering in the

Nihan Kosku Perkgöz

1. Microelectronics: Circuit Analysis and Design (Donald A. Neamen)

2. Microelectronic Circuits (Adel S. Sedra, Kenneth C. Smith)

Grading:

Midterm I: 25%

Midterm II: 25%

Final: 40%

HW & Quiz: 10%

Introduction to Electronics

Objectives• Understand the operation of circuit elements

(diodes & transistors)• Analyze and design circuits with nonlinear

elements, including diodes, BJTs and MOSFETs.• Analyze and design basic amplifier gain stages

and using MOSFETs and BJTs.CONTENT

pn junction (diode) physics

Diode circuits

BJTs (bipolar junction transistors)

FETs (field effect transistors)

Differential and multistage amplifiers

• Analog – continuous in time

• Analog design: compromise between speed, power consumption, resolution, supply voltage, linearity…

• Digital – discrete in time

• Digital design: compromise between power consumption and processing speed

• Design of amplifiers and filters

• ADCs

• Logic gates

• Receivers, transmitters

• Storage cells

Continuous Change Defined Levels

Introduction to electronics

Microelectronics: Small-scale electronic componentsmade from semiconductor.

Components: Transistors, capacitors, inductors,resistors, diodes…

Integrated circuit (IC): Electronic circuit manufacturedby lithography, or the patterned diffusion of traceelements into the surface of a thin substrate ofsemiconductor material.

Lithography: A process used in microfabrication toselectively remove parts of a thin film or the bulk of asubstrate.

Resistors, capacitors, inductors, diodes, transistors…


WHAT MAKES INTEGRATED CIRCUITS SO IMPORTANT???

COST & PERFORMANCE

Before ICs, there were vacuum tubes- discrete electronic components.Using semiconductor device fabrication techniques, the integration of large numbers oftiny transistors into a small chip became possible (First patent- 1949).• Mass production capability,• Reliability,• Building-block approach.


• The chips are printed as a unit by photolithography rather than being constructedone transistor at a time.

Photolithography selectively removes parts of a thin film or the bulk of a substrate.

It uses light to transfer a geometric pattern from a photomask to a light-sensitive "resist" on the substrate.

http://www.cnf.cornell.edu/cnf_process_photo_resists.html


• The components switch quickly and consume little power (compared to theirdiscrete counterparts) as a result of the small size and close proximity of thecomponents.

• As of 2016, the largest transistor count in a commercially available single-chipprocessor is over 7.2 billion—the Intel Broadwell-EP Xeon.

– Note: 15.8 million transistors per mm2!

First integrated circuit: Created by Jack Kilby(Texas Instruments) in 1958. It contains a singletransistor and supporting components.Kilby won the 2000 Nobel Prize in Physics forhis part of the invention of the integratedcircuit.

http://en.wikipedia.org/wiki/Integrated_circuit

//upload.wikimedia.org/wikipedia/en/4/42/Kilby_solid_circuit.jpg


SSI, "small-scale integration" (SSI), transistors numbering in the tens (a few logic gates).

MSI, "medium-scale integration", the next step in the development of integrated circuits, in the late1960s, introduced devices which contained hundreds of transistors on each chip.

LSI, "large-scale integration" In the mid 1970s, with tens of thousands of transistors per chip such as 1K-bit RAMs, calculator chips, and the first microprocessors…

VLSI, "very-large-scale integration", starting in the 1980s and continuing through the present.

ULSI, for "ultra-large-scale integration" was proposed for chips of complexity of more than 1 milliontransistors. A system-on-a-chip (SoC or SOC) is an integrated circuit.


Microelectronics is the keystone of the technological revolutions for

• Computers

• Communications

• Consumer electronics

Ex: Cellular Technology → Microelectronics exist in black boxes that process the received and transmitted voice signals.

Computer revolution

Raymond Kurzweil titled “The Age of Spiritual Machines”


Low power electronics enabling a variety of portable devices.

In last 20 years, communication bandwidth through a single optical fiber has increased by tenthousand fold.

Raymond Kurzweil titled “The Age of Spiritual Machines”


http://www.tue.nl/universiteit/faculteiten/faculteit-werktuigbouwkunde/onderzoek/research-groups/mechanics-of-materials/research/list-of-projects/3d-microelectronic-devices/

If we take the cover off a modern microprocessor, what do we see? We basically see two things. One is a thick web of metallic interconnects. The second thing is a high density of very small transistors.

The number of levels of interconnect technology is reaching now 7 among the leading companies

The picture on the right shows a cross section across the interconnect layer. It shows one level of local interconnect followed by six levels of Cu-based interconnects. They are all perfectly flat.


Moore's law : The number of transistors on integrated circuits doubles approximately every two years.

Benefits of increasing transistor integration:• System performance • Cost per function• Power per function• System reliability


Explain why scaling down is good.

What are factors limiting continued scalingin CMOS?


Basic Concepts and DefinitionsElectric Current and Ampere, Voltage (Potential Difference) Power and Energy, Active and Passive Devices

Analysis of CircuitsOhm’s Law, Nodes, Branches, Loops and Meshes, Kirchhoff’s Current Law (KCL)Kirchhoff’s Voltage Law (KVL)Voltage Division and Current Division Expressions

Nodal and Mesh Equations - Circuit TheoremsThevenin’s TheoremNorton’s TheoremMaximum Power Transfer Theorem Superposition Principle

Inductance and Capacitance

Operational Amplifiers

What is an operational amplifier? This particular formof amplifier had the name “Operational” attached to itmany years ago.

As early as 1952, Philbrick Operational Amplifiers(marketed by George A. Philbrick) were constructedwith vacuum tubes and were used in analogcomputers.* Even as late as 1965, vacuum tubeoperational amplifiers were still in use and cost in therange of $75.

* Some reports say that Loebe Julie actually developed the operational amplifier circuitry.

The Operational Amplifier

• Usually Called Op Amps

• An amplifier is a device that accepts a varying input signal and produces

a similar output signal with a larger amplitude.

• Usually connected so part of the output is fed back to the input.

(Feedback Loop)

• Most Op Amps behave like voltage amplifiers. They take an input

voltage and output a scaled version.

• They are the basic components used to build analog circuits.

• The name “operational amplifier” comes from the fact that they were

originally used to perform mathematical operations such as integration

and differentiation.

• Integrated circuit fabrication techniques have made high-performance

operational amplifiers very inexpensive in comparison to older discrete

devices.


The Philbrick Operational Amplifier.

From “Operational Amplifier”, by Tony van Roon: http://www.uoguelph.ca/~antoon/gadgets/741/741.html


Most probably, “operational” was used as a descriptorearly-on because this form of amplifier can performoperations of

• adding signals

• subtracting signals

• integrating signals, dttx )(

The applications of operational amplifiers ( shortenedto op amp ) have grown beyond those listed above.

Ideal Operational Amplifier

• Ideal op-amp is characterized by: Infinite input impedance

Infinite gain for differential input

Zero output impedance

Infinite frequency bandwidth


•V+: non-inverting input

•V−: inverting input

•Vout: output

•VS+: positive power supply

•VS−: negative power supply

Operational amplifier (Op-amp) is made of many transistors, diodes, resistors and capacitors in integrated circuit technology.

Ideal Operational Amplifier

• Equivalent circuit of the ideal op-amp can be modeled by:

Voltage controlled source with very large gain AOL

• known as open loop gain

Feedback reduces the gain of op-amp

Ideal op-amp has no nonlinear distortions

Analysis Method :

Two ideal Op-Amp Properties:

(1) The voltage between V+ and V is zero V+ = V

(2) The current into both V+ and V termainals is zero

For ideal Op-Amp circuit:

(1) Write the kirchhoff node equation at the noninverting terminal V+

(2) Write the kirchhoff node eqaution at the inverting terminal V

(3) Set V+ = V and solve for the desired closed-loop gain

Noninverting Amplifier

(1) Kirchhoff node equation at V+

yields,

(2) Kirchhoff node equation at V

yields,

(3) Setting V+ = V– yields

or

+Vin

Vo

RaRf

iVV

00

f

o

a R

VV

R

V

0

f

oi

a

i

R

VV

R

V

a

f

i

o

R

R

V

V1

+

vi

Ra

vov-

v+

Rf

+

vi

Ra

vov-

v+

Rf

R2R1

+

vi

vov-

v+

Rf

+

vi

vov-

v+

Rf

R2R1

Noninverting amplifier Noninverting input with voltage divider

i

a

f

o vRR

R

R

Rv ))(1(

21

2

Voltage follower

io vv

i

a

f

o vR

Rv )1(

Less than unity gain

io vRR

Rv

21

2


yields,


yields,


0V

0_

f

o

a

in

R

VV

R

VV

a

f

in

o

R

R

V

V

Notice: The closed-loop gain Vo/Vin is dependent upon the ratio of two resistors, and is independent of the open-loop gain. This is caused by the use of feedback output voltage to subtract from the input voltage.

+

~

Rf

Ra

Vin

Vo

Multiple Inputs


yields,


yields,


0V

0_

c

c

b

b

a

a

f

o

R

VV

R

VV

R

VV

R

VV

c

aj j

j

f

c

c

b

b

a

afo

R

VR

R

V

R

V

R

VRV

+

Rf

Va

Vo

Rb

Ra

RcVb

Vc

Inverting Integrator

Now replace resistors Ra and Rf by complex components Za and Zf, respectively, therefore

Supposing(i) The feedback component is a capacitor C,

i.e.,

(ii) The input component is a resistor R, Za = RTherefore, the closed-loop gain (Vo/Vin) become:

where

in

a

f

o VZ

ZV

CjZ f

1

dttvRC

tv io )(1

)(

tj

ii eVtv )(

+

~

Zf

Za

Vin

Vo

+

~

R

Vin

Vo

C

Op-amp are almost always used with a negative feedback: Part of the output signal is returned to the input with

negative sign Feedback reduces the gain of op-amp Since op-amp has large gain even small input produces large

output, thus for the limited output voltage (less than VCC) the input voltage vx must be very small.

Practically we set vx to zero when analyzing the op-amp circuits.

Inverting Amplifier

with vx =0 i1 = vin /R1

i2 = i1 and

vo = -i2 R2 = -vin R2 /R1

soAv=vo /vin =-R2 /R1

i1

i2

Inverting Amplifier

Since vo = -i2 R2 = -vin R2 /R1

Then we see that the output voltage does not depend on the load resistance and behaves as voltage source.Thus the output impedance of the inverting amplifier is zero.The input impedance is R1 as Zin=vin/i1=R1

Inverting Amplifier with higher gain

Inverting amplifier gain vo = -i2 R2 = -vin R2 /R1

Is limited due to fact that it is hard to obtain large resistance ratio.

Higher gains can be obtained in the circuit below where we have:i1=vin/R1=i2

from KCL at N2 we have: i2 + i3= i4

N2


Higher gains can be obtained in the circuit below where we have:i1=vin/R1=i2 from KCL at N2 we have: i2 + i3= i4

Also from KVL1: –vo=i2R2+i4R4 => i4=(-vo-i2R2)/R4

and from KVL2: i2R2=i3R3 => i3=i2R2/R3

KVL1

KVL2


Finally using: i2 + i3= i4 andi4=(-vo-i2R2)/R4

i3=i2R2/R3

we havei2+i2R2/R3 =(-vo-i2R2)/R4 => i2(1+R2/R3 +R2/R4)= -vo/R4


i2(1+R2/R3 +R2/R4)= -vo/R4

Substitutei2=vin/R1 => vin/R1 *(1+R2/R3 +R2/R4)= -vo/R4

to get the voltage gainvo/vin=-R4/R1 *(1+R2/R3 +R2/R4)


So if we chose R1=R3=1kW and R2=R4=10 kW then the voltage gain isAv=vo/vin==-R4/R1 *(1+R2/R3 +R2/R4)==-10*(1+10+1)==-120

Voltage Follower

=>

vo = v1(1+ R2 /R1)

vo = v1

Special case of noninverting amplifier is a voltage follower

so when R2=0

Since in the noninverting amplifier

Documents

Nihan Kosku Perkgözeem.eskisehir.edu.tr/nkperkgoz/EEM 321/duyuru/EEM321_01-Intro.pdfIntroduction to electronics SSI, "small-scale integration" (SSI), transistors numbering in the