PSZ 19:16 (Pind. 1/07)
UNIVERSITI TEKNOLOGI MALAYSIA
DECLARATION OF THESIS / UNDERGRADUATE PROJECT PAPER AND COPYRIGHT
Author’s full name :
Date of birth
:
Title
:
ABDULLAH ALI ABDULLAH AJLAN
1 JANUARY, 1988
DEVELOPMENT OF RF NON-THERMAL PLASMA
SOURCE FOR MELANOMA TREATMENT
Academic Session:
2012 / 2013
I declare that this thesis is classified as :
√
CONFIDENTIAL
(Contains confidential information under the Official Secret
Act 1972)*
RESTRICTED
(Contains restricted information as specified by the
OPEN ACCESS
I agree that my thesis to be published as online open access
(full text)
I acknowledged that Universiti Teknologi Malaysia reserves the right as follows :
1. The thesis is the property of Universiti Teknologi Malaysia.
2. The Library of Universiti Teknologi Malaysia has the right to make copies for the purpose
of research only.
3. The Library has the right to make copies of the thesis for academic exchange.
Certified by :
SIGNATURE
SIGNATURE OF SUPERVISOR
04160453
ASSOC. PROF. DR. ZOLKAFLE BUNTAT
(NEW IC NO. /PASSPORT NO.)
Date : 24 June 2013
NOTES :
*
NAME OF SUPERVISOR
Date : 24 June 2013
If the thesis is CONFIDENTIAL or RESTRICTED, please attach with the letter from
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“I hereby declared that I have read this thesis and in my
opinion this thesis is sufficient in terms of scope and quality for the
award of Bachelor of Engineering (Electrical).”
Signature
: ………………………………………………
Name of Supervisor
: ASSOC. PROF. DR. ZOLKAFLE BUNTAT
Date
: 24 JUNE 2013
DEVELOPMENT OF RF NON-THERMAL PLASMA SOURCE FOR
MELANOMA TREATMENT
ABDULLAH ALI ABDULLAH AJAN
A project report submitted in partial fulfilment of the
requirements for the award of the degree of
Bachelor of Engineering (Electrical)
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
JUNE 2013
ii
I declare that this thesis entitled “Development of RF Non-Thermal Plasma Source
for Melanoma Treatment” is the result of my own research except as cited in the
references. The thesis has not been accepted for any degree and is not concurrently
submitted in candidature of any other degree.
Signature: ..............................................
Name
: ABDULLAH ALI ABDULLAH AJLAN
Date
: 24 JUNE 2013
iii
To the Almighty Allah, for giving me guidance and blessings.
To my beloved parents for their unconditional love and unlimited support,
To my darling wife and my beloved daughter.
iv
ACKNOWLEDGMENT
First and foremost, all gratitude to the omnipresent Allah for giving me the strength
through my prayers and to plod me on despite the difficult situations I passed
through till my graduation.
I would like to express my gratitude towards my supervisor Assoc. Prof. Dr. Zolkafle
Buntat, for his cooperation, guidance, inspiration, and valuable advices while doing
this project. Also, I would like to thank Faculty of Electrical Engineering, University
Technology Malaysia for the continuous care and support.
In addition, an honourable mention goes to my dear friends Omar Khalaf and Sharif
Abdulkareem. I cannot say thank you enough for their tremendous support,
motivation and help. I will really miss the beauty of the time we spent.
I would like to express my love and gratitude to my beloved wife; for her
understanding, patience, support & endless love, through the duration of my study.
Finally, yet importantly, I would like to express my heartfelt thanks to my beloved
parents for their blessings, my friends/classmates for their help and wishes for the
successful completion of this project.
v
ABSTRACT
Non-thermal plasma has been an attractive research topic in the plasma
physics due to its great ability to interact with living tissue, cell and micro-organism
without affecting nearby cells. Great work have been reported to generate Nonthermal plasma under atmospheric pressure. In practical life, there are various
applications for the non-thermal plasma such as dental cavity, mammalian vascular
cell treatment and cancer treatment. This research generally discusses about the
treatment of skin cancer via non-thermal plasma. However, the scope of research is
to develop an affordable, portable and efficient radio-frequency power supply
suitable for generating non-thermal plasma that could be used special for skin cancer
treatment. Development of such system will be done based on modified E-class
amplifier along with the concept of resonance circuit. The proposed designed system
will be simulated using MATLAB/Simulink and MULTISIM to verify the system
performance. Besides, hardware development comprises of function generator of IC
SG3525 with frequency range (300 KHz – 1MHz) and Power MOSFET driver
TC4427 to drive the MOSFET switching process. MOSFET IR540N is acting as
high frequency power switch on the E-class amplifier circuit. According to the
results obtained from both simulation and hardware development, the proposed
system output voltage signal is a sine waveform with an amplitude of 375 Vpp and
corresponding frequency range of (300 KHz – 910 KHz). The results prove that
output voltage is able to produce non-thermal plasma. The proposed topology has
been verified with successful results obtained.
vi
ABSTRAK
Plasma bukan-termal (panas) telah menjadi topik penyelidikan yang menarik
dalam fizik plasma kerana kemampuannya yang besar untuk berinteraksi dengan tisu
hidup, sel dan mikro-organisma tanpa menjejaskan sel-sel berdekatan. Kerja besar
telah dilaporkan untuk menjana plasma bukan-termal di bawah tekanan atmosfera.
Dalam kehidupan praktikal, terdapat pelbagai aplikasi untuk plasma bukan-termal
seperti rongga pergigian, rawatan sel vaskular mamalia dan rawatan kanser. Kajian
ini secara umumnya membincangkan tentang rawatan kanser kulit melalui plasma
bukan-termal.
Walau
bagaimanapun,
skop
penyelidikan
adalah
untuk
membangunkan sumber bekalan berfrekuensi radio pada harga berpatutan, mudah
alih dan cekap yang sesuai untuk menjana plasma bukan-terma yang boleh
digunakan khas untuk rawatan kanser kulit. Pembangunan sistem itu akan dilakukan
berdasarkan pengubahsuaian penguat E-kelas bersama-sama dengan konsep litar
resonans. Cadangan sistem yang direka akan disimulasi menggunakan MATLAB /
Simulink dan MULTISIM untuk mengesahkan prestasi sistem. Selain itu,
pembangunan perkakasan terdiri daripada penjana fungsi IC SG3525 dengan julat
frekuensi (300 KHz - 1MHz) dan Kuasa pemandu MOSFET TC4427 untuk
memandu MOSFET proses pensuisan. IR540N MOSFET bertindak sebagai suis
kuasa berfrekuensi tinggi pada litar penguat E-kelas. Menurut keputusan yang
diperolehi daripada kedua-dua simulasi dan pembangunan perkakasan, sistem yang
dicadangkan menghasilkan isyarat voltan bentuk gelombang sinus dengan amplitud
375 Vpp dan julat frekuensi sama (300 KHz - 910 KHz) pada keluaran. Keputusan
membuktikan bahawa voltan keluaran dapat menghasilkan plasma bukan- termal.
Topologi dicadangkan itu telah disahkan dengan keputusan yang berjaya diperolehi.
vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xi
LIST OF FIGURES
xii
LIST OF ABBREVIATIONS
xiv
LIST OF SYMBOLS
xv
LIST OF APPENDICES
xvi
INTRODUCTION
1
1.1
Background of Study
1
1.2
Problem Statement
3
1.3
Objectives of the Study
4
1.4
Scope of the Study
5
LITERATURE REVIEW
6
2.1
Introduction
6
2.2
Generating Plasma
6
2.3
Melanoma Cancer
9
2.4
Non-thermal Plasma for Skin Cancer Treatment
9
2.4.1 Fundamental Principle
10
Non-thermal Plasma Setup for Skin Cancer Treatment
12
2.5
viii
2.6
Metal Oxide Semiconductor Field Effect Transistor
15
2.6.1 The Process of MOSFET Turn On
16
Modified E-class Amplifier
18
RESEARCH METHODOLOGY
23
3.1
Introduction
23
3.2
Methodology Procedure
24
3.3
Related Strategies
25
3.4
Modelling Software
25
3.4.1 MATLAB/Simulink R2012a
25
Hardware Development
26
2.7
3
3.5
4
5
RADIO FREQUENCY POWER SUPPLY DESIGN
28
4.1
Introduction
28
4.2
Simulation Development
30
4.3
Proposed E-Class Amplifier Simulation
32
4.4
Development of Hardware
33
4.4.1 Square Wave Function Generator
33
4.4.2 Power MOSFET Driver
36
4.4.3 Entire Modified E-Class Amplifier
39
RESULTS AND DISCUSSION
40
5.1
Introduction
40
5.2
Simulation Results of Simulink
41
5.3
Simulation Results of MULTISIM
44
5.4
Hardware Implementation Results
46
5.4.1 Function Generator Output
46
5.4.2 Power MOSFET Driver Output
47
5.4.3 Complete E-Class Amplifier
48
ix
6
CONCLUSION AND RECOMMENDATIONS
50
6.1
Conclusion
51
6.2
Recommendations
51
REFERENCES
46
APPENDICES
56
APPENDIX A
56
x
LIST OF TABLES
TABLE NO.
1.1
TITLE
Scope of the Project
PAGE
5
xi
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Thermal Plasma Application
2
2.1
Configurations of Non-Thermal Plasma Applications
8
2.2
Configuration of RF Capacitively Coupled Discharge
8
2.3
Procedure of Apoptosis in Mammalian Cells
11
2.4
Results for Melanoma treatment using plasma
11
2.5
Non-thermal Plasma Setup
13
2.6
Stability Curves of the Plasma
14
2.7
Symbol and equivalent circuit of a MOSFET
15
2.8
Transfer Characteristics for a Power MOSFET
16
2.9
A MOSFET being turned on by a driver in a
clamped inductive load
2.10
17
A MOSFET being turned off by a driver in a
clamped inductive load
17
2.11
Modified Class E Amplifier Circuit Diagram
18
2.12
Experimental and Numerically simulated waveforms
of output voltage vs. output current
21
xii
2.13
Output voltage maximal gain response surface
as a function of CR and R.
21
2.14
Discharge power as function of Reactor Gap
22
3.1
Procedure Flow Chart
23
4.1
Modified Class E Amplifier Simulation Circuit using
30
4.2
Block Diagram of SG3525 Waveform generator
33
4.3
Pin connection of SG3525 Waveform generator
34
4.4
Relationship between RT, CT and frequency for SG3525
35
4.5
SG3525 Hardware implementation
36
4.6
TC4427 MOSFET driver block diagram
36
4.7
TC4427 MOSFET driver connection circuit
37
4.8
Relationship between Capacitor Load and supply current
38
4.9
TC4427 Hardware connection
38
5.1
Function generator waveform
41
5.2
Output Current waveform
42
5.3
Simulated waveform of Vc and Vo
44
5.4
Simulated waveform of VO
45
5.5
Simulated waveform of VO
46
5.6
Output waveform of SG3525
47
5.7
Output waveform of TC4427
47
5.8
Output waveform of overall circuit
48
xiii
LIST OF ABBREVIATIONS
RF
-
Radio Frequency
F
-
Frequency
BNC
-
Bayonet Neill–Concelman
DC
-
Direct Current
AC
-
Alternating Current
UTM
-
Universiti Teknologi Malaysia
CCP
-
Capacitvely Coupled Plasma
NI
-
National Instrument
OD
-
Outer Diameter
ID
-
Internal Diameter
IGBT
-
Insulated Gate Bipolar Transistor
MOSFET
-
Metal–oxide–semiconductor Field-effect Transistor
IC
-
Integrated Circuit
PCB
-
Printed Circuit Board
xiv
LIST OF SYMBOLS
K
-
Kelvin
Cᴼ
-
Degree Celcius
UV
-
Ultraviolet
Min
-
Minute
ns
-
Nanoseconds
IG
-
Gate Current
ID
-
Drain Current
IS
-
Source Current
V
-
Volts
kV
-
Kilo Volts
kΩ
-
Kilo Ohms
mm
-
Milimeter
cm
-
Centimetre
mV
-
Mili Volts
mW
-
Mili Watts
GHz
-
Giga Hertz
MHz
-
Mega Hertz
Vpp
-
Peak-to-peak Voltage
Vp
-
Peak Voltage
He
-
Helium
uH
-
Micro Henries
mH
-
Mili Henries
ZL
-
Load Impedance
VGS(th)
-
Threshold Voltage
VCC
-
Power Supply Voltage
xv
LIST OF APPENDICES
APPENDIX
A
TITLE
PAGE
Components Datasheets
56
CHAPTER 1
INTRODUCTION
1.1
Background of Study
In common, there are three states of matter which are solid, liquid and gas.
Human-beings are very well known with these three states as they are facing them in
daily life.
In 1879, an English physicist, Sir William Crooker first discovered the forth
state of matter which is so-called plasma. It is, then, being employed for much
development by DR. Irving Langmuir, who was an American chemist and physicist
in 1929 [5].
In physic science, plasma could be defined as conductive assemblies of
charged particles, neutrals as well as field radicals that demonstrate cumulative
effects, which have similar elements with gases. Because of the considerable amount
of charge carries which tends to make the plasma electrically conductive, so that the
plasma responds much highly to electromagnetic fields.
Generally, plasma is generated when high energy, such as ultraviolet light,
which ionizes the atoms and particles, that in turn triggers gas to be electrically
2
conductive. The produced conductive gas is what-called plasma. Typically the
temperatures associated with plasma electrons is usually generally over
although the actual temperature range with regard to neutrals as well as ions rely
upon type associated with plasma and may vary through room temperature to
.
Based on their relative temperature of charge carriers, molecules and ions,
there are two types of plasma, which are well-known as “thermal” and “non-thermal”
plasma. For thermal plasma, plasma is considered to be at equilibrium because its
components, the molecules and particle charges, are in thermodynamics steady-state.
In other words, the temperature range of free electrons is the identical with the
temperature range of molecules, other charge particles. Thermal plasma may range of
high temperature up to
, therefore several applications of thermal could be
found in practical associated with high temperature, such as metal spraying and
thermal plasma cutting, as shown in figure 1.1 below.
(a)
(b)
Figure 1.1: Thermal Plasma Applications (a) metal spraying [22], (b) thermal plasma
cutting [22]
On the other hand, as for non-thermal plasma free electrons temperature and
the gas molecules, ions and atom are not in equilibrium with each other. Typical
temperature range of gas molecules, ions and atom are significantly lesser (20° - 25°)
than temperature of free electrons. Essentially, the non-thermal plasma has no major
thermal effect or damage to close by items as it possess low temperature range.
Therefore, non-thermal plasma has many application for medical purposes in real-life
compared to the thermal plasma.
3
The most recent development considerably more emphasizes on utilizing the
non-thermal plasma in application associated with biomedical and treating living
tissues on human body. The non-thermal plasma has got functionality of bacterial
deactivation, non-inflammatory cell modification and healing effect on living
organism. All these abilities managed to increase number of applications concerns
the interaction between non-thermal plasma and biological tissues. Examples of
such applications are plasma needle, plasma jet and DBD plasma.
1.2
Problem Statement
Non-thermal plasmas have got quite a lot of focus within the last few years
for their significant exposure in different scientific areas. Various applications of
non-thermal plasma can be found in reality such as dental cavity, treatment of
mammalian vascular cells and melanoma cancer treatment.
Melanoma treatment technique involves surgery elimination of tumour,
adjuvant treatment, chemo- and immunotherapy, or radiation therapy. Each one of
these ways of melanoma treating possesses some severe as well as uncomfortable
negative effects. The chemo-therapy causes hair diminishing, tiredness, anemia, and
being much susceptible to illness [23]. The radiation furthermore causes tiredness,
loss in urge for food, elevated level regarding attacks. Additionally, these kinds of
therapy strategies can be very expensive and require certain products and drugs [23].
Considering these types of possible problems associated with conventional
ways of malignancy treatment, some researchers has initiated an investigation to
develop non thermal plasma as affordable, convenient, new scientific tool for a wide
range of medical applications [22].
4
Non-thermal has capability to destroy the tumour by inducing apoptosis in
malignant cell. Further, non-thermal plasma treatment of skin cancer (malignancy)
does not have side effect since the plasma is high precision with sharp line that treat
the affected part only without damaging surrounding cells [8].
The actual plasma system source which experts is utilizing currently could be
very costly. The reason behind is that usage of commercialized function generators
and research amplifier in generating non-thermal plasma at radio frequencies.
Therefore, in this project efforts had been made to develop an affordable RadioFrequency power supply for generating non-thermal plasma to be used for skin
cancer treatment [10].
1.3
Objectives
The major goal of this project is to study, design and develop of radio
frequency power source that could be used to generate non-thermal plasma for skin
cancer treatment. However, the goal will be achieved through three main objectives:
i.
To design a Radio-Frequency power supply for plasma cancer
treatment.
ii.
To conduct a simulation study using MATLAB to verify the designed
circuit.
iii.
To develop proposed plasma source suitable for skin cancer treatment.
5
1.4
Scope of the project
This project is mainly concerning with developing the radio frequency source
to generate non-thermal plasma by means of certain circuit topology. Simulation
study and modelling on the proposed RF circuit will be carried out, followed by deep
analysis of circuit performance. Table 1.1 demonstrates the scope of the research
project.
Table 1.1: Scope of the Project
Simulation Study
Circuit Development
Simulating the proposed circuit with
Develop the proposed circuit utilizing
MATLAB/Simulink software for
the breadboard.
verification.
Simulating the proposed circuit with
Test and examine the developed system
MULTISIM software for verification.
performance.
CHAPTER 2
LITERATURE REVIEW
2.1
Introduction
Throughout this section, some major principles, concepts and terminologies
of non-thermal plasma will be intensively studied and reviewed. This chapter
provides a deep exposure about the non-thermal plasma nature, types, application as
well as the radio-frequency source which would be suitable to be used to generate
non-thermal plasma. Besides, this chapter gives comprehensive theory on the skin
cancer therapy using non-thermal plasma.
2.2
Generating Plasma
In practice, there are several techniques used to generate plasma, however
one principle is common to all of them. Recently, the technique used to generate
plasma is the electric field breakdown concept, between two electrodes, inclosing
aneutral gas such as helium gas He [5]. Within the field, the fast charge carriers (free
7
electrons) usually convert their energy to plasma by colliding the gas atoms and
molecules. Free electrons conserves their power in elastic collision with other
particles because of small weight and they just convert their energy in inelastic
collisions with other particles.
Based on electric field breakdown technique, plasma might be categorized to
major types which are Direct Current discharge (DC), Pulsed dc discharge (PDC),
Radio Frequency discharge (RF) and microwave discharge [6].
The RF discharge is further classified to inductively coupled discharge and
capacitive coupled discharge. Both, inductive and capacitive coupled, have several
applications in the real life. Their applications mainly concern with interaction with
living tissue, species and relationship between them [6].
Dielectric Barrier Discharge (DBD), Local Plasma Jet and Remote Plasma Jet
are some popular applications for RF discharge [22]. DBD, which had been invented
by Ernst Werner von Siemens in 1857, is the electrical discharge occurred between
two electrodes splitted up by dielectric barrier. The barrier could be air or an inert
gas with lower voltage breakdown [22]. Helium is considered best to choose as
barrier due to its lower ionization breakdown. Both, the local and remote plasma jet,
could be furthermore divided into capacitively and inductively coupled sets. The
configuration of these types are show in figure 2.1 [22].
Compared with other types of plasma, the configuration of DBD application
is much easiest than the others, which consists of two conductors fixed to insulator.
The electric field has maximum value only at the surface of the insulator which leads
to maximum plasma density over this region. High energized and short lived
radical’s species present in the high plasma density region while the longer lived
radicals slowly float away from the surface. For best efficiency, the target surface
must be approximately close to the DBD high plasma density region during
decontamination.
8
The radio frequency discharge might be also subdivided to inductively and
Figure 2.1: Configurations of Non-Thermal Plasma applications
capacitively couple discharge. An important application for RF discharge is the
plasma needle. Plasma needle is utilizing capacitively coupled discharge technique to
produce plasma within its electrodes [6]. Basic construction of the RF capacitively
coupled plasma is shown in figure 2.2.
Figure 2.2: configuration of RF capacitively coupled discharge
9
2.3
Melanoma Cancer
Melanoma is a malignant tumour of melanocytes that could be recognized
mainly in skin, also in the bowel and the eye. It is the less common type of skin
cancer yet leads to the greater part of skin cancer associated deaths. Malignant
melanoma is a severe form of skin cancer. That is because of uncontrolled
development of colour cells, called melanocytes. In spite of several centuries of
concentrated laboratory and research, the only actual cure is surgical resection of the
primary tumour before it reaches a thickness bigger than 1 mm. Around 160,000 new
cases of melanoma are identified internationally each year, and it is further common
in males and Caucasians. It is more common in Caucasian populations living in
sunlit weathers than in other groups. According to a WHO report around 48,000
melanoma related deaths occur worldwide per year. Malignant melanoma accounts
for 75 percent of all deaths associated with skin cancer [23].
2.4
Non-Thermal Plasma for Skin cancer treatment
The cure for malignancy cancer includes medical elimination of the cancer
tumour, adjuvant treatment, chemo- and immunotherapy, or radiation therapy. All
these methods of treatment of melanoma skin cancer have some severe and offensive
side effects [23]. Chemotherapy causes hair loss, tiredness, anemia, disposed to
infection. Radiation also leads to fatigue, loss of appetite, and augmented rate of
infections. Additional these treatment modalities are expensive and need extensive
equipment and drugs.
In the look of these possible matters associated with old methods of cancer
treatment, A. J. Drexel Plasma Institute began an investigation to improve Nonthermal Plasma as a low cost, moveable, new clinical device for a wide range of
clinical applications. Non-thermal plasma can destroy microorganisms or tempt
apoptosis in malignant cells. It can be applied in sub-lethal doses to cause specific
10
biological effects, comprising gene transfection, cell detachment, wound healing, and
blood coagulation. Non-thermal plasma can although have choosy properties.
Recently, researches of plasma blood coagulation and bacteria deactivation, plasma
did not prove assessable deadliness in the nearby living tissue [23].
The operational standard of this plasma discharge is similar to the Dielectric
Barrier Discharge (DBD) presented by Siemens in 1859. DBD happens at
atmospheric pressure in air or other gases after high voltage of sinusoidal waveform
or short period pulses is being applied among two conductors, with a conductor
being insulated. The insulator avoids current build-up between the conductors,
generating electrically safe plasma deprived of substantial gas heating. This method
permits straight cure of melanoma skin cancer without the side effects detected after
chemo or radiation therapy or thermal damage witnessed in more traditional thermal
plasmas [23].
2.4.1
Fundamental principle
Capability associated with a cell to self-regulate is actually a crucial feature
in higher bacteria permitting for proper expansion, development, as well as death in
actual essential times [23]. Apoptosis, which is also called programmed cell death, is
certainly a significant component of the self-regulation [24]. The non-functioning of
a tumour-suppressor gene which assists apoptosis, or even the over expression of an
anti-apoptotic proteins are together vital path ways at cancer growth [24].
Numerous anti-cancer treatments usually are directed at modulating all these
aspects. Scientists are working with different bioactive agents at an effort to focus
on several elements associated with apoptotic path ways. Several of these methods
nevertheless still persist at the preclinical improvement minor to small effectiveness
and medicine fight [23]. The existing researches seek out to advance techniques to
control apoptotic movement at cancer cells by assessing an electro-chemical
11
methodology to prompt apoptosis. Non-thermal at atmospheric pressure dielectric
barrier discharge plasma could produce a new novel technique to initiation of
apoptosis [23].
Figure 2.3 shows the process of apoptosis in mammalian cells. As it can be
seen, when a normal cell has high amount of apoptosis, it starts to shrink in the first
stage. After shrinking from its original size, the cell membrane begins to bleb. While
blebbing continues, nuclear collapse occurred during this stage. Finally, apoptotic
body formation with some lysis of the apoptotic bodies.
Figure 2.3: Procedure of Apoptosis in Mammalian cells
Figure 2.4: Results for Melanoma Treatment using Plasma
12
Figure 2.4 above demonstrates results obtained from several examples of
triplicate (± S.D.). Trypan blue staining exposed that plasma usage at small power
for up to 5 seconds did not expressively rise the amount of dead cells directly
following treatment. Although, at upper values doses, the percentage dead cells
enlarged proportionally with dosage of plasma. Examination for cells being treated
for period of 15 seconds at very high power demonstrated an increased in apoptosis
at 24 and 48 hours post-treatment.
In short, plasma treatment prompts apoptosis in tumour cells over a path way
that seems like to stay reliant on creation of reactive oxygen species by plasma in
fluid. Meanwhile this plasma effect is non-thermal, this might be a choosy method
to cure cutaneous malignancies with no need of introducing inflammatory responses.
Non-thermal plasma is a convenient implement to create directed cell death without
inducing necrosis and inflammation.
2.5
Non-Thermal Plasma Setup for Skin Cancer Treatment
In early of year 2002, Physicist Eva Stoffels and her crew had discovered a
creative concept which is the non-thermal plasma construction. The plasma setup is a
new design of non-thermal plasma source that is being able to generate plasma at
atmospheric pressure utilizing idea of radio-frequency discharges. The setup consists
of a single electrode arrangement which operated thru the existence of helium gas
[5]. The plasma produced in this configuration functions at nearly room temperature
and at atmospheric pressure, which does not make any form of pain and major
damage of the tissue, however it permits treatment of rough surface and has got a
small saturation depth. All these capabilities enable this plasma setup configuration
to be applied in bio-medical applications.
13
Radio-Frequency plasma can be generated with high frequencies in range of
(300 KHz – 1 MHz) by using a waveform generator. Output of waveform generator
is then improved by an RF amplifier. After that, the signal is moved to a matching
network. The power is observed by using a power meter and Dual Directional
Coupler while the voltage is measured through Tektronics probe [22]. The basic
configuration of the plasma setup is shown in figure 2.5. The electrical
measurements show that plasma operates at quite low voltages from 200-500 Vpp
and the power losses range from 10 mW to at most a few watts [4].
Figure 2.5: Non-thermal Plasma Setup [7]
This particular plasma source can generate plasma that includes free electrons
and ions, various chemical reactive species and very high energy Ultra-Violet
photons [8]. The Ultra-Violet energy and density of organic reactive species are
important at identifying the overall performance of plasma at the treatment of
melanoma cancer. The bacterium inactivation with an atmospheric pressure
discharge could be mostly due to Ultra-Violet radiation. With the lack of UV
production, action of chemical reactive species such as O-, OH-, N2 +, N2 and He may
lead to micro-organism inactivation too. Therefore, the micro-organism inactivation
depending on the operating conditions, it can be achieved within main Ultra-Violet
radiation or in purely action of the reactive species [9].
14
The actual plasma generated with existence of gas helium are almost steady
as well as have got the broadest variety of operating circumstances. The operating
conditions associated with the non-thermal plasma as a function of helium flow rate
and percentage of air admixture at a constant total flow rate are shown in Figure 2.6
[22]. This is mostly important in order to preserve funds as well as suitability of
operation in small model openings. Subsequently, the existence of gas helium, the
plasma has very low power losses and the maintaining voltage is tolerable, it is
preferable to be used in biomedical applications.
Figure 2.6: Stability Curves of The Plasma: (a) as a function of helium flow rate
and (b) as a function of percentage of air admixture at a constant total flow rate
(350 ml min-1). Displayed are the breakdown voltages, needed to ignite the plasma
(●), minimum operating voltages, just above extinction threshold (■) and
maximum voltages, just below arcing (▲) [5].
15
2.6
Metal Oxide Semiconductor Field Effect Transistor (MOSFET)
Currently, MOSFET has become an important component in the power
electronics world. Nowadays, there are a lot of application utilizing MOSFET as
major part, and the number of applications is expected to increase dramatically.
MOSFETs, in general, have main two main operating regions, which are the
switching mode and amplifying mode. They can be easily switched at high
frequencies with no minority charge carriers. MOSFETs have a limiting ability in
switching which is influenced by two main factors: the actual transient time and the
period required for charging and discharging the input gate capacitance [20].
Figure 2.7: Symbol and equivalent circuit of a MOSFET
Figure 2.7 shows N-Channel MOSFET symbol as well as its corresponding
circuit of MOSFET model along with 3 junction capacitances, namely:
,
and
. Miller Capacitance which is the capacitance between the gate and drain
junction,
and it has big responsible in the switching speed of the internal
MOSFET [20]. Prior to drain current
flowing, capacitance
till a crucial point of the threshold voltage level
.
must be charged
16
Figure 2.8 demonstrates the graph of
characteristics of power MOSFET. It has a slope of
curve along with
⁄
of
where it is equal to
trans-conductance, gm. As for Power MOSFETs, it is suitable to put main
consideration the relation to be linear for values of
above
. The relation is
given by the following formula:
Figure 2.8: Transfer characteristics for a power MOSFET
2.6.1
The Process of MOSFET Turn On
The phenomena of MOSFET turn on is more important than turn off, so this
section provides discussion on the turning on the MOSFET. Figure 2.9 and figure
2.10 show process of turning on and off a power MOSFET by driving it in a clamped
inductance load. As stated before, in order to start the conduction mode the
capacitance
is needed to charge up to point of
. The inductance clamped
17
load is represented by Diode D which is connected anti-parallel along with the
inductor [20]. The internal gate resistance of MOSFET, which is also called intrinsic
resistance
. The junction capacitances (
connected at original way. The input DC voltage,
,
and
) are shown to be
being applied to the circuit
through connection of drain of MOSFET and the inductance clamped load.
At the output of the driver terminal, the output voltage is amplified with peak
value,
when positive pulse is entering the input terminal for the driver. The output
from Driver is connected directly to Gate of the MOSFET [20].
Figure 2.9: A MOSFET being turned on by a driver in a clamped inductive load
Figure 2.10: A MOSFET being turned off by a driver in a clamped inductive load
18
2.7
Modified E-class Amplifier
Currently, E-class amplifier has become very popular in the electronics world
related to the non-linear amplifier topologies. A sequence of varied studies,
enhancements, and adaptations on its typical topology has been conducted, targeted
at the production of radio frequency ac waveform [10]. E-class amplifier has been
known with high efficiency which is up to 85% comparing it with class B and class
C with 60% and 70% efficiency respectively. Naturally, class E amplifier has smaller
power losses by a factor of 2.3 as compared to conventional class B and class C
amplifier with same transistor at same frequency and output power [13]. Figure 2.11
shows the circuit of modified E-class amplifier with resonance components.
Figure 2.11: Modified Class E Amplifier Circuit Diagram
In this configuration, the main function of resonance circuit is to convert the
voltage pulsed waveform coming out of the MOSFET to ac signal [14]. Therefore,
the designed circuit will only amplify the voltage instead of the current.
Output waveform of square wave generators (CGS3311) will be applied to a
driver, which gives the “on” and “off” signals for the MOSFET [15]. The MOSFET
output pulses will then be converted into a sinusoidal high voltage signal by parallel
RLC resonant (class E amplifier) circuit.
The amplifier discontinuous conduction mode is determined by the two
possible power switch operating modes. During the ON state (S = ON), the resonant
19
circuit is only governed by LR and CR, with CT playing the role of a voltage supply.
Thus, the frequency response is
(2.2)
During the OFF state (S = OFF), the resonant circuit is governed by LR, CR
and CT. The current signal I will supply the resonant circuit and the frequency
response is
(2.3)
The transistor acts as a switch with a duty ratio D and a work frequency f is
limited by (f1 < f < f2). The S can be expressed by
(2.4)
The circuit performance will have two different frequencies according to the
state of S. The capacitive parameter for MOSFET will be fixed according to
MOSFET manufacture. Hence, CT has got a fixed value which can be calculated
directly from the datasheet provided by the manufacturer. Thus, the resonant network
parameter LR and CR can be obtained by:
(2.5)
(2.6)
The experimental output waveform of voltages and current for above the
circuit are shown in figure 2.12:
20
Figure 2.12: (a) Experimental and (b) numerically simulated waveforms (c) output
voltage vs. output current
The magnitude of the voltage gain of the amplifier output with respect to the
normalized voltage input and the parametric values CR and R is shown in Figure
2.13. The maximal values of the output voltage gain response surface occur at CR =
100 pF and R > 10 kΩ. Although these conditions would ideally ensure the optimal
amplifier response, the produced peak voltage signal can easily surpass the drain-tosource breakdown voltage of the RF power MOSFET.
21
Figure 2.13: Output voltage maximal gain response surface as a function of CR and R.
Thus, to prevent transistor damage, the nearest commercial value of the
calculated CR was taken, considering that the simulated output voltage level is
sufficient to exceed the typical gas breakdown voltage of helium and maintain a
stable electric discharge.
The response of the proposed system can be determined by the projection of
output variables at an experimentally established CR = 120 pF value. When the
system is used to supply a resistive–capacitive DBD reactor, a parallel plate reactor,
or a plasma needle, a slight variation is introduced to the amplifier load circuit as a
consequence of the physical structure of the discharge device and the discharge
breakdown itself. Before the electric discharge is stabilized, the resistive component
of the plasma needle device diminishes drastically from 2−3 MΩ down to 10−20 kΩ,
as was investigated in the case of a plasma needle reactor [11]. As for the case of a
DBD reactor, there exists a reduction of its internal resistance from a no energized
circuit of 200−300 kΩ to roughly 10−12 kΩ once the plasma is established.
When the load resistance diminishes, the amplifier optimal operation point
moves back to the front of the gain response surface along the R-axis, describing a
line of quasi-constant value gains, as can be seen represented by a white arrowed line
22
in Figure 2.13. Thus, one can consider for a constant CR that the voltage gain of the
amplifier remains practically constant vis-à-vis of any resistive load variation from
an open circuit to 10 kΩ while, for lower resistive values, the response gain drops
more quickly. Furthermore, the plasma needle capacitance measured with an Agilent
model 4263B LCR Bridge is around 5.8−6.0 pF. As this parameter is too small
compared with CR, then, its variations do not affect significantly the resonant
behaviour of the LC circuit.
Thus, the proposed amplifier configuration can assimilate both the typical
resistive and capacitive variations of a plasma needle or even DBD reactors into its
function characteristics. This self-coupling feature facilitates the use of the amplifier
as a supply system to generate the devices of room pressure no equilibrium plasmas
both with resistive and capacitive–resistive loads, making the use of an intermediate
matching stage redundant, as is usually done.
Another important point is that the maximal power can be found at air gap
space of 1.5mm [10]. Figure 2.14 show different applied voltage and air gap space.
Figure 2.14: Discharge power as function of Reactor Gap
CHAPTER 3
RESEARCH METHODOLOGY
3.1
Introduction
This particular chapter is going to discuss about the methodology followed to
successfully achieve the high frequency power supply for skin cancer treatment. Subtitles involved at this chapter is methodology technique, associated guidelines and
datasheet, and software used for modelling. Methodology procedure will certainly
provide all essential ways to complete the design in a simple flow chart. Strategies
and datasheets that associated to the design will be study as well. The software
utilized in this project are MATLAB/Simulink R2012a and Multisim 11.0.
In early stages, some intensive study was conducted for E-class amplifier
theory through reading books, papers and thesises. After comprehensive
understanding of E-class amplifier, simulation study was conducted using
MATLAB/Simulink R2012a. The results of MATLAB/Simulink R2012a are then
compared with some papers studied the same research. The non-thermal plasma will
be tested with no need for impedance matching network as the modified E-class
amplifier function well without need for it.
24
3.2
Methodology Procedure
The design of radio frequency power supply had particular steps which
followed to achieve the desired results as shown in the flow chart in figure 3.1.
START
Preliminary Studies
System Simulation
NO
Adjustments
Success
YES
System
Development
Checking the system
performance
NO
Adjustments
Success
YES
END
Figure 3.1: Procedure Flow Chart
25
3.3
Related Strategies
Associated papers and journals have been reviewed carefully in order to
achieve the desired design of the power supply system. The actual conditions of
proposed plasma setup is going to be designed according to the current plasma setup
invented by Eva Stoffels and her team. The same process will be applied to design
the radio frequency system. The actual design of the radio frequency will be based on
the modified E-class along with parallel resonant circuit.
3.4
Modelling Software
Throughout the whole project, MATLAB/Simulink R2012a will be used to
design and simulate the proposed Plasma Radio Frequency Source. For verification,
MULTISIM 11 will be used to simulate the proposed system.
3.4.1
MATLAB/Simulink R2012a
Simulink is a block diagram environment for multidomain simulation and
Model-Based Design. It supports system-level design, simulation, automatic code
generation, and continuous test and verification of embedded systems.
Simulink provides a graphical editor, customizable block libraries, and
solvers for modelling and simulating dynamic systems. It is integrated with
MATLAB, enabling you to incorporate MATLAB algorithms into models and export
simulation results to MATLAB for further analysis.
26
MATLAB R2012a provides the reliable circuit design for expertise. It keeps
improving to ensure the circuit designers and researchers can move faster to the stage
of PCB production. One of the advantages of circuit design by using this software is
the designers will have the accurate part selection. MATLAB has the database of
more than 22,000 components from top semiconductor manufacturers such as
Analogy Devices, National Semiconductor, NXP, ON Semiconductor, and Texas
Instruments.
Besides, the proposed circuit could also be validated using other software
such MULTISIM or LABVIEW which are in same family coming from NI
manufacturer.
The reasons behind choosing MATLAB is for the advantages
mentioned above and moreover its availability, where we can have a UTM licenced
copy of MATLAB 2012a
Throughout this project, Simulink section of MATLAB is going to be used
to simulate the proposed circuit. The Simulink provides us with very convenient
tools which have wide variety of options which could utilized to perform analysis to
an electrical system.
The proposed circuit has been first drawn schematics using the Simulink.
All typical components are available in Simulink library. Then using the scope tool
to display the output results and show parameters which are the essential parameters
of the system such as the output voltage and current.
3.5
Hardware Implementation
Throughout the project, development of the system has gone through several
stages. The first stage was about the selection of the system components. It was
started with searching for selected components in the local shops within Johor, then
searching within the entire Malaysia. Some components were not found within local
27
shops in Malaysia, so they have been ordered from online components store in
Singapore. System development was done based on High Voltage Laboratory.
The second stage was to develop the function generator circuit. Based on
High Voltage Laboratory, implementation of the function generator has been done.
The function generator focuses in generating square wave signal only via utilizing
the IC chip SG3525. The main function of the square wave is to provide driving
signal for the MOSFET for switching process. This circuit section has been tested
and examined on the breadboard, results have been recorded and discussed in
Chapter 5.
The next stage was developing of the Power MOSFET Driver circuit. The
driver circuit was developed by using the IC chip TC4427, which is low side drive
with high frequency potential. The developed circuit section have been tested and
examined on the breadboard, results has been recorded.
The Final stage was developing the E-class Amplifier circuit which includes
the implementation of Power MOSFET circuit and the resonance circuit. E-class
amplifier was developed based on the designed and simulated circuit which will be
discussed later in Chapter 5.
MOSFET IRF540N has been employed during
implementation of the E-class amplifier. The E-class amplifier circuit was combined
with the other circuit section in order to the test and examine the overall system
performance. The combined system has be tested and examined, results has been
recorded and discussed in later chapters.
The methodology followed for hardware implementation can be summarized in some
points:
(i)
Selection of components manufactures.
(ii)
Start implementing the function generator circuit with IC SG3525 which
provides high frequency switching up to 1 MHz with square wave signals.
The development was initiated at breadboard using the IC chip and several
wire jumpers for necessary external connection. Detailed connection of the
circuit is explained later in next chapter.
28
(iii)
After development of function generator, the circuit of Power MOSFET
driver had been developed successfully using the IC TC4427 and some
external wires for necessary connection. Detailed connection of IC
TC4427 is represented in the next chapter.
(iv)
Finally, the main circuit of power MOSFET and the resonant circuit had
been implemented. The main circuit has an input coming from the output
of Driver TC4427, and output voltage signal of sine wave.
CHAPTER 4
RADIO FREQUENCY POWER SUPPLY DESIGN
4.1
Introduction
This chapter discusses about the design of radio frequency power supply for
skin cancer treatment. This project targets to design a radio frequency power supply
which can produce a voltage up to 200V with the frequency range of 300 KHz – 1
MHz. The design was initiated with the software simulation and following by
hardware development. The simulation and hardware development is going to be
discussed in details.
4.2
Simulation Development
Radio Frequency power supply design is initiated with program simulation.
The main purpose of the simulation is verify the designed circuit whether the circuit
performance is within the aimed specification, and to ensure it performing well prior
to hardware development. Throughout this project, MATLAB Simulink R2012a and
MULTISIM 11.0 were used to verify the circuit designed.
30
4.3
Proposed E-Class amplifier Simulation
(a
)
(b)
Figure 4.1: Modified Class E Amplifier Simulation Circuit using (a)
MATLAB/Simulink and (b) Multisim 11.0
31
The proposed modified E-class amplifier is shown in figure 4.1 above, where
in (a) the circuit design via MATLAB and in (b) the circuit design via Multisim. As
it can be seen from the figure above, the circuit design is too simple, however the
circuit is capable of producing high voltage along with high frequency in order to
ensure the conditions for producing non-thermal plasma to be used for skin can
treatment.
The circuit element L is performing as a choke inductor for filtering the DC
input voltage to whole circuit. The filtering process involve permitting the DC
signals to go through and block other harmonics. While the RLC LOAD which
encloses R, Lr and Cr are together comprise the so-called resonant circuit. The major
function of the resonant circuit is to provide selective operating frequency which is
typically in range of (0.3 – 1) MHz.
The resonant circuit setting can be control according to selective frequency
by implementing the following formula:
𝑓=
1
2𝜋 𝐿𝑟 𝐶𝑟
(4.1)
The typical value rang for the output voltage is around 200-600 Vpp which is
the one of essential requirement for generating non-thermal plasma. The relation
between the voltage and the necessary helium flow is inversely proportional. The
relationship leads to higher voltage level when the helium gas necessary to generate
the non-thermal plasma. On other hands, the lower voltage level required higher
level of helium gas. The lower helium gas level, the cheaper cost of generating
plasma as it leads to generate the high voltage.
Based on provided datasheets, Radio-Frequency Power MOSFET IRF540N
has got value of
in range of 2.5 to 5.5 V. Therefore, the 5Vp square wave
input signal is enough used to drive the MOSFET in simulation. For precaution, 10
Vp was used instead of 5Vp.
32
The square wave form was generated and then directly plug into the
MOSFET with no need to go through the Power driver during the simulation study.
The reason behind is in MATLAB software is able to generate the square wave
typically without any harmonics that may degraded the voltage level required by the
power MOSFET. According to the datasheet of MOSFET, the MOSFET gate to
source Capacitance
, which is about 210 pF, is needed to charge to a critical
voltage level which
, that is needed to start the conduction mode from the drain to
source.
However, the hardware implementation of design, there is a need to install
POWER DRIVER TC2247 prior to MOSFET connection. The input of the driver is
the output of function generator IC, while its output is plugged into as input for the
MOSFET. The input of MOSFET, as shown in figure above, is at GATE pin. While
the source pin is certainly will be grounded, and the drain pin is getting connected to
DC supply through the choke inductor L.
The function generator which has been used throughout this project is
SG3525AN. This IC is about to generate range of frequencies typically in (200 KHz
– 1MHz). The input voltage to this IC is about 18 V, while the output voltage drawn
is about 5-10 Vp. The details pins configuration of this IC will be explained
thoroughly coming section.
The simulated Tektronix Oscilloscope was utilized throughout this project in
simulation software to perform visualize the output from the proposed circuit. Since
simulated Tektronix Oscilloscope has got 4 probes, it could stand four different
output signal waveform at the same time. Through this project, only 2 outputs signals
are needed to be shown at the same time.
33
4.4
Development of hardware system
Directly after successfully simulating the proposed circuit, development of
hardware was started and selection of components needed throughout this project. It
was started with frequency waveform generator circuit section, then POWER
DRIVER circuit design and finally MOSFET (main circuit) design circuit section.
The following sub-sections give deeper look for each circuit section.
4.4.1 Square Wave Function Generator
Figure 4.2: Block Diagram of SG3525 Waveform generator
Figure 4.2 shows the detailed block diagram of IC function generator
SG3525. This IC is capable of providing high frequency square wave with certain
amplitude of 5-10Vp which is necessary to drive the MOSFET ON & OFF. The
process of generating the square wave is following PWM modulating technique. The
basic principle is that it compare between two fundamental signal and the output will
34
according to comparing results. The first signal is generated at pin 6, which can
easily be controlled via controlling the component resistor RT as shown in figure
above.
Figure 4.3: Pin connection of SG3525 Waveform generator
While the other signal is the triangular wave form which is generated at pin 5.
The triangular wave form can also be conveniently controlled by adjusting the value
of component CT. both components, RT and CT are responsible for controlling the
operating frequency f. the relationship between them is given by the following
formula :
𝑓=
1
0. 𝑅T 𝐶T
(4.2)
Besides, the operating frequency can easily be determined through looking at
the certain graph given in the datasheet which is provided by the chip manufacturer.
The graph is drawn based on several experiments conducted by the manufacturer in
order to ease the selection of both components, RT and CT, and therefore ease the
selection for operating frequency, f. In practical, choosing the components values
based on the graph is more convenient than calculating it through the formula given
above.
35
Figure 4.4: Relationship between RT, CT and frequency for SG3525
Figure 4.4 above demonstrates the relationship between the controlling
components, RT, CT, and operating frequency, f. The graph is based on bode plot
technique. As stated above, the graph provide a quick method to determine the
controlling components along with corresponding operating frequency. For instance,
to select operating frequency of 350 KHz, we can use the line of CT = 1.0 nF, which
intersects with RT = 2.9 KΩ.
The MOSFET IRF540N needs a low voltage level of 5-10 Vp output from the
function generator. Therefore, connection of IC SG3525 should be designed
according to provided datasheet with some modification on the external connection
on the IC chip. Such modification may include leaving pin3 and pin4 open and not
connected, connection of CT and DISC (pin7) should be same and connection of VC
and Vref should be throughout a voltage divider voltage resistors. All these
modification enables us to get the desired output with high efficiency and optimum
working performance. The input voltage, which is about 18 Vp, should not exceed 30
Vp as it has limit thermal ability withstand up to 30Vp.
36
18 V
VO
R
C
Figure 4.5: SG3525 Hardware implementation
Figure 4.5 depicts the connection of hardware circuit of SG3525. The 18 Vp
input voltage is directly connected to pin 15, with two capacitors, 10 uF & 0.1 uF,
connected in parallel along with it. The two capacitors are performing as filter to
allow only DC and preventing AC harmonic signal to get in the circuit. Also, the
voltage reference at pin13, Vref is connecting with two capacitors, 10 uF & 0.1 uF,
in parallel as same as those in pin 15. The general function of these capacitors is to
reduce the noise and stabilize the performance of IC chip.
4.4.2 Power MOSFET driver
Figure 4.6: TC4427 MOSFET driver block diagram
37
Figure 4.7: TC4427 MOSFET driver connection circuit
Figure 4.6 and figure 4.7 show the overall connection circuit and the block
diagram of the TC4427 MOSFET driver. This IC is low side ultrafast Radio
frequency MOSFET driver. The IC is capable to drive the MOSFET with frequency
up to 20 MHz. The main purpose of the driver is to amplify the output of the
SG3525, and also to provide isolation between main circuit and function generator
circuit section.
As shown in figure 4.7, the connection of driver is very simple yet has an
excellent ability to drive with high frequency. Input of TC4427, which is coming
from the output of SG3525, is directly plugged into pin2. While the output is
collected at pin 7, which in turn connected in parallel to 1000 pF capacitor in order to
reduce the noise and ensure stability of the performance. The TC4427 has operating
voltage of 18 Vp, which same with operating voltage of SG3525. To reduce the
clatter of input supply, capacitors of 4.7 uF and 0.1 uF, are connected to parallel with
the input supply.
38
The typical value of output capacitor, CL, is in range of 100 uF – 10,000 uF
depending mainly on the input operating voltage and frequency of overall system. It
also depends on the factor but in minor form such the output current, Io, and current
supply which both have typical values in mAmp. The figure 4.8 shows the selective
graph for load capacitor, CL.
Figure 4.8: relationship between Capacitor Load and supply current
18 Vp
Input of TC4427
Output
Figure 4.9: TC4427 Hardware connection
39
The figure 4.9 shows the hardware implementation of the TC4427 POWER
MOSFET driver. The connection is based on circuit connection provided in the
datasheet of the driver, as shown in figure 5.6. The input voltage for the driver is 18
Vp, connected directly to node of input of SG3525, while the output is taken from
pin7 and directly plugged into the gate pin of the MOSFET. The output of the driver
will be almost same as the VDD which is about 15 Vp. The output is nearly out of
noise and stable because of 1000pF capacitor parallel connected to it.
4.4.2 Entire Modified E-Class Amplifier
Figure 4.10: Plasma Source Setup Hardware implementation
Figure 4.10 shows the overall setup for plasma used to generate the nonthermal plasma that can be utilized for skin cancer treatment. The connections are all
based on the designed circuit. The plasma output is taken from the power MOSFET
after being went through the resonance circuit to convert the switched pulsed to sine
wave to be used. The overall the performance characteristics are about 300 Vpp and
350 KHz.
CHAPTER 5
RESULTS AND DISCUSSION
5.1
Introduction
This chapter discusses about the results obtained from both simulation and
experimental conducted throughout the project. The chapter will start with simulation
results of E-class modified amplifier which will enclose results from SG3525
followed by TC4427 and end with overall system performance. After this, hardware
results will be presented although for each circuit section. The output of MOSFET
will combined with E-class amplifier to form the high voltage and the high frequency
output. The results obtained from the experimental will be compared with simulation
results.
41
5.2
Simulation Results of MATLAB/Simulink
Figure 5.1: Function Generator Waveform
Figure 5.1 shows the waveform of the function generator which is typically
square wave signal. The amplitude of square wave is 10 V along with frequency of
375 KHz. This signal level is used to drive the power MOSFET without need for the
power MOSFET driver. The frequency of the function generation will be the same
for the operating frequency and the output frequency. The function generator is
considered the main control tool to adjust the operation frequency at any time.
42
Figure 5.2: Output Current waveform
The simulated output current signal is observed in figure 5.2. The output
current waveform is typical sine wave with amplitude of mAmp range. This shows
the linearity of relationship of the current and voltage. Output frequency is about 349
KHz as it observed in figure 5.2 above.
As it can be observed, the output current is typically sine wave, however the
shape of the output current can be changed according to the plasma configuration
load applied to the system. However, scope of this research focuses on the output
voltage only.
Figure 5.3 demonstrates the output voltage from the power MOSFET
IRF540N which the pink waveform shown, while the output voltage from the overall
circuit, which is the yellow signal, after being applied to the resonance circuit, which
in turn converts the pulse wave into sine wave as shown above.
43
VC
Vo
Figure 5.3: Simulated waveform of Vc and Vo
The output of the MOSFET is in form of pulse wave and not typical sine
wave form. This is because of the switching process of the MOSFET. The pulse
wave signal is then being applied through resonance circuit which function as
converter it to typical sine wave.
The output voltage signal is typically a sine waveform without any noise or
harmonic noticed in the signal. The reason behind this is of the assumption that all
the proposed circuit components are ideal. As observed, the amplitude of output
voltage is about 400 Vpp along with corresponding operating frequency of 350 KHz.
44
5.3
Simulation Results of MUTISIM 11.0
Figure 5.4: Simulated waveform of VO
MULTISIM simulation results of the output voltage is shown in figure 5.4. It can be
seen that the output voltage of simulated voltage using MULTISIM is identical with
the simulated output voltage using MATLAB/Simulink. The output voltage having
amplitude of 372 Vpp along with no noise or harmonics appeared on the waveform.
45
Figure 5.5: simulated waveform of VO
Figure 5.5 shows the simulated output voltage from MULTISIM 11.0 with
frequency measurement. The figure shows that the output voltage has actual value of
frequency around of 350 KHz. This results is typically identical to the results
obtained from the MATLAB/Simulink Simulation.
46
5.4
Hardware Development Results
5.4.1
Function Generation Output
(a)
(b)
Figure 5.6: output waveform of SG3525 (a) 307 KHz (b) 930 KHz
Figure 5.6 shows the hardware results of the function generator IC SG3525 at
different frequencies levels. As stated before, the frequency of the system can be
varied via controlling elements RT and CT. The results show the ability of IC to
47
generate square wave signal at high frequencies. Noise and instabilities can be
observed from the figure above as the all elements are not ideal and then they
contribute some noise to output waveform. Because of low cost of IC SG3525, using
SG3525 to generate square wave form will be very economic.
5.4.2
Power MOSFET Driver Output
Figure 5.7: output waveform of TC4427
Figure 5.7 shows the output waveform of TC4427 POWER MOSFET Driver
at frequency 307 KHz. It can be observed that the output of driver is more uniform
than the output of function generator. It has amplitude of about 1.4 (x10 probe) 14
Vpp along with frequency of 307 KHz appeared in the figure above. The output is
decreased from 18 Vp, typical value, about 4 V. However, very good shape of square
wave can be observed.
48
5.4.3
Complete E-Class Amplifier Output
(a)
\
(b)
Figure 5.8: output waveform of overall circuit (a) 307 KHz (b) 910 KHz
Figure 5.8 shows the output wave form of the overall circuit design. The
waveform is typically sine wave with some noise observed in the signals. The
voltage amplitude of output voltage is about 3.75(x100 probe) 375 Vpp along with
49
two different frequencies of 910 KHz and 285 Vpp at 307 KHz. It be observed that
the voltage amplitude is increased with increase of frequency. The reason behind this
is because of the switching process of the MOSFET.
CHAPTER 6
CONCLUSION AND RECOMMENDATION
6.1
Conclusion
Through this chapter, some basic concepts of the projects will be reviewed
and a conclusion will be drawn based on the results. Beside, Some Future
recommendation for future research will be presented and initiated.
Non-thermal plasma treatment of living tissues grow into a current issue in
contemporary plasma physics and in medical sciences. The plasma is able of bacteria
decontamination and non-inflammatory tissue modification, which leads it to be an
gorgeous implement for wound healing and the treatment of skin diseases and dental
caries. The current method known to generate the non-thermal plasma at plasma
needle is considered involve a very high cost due to the commercialize function
generator and research amplifier. Both of these equipment’s are special for the
multipurpose of research and study so a much cheaper, simpler power supply should
be developed to specifically generate the non-thermal plasma for future application.
51
This project research had presented full design of the non-thermal plasma
source suitable for skin cancer treatment. The first objective of the project, which is
to design the circuit to perform as source for generating non-thermal plasma, has
been successfully achieved.
Second objective, which about the simulation study using software like
MATLAB and MULTISIM 11.0, has fulfilled as well. All results above showed the
perfectness and competitive of the software to simulate the system. Simulation has
been for each parts individually, and results are presented for each part as well.
Third objective of developing the proposed radio frequency power supply has
been successfully accomplished. The recorded results has proved the system ability
to generate radio frequency sine wave with the desired conditions which could be for
producing the non-thermal plasma.
6.2
Recommendation
The recommendations for future work to improve the power supply of plasma
needle and to investigate the plasma needle as a potential application to replace some
of the bio-medical instrument are:
(i)
SG3525 is able to generate the output waveform at high frequency. It can
be used to replace the function generator in the power supply circuit.
However, SG3525 is no longer manufactured by MOTOROLA and it is
hard to buy a large amount of SG3525 in the market. Due to this reason, an
alternative for SG3525 should be found.
(ii)
According to [6], the reflection of the electromagnetic waves occurs at the
point in the network where the impedance changes and this will interrupt
the power transfer of the whole circuit. Therefore matching network
should be introduced into the circuit to match the input and output
52
impedances in order to reduce the effect of reflected power and provide a
higher efficiency in term of power transfer.
(iii)
For RF design, switching losses and limitation of switching speed always
become the problem of optimum design. To overcome this problem, every
element in the circuit plays an important role especially the MOSFET
which is the actual switching devices. So, a RF MOSFET should be used
in the circuit as it can provide many features suitable for RF design to
optimize the high speed switching and provide an excellent thermal
transfer.
53
REFERENCES
1. M K Boudam, M. M., B Saoudi, C Popovici, N Gherardi and F Massines (2006).
Bacterial Spore Inactivation by Atmospheric-Pressure Plasma in the Presence or
Absence of UV Photons as Obtained with the Same Gas Mixture.
2. Kieft, I. E., M. Kurdi, et al. (2006). Reattachment and Apoptosis after PlasmaNeedle Treatment of Cultured Cells. Plasma Science, IEEE Transactions on 34(4):
1331-1336.
3. Roxana Silvia Tipa, G. M. W. K. (2011). Plasma-Stimulated Wound Healing.
IEEE Transactions On Plasma Science 39(11): 2978-2979.
4. Laroussi, M. (2009). Low-Temperature Plasmas for Medicine? Plasma Science,
IEEE Transactions on 37(6): 714-725.
5. E Stoffels, A. J. F., W W Stoffels and G M W Kroesen (2002). Plasma needle: a
non-destructive atmospheric plasma source for fine surface treatment of
(bio)materials. Plasma Sources Science And Technology 11: 383-388.
6. H Conrads, M. S. (2000) Plasma generation and plasma sources. 9, 441-454
7. I.E.Kieft (2005). Plasma Needle: exploring biomedical applications of
nonthermal plasmas, Printservice Technische Universiteit Eindhoven: 153.
54
8. Moisan, M., J. Barbeau, et al. (2001). Low-temperature sterilization using gas
plasmas: a review of the experiments and an analysis of the inactivation
mechanisms. International Journal of Pharmaceutics 226(1–2): 1-21.
9. M K Boudam, M. M., B Saoudi, C Popovici, N Gherardi and F Massines (2006).
Bacterial spore inactivation by atmospheric-pressure plasma in the presence or
absence of UV photons as obtained with the same gas mixture.
10. Sladek, R. E. J., E. Stoffels, et al. (2004). Plasma Treatment of Dental Cavities:
A Feasibility Study. Plasma Science, IEEE Transactions on 32(4):
1540-1543.
11. Ingrid E. Kieft, D. D., Anton J.M. Roks and Eva Stoffels (2005). Plasma
Treatment of Mammalian Vascular Cells: A Quantitative Description. IEEE
Transactions on Plasma Science 33(2): 771-775.
12. D. Kim, B. G., D.B. Kim, W. Choe and J.H. Shin (2009). A Feasibility Study for
the Cancer Therapy Using Cold Plasma. ICBME: 355-357.
13. Sokal, N. O. (Jan/Feb 2001) Class-E RF Power Amplifiers. QEX: 9-20.
14. Rosendo Peña-Eguiluz, M., IEEE, José Arturo Pérez-Martínez, Régulo
López-Callejas, and J. S.-P. Antonio Mercado-Cabrera, Blanca AguilarUscanga, Arturo E. Muñoz-Castro, Raúl Valencia-Alvarado, Samuel R.
Barocio-Delgado, Benjamín G. Rodríguez-Méndez, and Aníbal de la PiedadBeneitez (2010). Analysis and Application of a Parallel E-Class Amplifier as
RF Plasma Source. IEEE Transactions on Plasma Science 38(10).
15. Jose A. Perez-Martinex, R. P.-E., Regulo Lopez-Callejas, Antonio MercadoCabrera, Raul Valencia Alvarado, Samuel R. Barocio, Anibal de la PiedadBeneitez (2008). Power Supply for Plasma Torches Based on a Class-E
Amplifier Configuration.
55
16. Sadafi, H. A. (1998). The Therapeutic Applications of Pulsed and Static
Magnetic Fields. 2nd International Conference on Bioelectromagnetism.
Melbourne, Australia.
17. Albert Roy Davis and Walter C. Rawls, J. (1988). The Magnetic Effect and
Magnetism and Its Effects on the Living System, Exposition Press.
18. Ven, G. v. d. (2006). BEP: Design of a guiding mechanism for the plasma
needle”, Technische Universiteit Eindhoven.
19. Abhijit D. Pathak, S. O. (2003). Unique MOSFET/IGBT Drivers and Their
Applications in Future Power Electronics Systems. Power Electronics and
Drive Systems, PEDS 2003. 1: 85-88.
20. Abhijit D. Pathak (2001). MOSFET/IGBT Drivers, Theory and Applications,
IXYS Corporation.
21. Zirnheld, J. L., S. N. Zucker, et al. (2010). Nonthermal Plasma Needle:
Development and Targeting of Melanoma Cells. Plasma Science, IEEE
Transactions on 38(4): 948-952.
22. Lo Keat How (2011). Modeling And Design of Plasma Needle Supply. IVAT.
Johor, Universiti Teknologi Malaysia. Bachelor of Engineering (Electrical).
23. E.Cerchar, K.Arjunan, E.Podolsky, J.Azizkhan Clifford, A.Fridman, G.Friedman
(2012) Selectivity of Non-Thermal Atmospheric Pressure Microsecond Pulsed
Dielectric Barrier Discharge Plasma Induced Apoptosis in Malignant Cells over
Normal Cells, Plasma Medicine Press
24. S. Kalghatgi, C.Kelly, E.Cerchar, J.Azizkhan-Clifford, A. Fridman, G. Friedman
(2012), DNA Damage in Mammalian Cells by Non-Thermal Atmospheric Pressure
Microsecond Pulsed Dielectric Barrier Discharge Plasma is not mediated by Ozone.
Plasma Processes and Polymers,
56
APPENDIX A
COMPONENTS DATASHEETS
PD - 91341B
IRF540N
HEXFET® Power MOSFET
l
l
l
l
l
l
Advanced Process Technology
Ultra Low On-Resistance
Dynamic dv/dt Rating
175°C Operating Temperature
Fast Switching
Fully Avalanche Rated
D
VDSS = 100V
RDS(on) = 44mΩ
G
ID = 33A
S
Description
Advanced HEXFET® Power MOSFETs from International
Rectifier utilize advanced processing techniques to achieve
extremely low on-resistance per silicon area. This benefit,
combined with the fast switching speed and ruggedized
device design that HEXFET power MOSFETs are well
known for, provides the designer with an extremely efficient
and reliable device for use in a wide variety of applications.
The TO-220 package is universally preferred for all
commercial-industrial applications at power dissipation
levels to approximately 50 watts. The low thermal
resistance and low package cost of the TO-220 contribute
to its wide acceptance throughout the industry.
TO-220AB
Absolute Maximum Ratings
Parameter
ID @ TC = 25°C
ID @ TC = 100°C
IDM
PD @TC = 25°C
VGS
IAR
EAR
dv/dt
TJ
TSTG
Continuous Drain Current, VGS @ 10V
Continuous Drain Current, VGS @ 10V
Pulsed Drain Current 
Power Dissipation
Linear Derating Factor
Gate-to-Source Voltage
Avalanche Current
Repetitive Avalanche Energy
Peak Diode Recovery dv/dt ƒ
Operating Junction and
Storage Temperature Range
Soldering Temperature, for 10 seconds
Mounting torque, 6-32 or M3 srew
Max.
Units
33
23
110
130
0.87
± 20
16
13
7.0
-55 to + 175
A
W
W/°C
V
A
mJ
V/ns
°C
300 (1.6mm from case )
10 lbf•in (1.1N•m)
Thermal Resistance
Parameter
RθJC
RθCS
RθJA
www.irf.com
Junction-to-Case
Case-to-Sink, Flat, Greased Surface
Junction-to-Ambient
Typ.
Max.
Units
–––
0.50
–––
1.15
–––
62
°C/W
1
03/13/01
IRF540N
Electrical Characteristics @ TJ = 25°C (unless otherwise specified)
RDS(on)
VGS(th)
gfs
Parameter
Drain-to-Source Breakdown Voltage
Breakdown Voltage Temp. Coefficient
Static Drain-to-Source On-Resistance
Gate Threshold Voltage
Forward Transconductance
IDSS
Drain-to-Source Leakage Current
V(BR)DSS
∆V(BR)DSS/∆TJ
Qg
Qgs
Qgd
td(on)
tr
td(off)
tf
Gate-to-Source Forward Leakage
Gate-to-Source Reverse Leakage
Total Gate Charge
Gate-to-Source Charge
Gate-to-Drain ("Miller") Charge
Turn-On Delay Time
Rise Time
Turn-Off Delay Time
Fall Time
LD
Internal Drain Inductance
LS
Internal Source Inductance
Ciss
Coss
Crss
EAS
Input Capacitance
Output Capacitance
Reverse Transfer Capacitance
Single Pulse Avalanche Energy ‚
IGSS
Min. Typ. Max. Units
Conditions
100 ––– –––
V
VGS = 0V, ID = 250µA
––– 0.12 ––– V/°C Reference to 25°C, I D = 1mA
––– ––– 44
mΩ VGS = 10V, ID = 16A „
2.0
––– 4.0
V
VDS = VGS , ID = 250µA
21
––– –––
S
VDS = 50V, ID = 16A„
––– ––– 25
VDS = 100V, VGS = 0V
µA
––– ––– 250
VDS = 80V, VGS = 0V, TJ = 150°C
––– ––– 100
VGS = 20V
nA
––– ––– -100
VGS = -20V
––– ––– 71
ID = 16A
––– ––– 14
nC
VDS = 80V
––– –––
21
VGS = 10V, See Fig. 6 and 13
–––
11 –––
VDD = 50V
–––
35 –––
ID = 16A
ns
–––
39 –––
RG = 5.1Ω
–––
35 –––
VGS = 10V, See Fig. 10 „
Between lead,
4.5 –––
–––
6mm (0.25in.)
nH
G
from package
–––
7.5 –––
and center of die contact
––– 1960 –––
VGS = 0V
––– 250 –––
VDS = 25V
–––
40 –––
pF
ƒ = 1.0MHz, See Fig. 5
––– 700… 185† mJ IAS = 16A, L = 1.5mH
D
S
Source-Drain Ratings and Characteristics
IS
ISM
VSD
trr
Qrr
ton
Parameter
Continuous Source Current
(Body Diode)
Pulsed Source Current
(Body Diode)
Diode Forward Voltage
Reverse Recovery Time
Reverse Recovery Charge
Forward Turn-On Time
Min. Typ. Max. Units
Conditions
D
MOSFET symbol
33
––– –––
showing the
A
G
integral reverse
––– ––– 110
S
p-n junction diode.
––– ––– 1.2
V
TJ = 25°C, IS = 16A, VGS = 0V „
––– 115 170
ns
TJ = 25°C, IF = 16A
––– 505 760
nC
di/dt = 100A/µs „
Intrinsic turn-on time is negligible (turn-on is dominated by LS+LD)
Notes:
 Repetitive rating; pulse width limited by
max. junction temperature. (See fig. 11)
‚ Starting TJ = 25°C, L =1.5mH
RG = 25Ω, I AS = 16A. (See Figure 12)
ƒ ISD ≤ 16A, di/dt ≤ 340A/µs, VDD ≤ V(BR)DSS,
TJ ≤ 175°C
„ Pulse width ≤ 400µs; duty cycle ≤ 2%.
This is a typical value at device destruction and represents
operation outside rated limits.
† This is a calculated value limited to TJ = 175°C .
2
www.irf.com
IRF540N
1000
1000
VGS
15V
10V
8.0V
7.0V
6.0V
5.5V
5.0V
BOTTOM 4.5V
100
100
4.5V
10
20µs PULSE WIDTH
T = 25 C
1
4.5V
10
10
100
TJ = 25 ° C
100
TJ = 175 ° C
V DS = 50V
20µs PULSE WIDTH
7.0
8.0
Fig 3. Typical Transfer Characteristics
www.irf.com
9.0
R DS(on) , Drain-to-Source On Resistance
(Normalized)
I D , Drain-to-Source Current (A)
3.5
6.0
10
100
Fig 2. Typical Output Characteristics
1000
5.0
1
VDS , Drain-to-Source Voltage (V)
Fig 1. Typical Output Characteristics
VGS , Gate-to-Source Voltage (V)
°
J
1
0.1
VDS , Drain-to-Source Voltage (V)
10
4.0
20µs PULSE WIDTH
T = 175 C
°
J
1
0.1
VGS
15V
10V
8.0V
7.0V
6.0V
5.5V
5.0V
BOTTOM 4.5V
TOP
I D , Drain-to-Source Current (A)
I D , Drain-to-Source Current (A)
TOP
ID = 33A
3.0
2.5
2.0
1.5
1.0
0.5
0.0
-60 -40 -20
VGS = 10V
0
20 40 60 80 100 120 140 160 180
TJ , Junction Temperature ( °C)
Fig 4. Normalized On-Resistance
Vs. Temperature
3
IRF540N
VGS = 0V,
f = 1MHz
Ciss = Cgs + Cgd , Cds SHORTED
Crss = Cgd
Coss = Cds + Cgd
C, Capacitance (pF)
2500
Ciss
2000
1500
1000
C
oss
500
20
VGS , Gate-to-Source Voltage (V)
3000
ID = 16A
V DS = 80V
V DS = 50V
V DS = 20V
16
12
8
4
Crss
FOR TEST CIRCUIT
SEE FIGURE 13
0
0
1
10
0
100
60
80
1000
ID, Drain-to-Source Current (A)
1000
ISD , Reverse Drain Current (A)
40
Fig 6. Typical Gate Charge Vs.
Gate-to-Source Voltage
Fig 5. Typical Capacitance Vs.
Drain-to-Source Voltage
OPERATION IN THIS AREA
LIMITED BY R DS(on)
100
100
TJ = 175 ° C
10
TJ = 25 ° C
1
0.1
0.2
20
QG , Total Gate Charge (nC)
VDS , Drain-to-Source Voltage (V)
V GS = 0 V
0.6
1.0
1.4
VSD ,Source-to-Drain Voltage (V)
1.8
100µsec
10
1msec
1
T A = 25°C
10msec
T J = 175°C
Single Pulse
0.1
1
10
100
1000
VDS , Drain-toSource Voltage (V)
Fig 7. Typical Source-Drain Diode
Forward Voltage
4
Fig 8. Maximum Safe Operating Area
www.irf.com
IRF540N
35
RD
VDS
I D , Drain Current (A)
30
VGS
D.U.T.
RG
25
+
-VDD
20
VGS
Pulse Width ≤ 1 µs
Duty Factor ≤ 0.1 %
15
10
Fig 10a. Switching Time Test Circuit
VDS
5
90%
0
25
50
75
100
125
TC , Case Temperature
150
175
( °C)
10%
VGS
Fig 9. Maximum Drain Current Vs.
Case Temperature
td(on)
tr
t d(off)
tf
Fig 10b. Switching Time Waveforms
Thermal Response (Z thJC)
10
1
D = 0.50
0.20
P DM
0.10
0.1
0.05
0.02
0.01
0.01
0.00001
t1
SINGLE PULSE
(THERMAL RESPONSE)
t2
Notes:
1. Duty factor D = t 1 / t 2
2. Peak TJ = P DM x Z thJC + TC
0.0001
0.001
0.01
0.1
1
t1 , Rectangular Pulse Duration (sec)
Fig 11. Maximum Effective Transient Thermal Impedance, Junction-to-Case
www.irf.com
5
IRF540N
400
ID
6.5A
11.3A
BOTTOM 16A
L
VD S
D R IV E R
D .U .T
RG
+
- VD D
IA S
20V
0 .01 Ω
tp
Fig 12a. Unclamped Inductive Test Circuit
V (B R )D SS
tp
A
EAS , Single Pulse Avalanche Energy (mJ)
1 5V
TOP
300
200
100
0
25
50
75
100
125
150
175
Starting TJ , Junction Temperature ( ° C)
Fig 12c. Maximum Avalanche Energy
Vs. Drain Current
IAS
Fig 12b. Unclamped Inductive Waveforms
Current Regulator
Same Type as D.U.T.
50KΩ
QG
12V
.2µF
.3µF
VGS
QGS
D.U.T.
QGD
+
V
- DS
VGS
VG
3mA
IG
Charge
Fig 13a. Basic Gate Charge Waveform
6
ID
Current Sampling Resistors
Fig 13b. Gate Charge Test Circuit
www.irf.com
IRF540N
Peak Diode Recovery dv/dt Test Circuit
+
D.U.T*
ƒ
Circuit Layout Considerations
• Low Stray Inductance
• Ground Plane
• Low Leakage Inductance
Current Transformer
+
‚
-
-
„
+

• dv/dt controlled by RG
• ISD controlled by Duty Factor "D"
• D.U.T. - Device Under Test
RG
VGS
*
+
-
VDD
Reverse Polarity of D.U.T for P-Channel
Driver Gate Drive
P.W.
Period
D=
P.W.
Period
[VGS=10V ] ***
D.U.T. ISD Waveform
Reverse
Recovery
Current
Body Diode Forward
Current
di/dt
D.U.T. VDS Waveform
Diode Recovery
dv/dt
Re-Applied
Voltage
Body Diode
[VDD]
Forward Drop
Inductor Curent
Ripple ≤ 5%
[ ISD ]
*** VGS = 5.0V for Logic Level and 3V Drive Devices
Fig 14. For N-channel HEXFET® power MOSFETs
www.irf.com
7
IRF540N
Package Outline
TO-220AB
Dimensions are shown in millimeters (inches)
2.87 (.11 3)
2.62 (.10 3)
10 .54 (.4 15)
10 .29 (.4 05)
3 .7 8 (.149 )
3 .5 4 (.139 )
-A -
-B 4.69 ( .18 5 )
4.20 ( .16 5 )
1 .32 (.05 2)
1 .22 (.04 8)
6.47 (.25 5)
6.10 (.24 0)
4
1 5.24 (.60 0)
1 4.84 (.58 4)
1.15 (.04 5)
M IN
1
2
1 4.09 (.55 5)
1 3.47 (.53 0)
4.06 (.16 0)
3.55 (.14 0)
3X
3X
L E A D A S S IG NM E NT S
1 - GATE
2 - D R A IN
3 - S O U RC E
4 - D R A IN
3
1 .4 0 (.0 55 )
1 .1 5 (.0 45 )
0.93 (.03 7)
0.69 (.02 7)
0 .3 6 (.01 4)
3X
M
B A M
0.55 (.02 2)
0.46 (.01 8)
2 .92 (.11 5)
2 .64 (.10 4)
2.54 (.10 0)
2X
N O TE S :
1 D IM E N S IO N IN G & TO L E R A N C ING P E R A N S I Y 1 4.5M , 1 9 82.
2 C O N TR O L LIN G D IM E N S IO N : IN C H
3 O U T LIN E C O N F O R M S TO JE D E C O U T LIN E TO -2 20 A B .
4 H E A TS IN K & LE A D M E A S U R E M E N T S D O N O T IN C LU DE B U R R S .
Part Marking Information
TO-220AB
E X A M P L E : TH IS IS A N IR F1 0 1 0
W IT H A S S E M B L Y
LOT C ODE 9B1M
A
IN TE R N A TIO N A L
R E C TIF IE R
LOGO
ASSEMBLY
LOT CO DE
PART NU MBER
IR F 10 1 0
9246
9B
1M
D A TE C O D E
(Y Y W W )
YY = YEAR
W W = W EEK
Data and specifications subject to change without notice.
This product has been designed and qualified for the industrial market.
Qualification Standards can be found on IR’s Web site.
IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105
TAC Fax: (310) 252-7903
Visit us at www.irf.com for sales contact information.03/01
8
www.irf.com
Note: For the most current drawings please refer to the IR website at:
http://www.irf.com/package/
SG3525A
Pulse Width Modulator
Control Circuit
The SG3525A pulse width modulator control circuit offers
improved performance and lower external parts count when
implemented for controlling all types of switching power supplies.
The on−chip +5.1 V reference is trimmed to 1% and the error
amplifier has an input common−mode voltage range that includes the
reference voltage, thus eliminating the need for external divider
resistors. A sync input to the oscillator enables multiple units to be
slaved or a single unit to be synchronized to an external system clock.
A wide range of deadtime can be programmed by a single resistor
connected between the CT and Discharge pins. This device also
features built−in soft−start circuitry, requiring only an external timing
capacitor. A shutdown pin controls both the soft−start circuitry and the
output stages, providing instantaneous turn off through the PWM latch
with pulsed shutdown, as well as soft−start recycle with longer
shutdown commands. The under voltage lockout inhibits the outputs
and the changing of the soft−start capacitor when VCC is below
nominal. The output stages are totem−pole design capable of sinking
and sourcing in excess of 200 mA. The output stage of the SG3525A
features NOR logic resulting in a low output for an off−state.
http://onsemi.com
MARKING
DIAGRAMS
16
PDIP−16
N SUFFIX
CASE 648
SG3525AN
AWLYYWW
16
1
1
16
SOIC−16L
DW SUFFIX
CASE 751G
16
SG3525A
AWLYYWW
1
1
Features
•
•
•
•
•
•
•
•
•
•
A
WL
YY
WW
8.0 V to 35 V Operation
5.1 V 1.0% Trimmed Reference
100 Hz to 400 kHz Oscillator Range
Separate Oscillator Sync Pin
Adjustable Deadtime Control
Input Undervoltage Lockout
Latching PWM to Prevent Multiple Pulses
Pulse−by−Pulse Shutdown
Dual Source/Sink Outputs: 400 mA Peak
Pb−Free Packages are Available*
= Assembly Location
= Wafer Lot
= Year
= Work Week
PIN CONNECTIONS
Inv. Input
1
16 Vref
Noninv. Input
2
15 VCC
Sync
3
14 Output B
OSC. Output
4
13 VC
CT
5
12 Ground
RT
6
11 Output A
Discharge
7
10 Shutdown
Soft−Start
8
9
Compensation
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
 Semiconductor Components Industries, LLC, 2005
January, 2005 − Rev. 5
1
Publication Order Number:
SG3525A/D
SG3525A
16
Vref
15
Reference
Regulator
VCC
12
VC
13
To Internal
Circuitry
Under−
Voltage
Lockout
Ground
OSC Output
NOR
4
3
Sync
RT
Output A
Q
6
F/F
Oscillator
Q
NOR
5
CT
Discharge
14
Output B
7
R
9
Compensation
11
1
INV. Input
2
Noninv. Input
−
Error
Amp
+
+
− PWM
−
S
Latch
SG3525A Output Stage
S
50A
VREF
8
CSoft−Start
10
Shutdown
5.0k
5.0k
Figure 1. Representative Block Diagram
ORDERING INFORMATION
Package
Shipping†
SG3525AN
PDIP−16
25 Units / Rail
SG3525ANG
PDIP−16
(Pb−Free)
25 Units / Rail
SG3525ADW
SOIC−16L
47 Units / Rail
SG3525ADWG
SOIC−16L
(Pb−Free)
47 Units / Rail
SG3525ADWR2
SOIC−16L
1000 Tape & Reel
SG3525ADWR2G
SOIC−16L
(Pb−Free)
1000 Tape & Reel
Device
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
http://onsemi.com
2
SG3525A
MAXIMUM RATINGS
Symbol
Value
Unit
Supply Voltage
Rating
VCC
+40
Vdc
Collector Supply Voltage
VC
+40
Vdc
Logic Inputs
−0.3 to +5.5
V
Analog Inputs
−0.3 to VCC
V
±500
mA
50
mA
5.0
mA
Output Current, Source or Sink
IO
Reference Output Current
Iref
Oscillator Charging Current
Power Dissipation
TA = +25°C (Note 1)
TC = +25°C (Note 2)
PD
mW
1000
2000
Thermal Resistance, Junction−to−Air
RJA
100
°C/W
Thermal Resistance, Junction−to−Case
RJC
60
°C/W
TJ
+150
°C
Tstg
−55 to +125
°C
TSolder
+300
°C
Operating Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering, 10 seconds)
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
1. Derate at 10 mW/°C for ambient temperatures above +50°C.
2. Derate at 16 mW/°C for case temperatures above +25°C.
RECOMMENDED OPERATING CONDITIONS
Characteristics
Symbol
Min
Max
Unit
Supply Voltage
VCC
8.0
35
Vdc
Collector Supply Voltage
VC
4.5
35
Vdc
Output Sink/Source Current
(Steady State)
(Peak)
IO
0
0
±100
±400
mA
Reference Load Current
Iref
0
20
mA
Oscillator Frequency Range
fosc
0.1
400
kHz
Oscillator Timing Resistor
RT
2.0
150
k
Oscillator Timing Capacitor
CT
0.001
0.2
F
Deadtime Resistor Range
RD
0
500
Operating Ambient Temperature Range
TA
0
+70
°C
APPLICATION INFORMATION
Shutdown Options (See Block Diagram, page 2)
latch is immediately set providing the fastest turn−off signal
to the outputs; and a 150 A current sink begins to discharge
the external soft−start capacitor. If the shutdown command
is short, the PWM signal is terminated without significant
discharge of the soft−start capacitor, thus, allowing, for
example, a convenient implementation of pulse−by−pulse
current limiting. Holding Pin 10 high for a longer duration,
however, will ultimately discharge this external capacitor,
recycling slow turn−on upon release.
Pin 10 should not be left floating as noise pickup could
conceivably interrupt normal operation.
Since both the compensation and soft−start terminals
(Pins 9 and 8) have current source pull−ups, either can
readily accept a pull−down signal which only has to sink a
maximum of 100 A to turn off the outputs. This is subject
to the added requirement of discharging whatever external
capacitance may be attached to these pins.
An alternate approach is the use of the shutdown circuitry
of Pin 10 which has been improved to enhance the available
shutdown options. Activating this circuit by applying a
positive signal on Pin 10 performs two functions: the PWM
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3
SG3525A
ELECTRICAL CHARACTERISTICS (VCC = +20 Vdc, TA = Tlow to Thigh [Note 3], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Reference Output Voltage (TJ = +25°C)
Vref
5.00
5.10
5.20
Vdc
Line Regulation (+8.0 V ≤ VCC ≤ +35 V)
Regline
−
10
20
mV
Load Regulation (0 mA ≤ IL ≤ 20 mA)
Regload
−
20
50
mV
Temperature Stability
Vref/T
−
20
−
mV
Vref
4.95
−
5.25
Vdc
Short Circuit Current (Vref = 0 V, TJ = +25°C)
ISC
−
80
100
mA
Output Noise Voltage (10 Hz ≤ f ≤ 10 kHz, TJ = +25°C)
Vn
−
40
200
Vrms
Long Term Stability (TJ = +125°C) (Note 4)
S
−
20
50
mV/khr
−
±2.0
±6.0
%
REFERENCE SECTION
Total Output Variation Includes Line and Load Regulation over Temperature
OSCILLATOR SECTION (Note 5, unless otherwise noted.)
Initial Accuracy (TJ = +25°C)
Frequency Stability with Voltage
(+8.0 V ≤ VCC ≤ +35 V)
fosc
DVCC
−
±1.0
±2.0
%
Frequency Stability with Temperature
fosc
DT
−
±0.3
−
%
Minimum Frequency (RT = 150 k, CT = 0.2 F)
fmin
−
50
−
Hz
Maximum Frequency (RT = 2.0 k, CT = 1.0 nF)
fmax
400
−
−
kHz
Current Mirror (IRT = 2.0 mA)
1.7
2.0
2.2
mA
Clock Amplitude
3.0
3.5
−
V
Clock Width (TJ = +25°C)
0.3
0.5
1.0
s
Sync Threshold
1.2
2.0
2.8
V
−
1.0
2.5
mA
Sync Input Current (Sync Voltage = +3.5 V)
ERROR AMPLIFIER SECTION (VCM = +5.1 V)
Input Offset Voltage
VIO
−
2.0
10
mV
Input Bias Current
IIB
−
1.0
10
A
Input Offset Current
IIO
−
−
1.0
A
DC Open Loop Gain (RL ≥ 10 M)
AVOL
60
75
−
dB
Low Level Output Voltage
VOL
−
0.2
0.5
V
High Level Output Voltage
VOH
3.8
5.6
−
V
Common Mode Rejection Ratio (+1.5 V ≤ VCM ≤ +5.2 V)
CMRR
60
75
−
dB
Power Supply Rejection Ratio (+8.0 V ≤ VCC ≤ +35 V)
PSRR
50
60
−
dB
Minimum Duty Cycle
DCmin
−
−
0
%
Maximum Duty Cycle
DCmax
45
49
−
%
Input Threshold, Zero Duty Cycle (Note 5)
Vth
0.6
0.9
−
V
Input Threshold, Maximum Duty Cycle (Note 5)
Vth
−
3.3
3.6
V
Input Bias Current
IIB
−
0.05
1.0
A
PWM COMPARATOR SECTION
3. Tlow = 0°
Thigh = +70°C
4. Since long term stability cannot be measured on each device before shipment, this specification is an engineering estimate of average
stability from lot to lot.
5. Tested at fosc = 40 kHz (RT = 3.6 k, CT = 0.01 F, RD = 0 ).
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4
SG3525A
ELECTRICAL CHARACTERISTICS (continued)
Characteristics
Symbol
Min
Typ
Max
Unit
Soft−Start Current (Vshutdown = 0 V)
25
50
80
A
Soft−Start Voltage (Vshutdown = 2.0 V)
−
0.4
0.6
V
Shutdown Input Current (Vshutdown = 2.5 V)
−
0.4
1.0
mA
−
−
0.2
1.0
0.4
2.0
18
17
19
18
−
−
7.0
8.0
V
SOFT−START SECTION
OUTPUT DRIVERS (Each Output, VCC = +20 V)
Output Low Level
(Isink = 20 mA)
(Isink = 100 mA)
VOL
Output High Level
(Isource = 20 mA)
(Isource = 100 mA)
VOH
Under Voltage Lockout (V8 and V9 = High)
VUL
6.0
V
V
IC(leak)
−
−
200
A
Rise Time (CL = 1.0 nF, TJ = 25°C)
tr
−
100
600
ns
Fall Time (CL = 1.0 nF, TJ = 25°C)
tf
−
50
300
ns
Shutdown Delay (VDS = +3.0 V, CS = 0, TJ = +25°C)
tds
−
0.2
0.5
s
Supply Current (VCC = +35 V)
ICC
−
14
20
mA
Collector Leakage, VC = +35 V (Note 6)
6. Applies to SG3525A only, due to polarity of output pulses.
Vref
16
4
PWM
ADJ.
13
Flip/
Flop
3
O
s
c
i
l
l
a
t
o
r
RT
6
Deadtime
1.5k
7
Ramp
0.009
100
5
Out A
11
A
1.0k, 1.0W
(2)
14
B
0.001
0.1
VC
0.1
Sync
1.0k
VCC
0.1
0.1
Clock
3.0k
15
Reference Regulator
Out B
Comp
10k
1 = VIO
2 = 1(+)
3 = 1(−)
1
2
−
V/I Meter
+
12
PWM
GND
0.01
50A
+
2
1
3
2
5.0F
−
5.0k
E/A
5.0k
+
1
2
3
Softstart
8
1
3
1
2
3
9
10
Vref
2.0k
DUT
Shutdown
Figure 2. Lab Test Fixture
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5
SG3525A
200
R D , DEAD TIME RESISTOR ()
Ω
500
RT, TIMING RESISTOR (k Ω )
100
50
* RD = 0 20
10
5
6
5.0
RD *
RT
7
300
200
100
CT
2.0
0
2.0
5.0 10
20
50
100 200 500 1000 2000 5000 10,000
0.2
0.5
1.0
1
−
50
100 200
2
+
9
CP
RZ
RZ = 20 k
40
20
0
−20
1.0
10
100
1.0 k
10 k
100 k
1.0 M
4.0
3.5
2.5
2.0
1.5
Source Sat, (VC−VOH)
1.0
Sink Sat, (VOL)
0.5
0
0.01
10 M
VCC = +20 V
TJ = +25°C
3.0
f, FREQUENCY (Hz)
0.02 0.03 0.05 0.07 0.1
0.2 0.3
0.5 0.7 1.0
IO, OUTPUT SOURCE OR SINK CURRENT (A)
Figure 5. Error Amplifier Open Loop
Frequency Response
Figure 6. Output Saturation
Characteristics
15
16
VCC
Q5
Q1
Q8
7.4k
Q6
5
3
Sync
7
Discharge
Q2
Q3
Q3
6
12
GND
20
Figure 4. Oscillator Discharge Time versus RD
60
CT
10
Figure 3. Oscillator Charge Time versus RT
80
RT
5.0
DISCHARGE TIME (s)
100
Vref
2.0
CHARGE TIME (s)
V sat , SATURATION VOLTAGE (V)
A VOL, VOLTAGE GAIN (dB)
400
2.0k
Q9
2.0k
Ramp
To PWM
14k
Q11
Q10
25k
5.0pF
Blanking
Q14 To Output
400A
Q4
23k
Q7
1.0k
1.0k
Q12
Q13
3.0k
Inverting
Q1
Input
1
Noninverting
Input
2
200A
250
Q4
Q2
To PWM
Comparator
100A
5.8V 30
9
Compensation
4
OSC Output
Figure 7. Oscillator Schematic
Figure 8. Error Amplifier Schematic
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6
SG3525A
13
VCC
VC
Q7
Q5
Q9
Q10
Q4
5.0k
Vref
11, 14
Q11 Output
Q8
Q6
2.0k
Q1
Q2
5.0k
Clock
10k
Q3
Q6 Omitted
in SG3527A
10k
F/F
PWM
Figure 9. Output Circuit
(1/2 Circuit Shown)
Q1
+Vsupply
To Output Filter
+Vsupply
R1
R1
R2
VC A
13
VC
A
SG3525A
11
GND
Q2
R3
In conventional push−pull bipolar designs, forward base drive is
controlled by R1−R3. Rapid turn−off times for the power devices
are achieved with speed−up capacitors C1 and C2.
For single−ended supplies, the driver outputs are grounded.
The VC terminal is switched to ground by the totem−pole
source transistors on alternate oscillator cycles.
Figure 10. Single−Ended Supply
Figure 11. Push−Pull Configuration
+Vsupply
R1
Q1
11
Q1
14
C1
T1
T1
13
11
VC A
SG3525A
SG3525A
GND B
B
12
12
VC A
T1
Q1
R2
C2
14
14
GND
13
11
SG3525A
B
+Vsupply
C1
13
Q2
GND B
12
12
R1
T2
Q2
14
C2
R2
The low source impedance of the output drivers provides
rapid charging of power FET input capacitance while
minimizing external components.
Low power transformers can be driven directly by the SG3525A.
Automatic reset occurs during deadtime, when both ends of the
primary winding are switched to ground.
Figure 12. Driving Power FETS
Figure 13. Driving Transformers in a
Half−Bridge Configuration
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7
SG3525A
PACKAGE DIMENSIONS
PDIP−16
N SUFFIX
CASE 648−08
ISSUE T
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION L TO CENTER OF LEADS
WHEN FORMED PARALLEL.
4. DIMENSION B DOES NOT INCLUDE
MOLD FLASH.
5. ROUNDED CORNERS OPTIONAL.
−A−
16
9
1
8
B
F
C
L
S
−T−
SEATING
PLANE
K
H
G
D
M
J
16 PL
0.25 (0.010)
M
T A
M
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8
DIM
A
B
C
D
F
G
H
J
K
L
M
S
INCHES
MIN
MAX
0.740 0.770
0.250 0.270
0.145 0.175
0.015 0.021
0.040
0.70
0.100 BSC
0.050 BSC
0.008 0.015
0.110 0.130
0.295 0.305
0
10 0.020 0.040
MILLIMETERS
MIN
MAX
18.80 19.55
6.35
6.85
3.69
4.44
0.39
0.53
1.02
1.77
2.54 BSC
1.27 BSC
0.21
0.38
2.80
3.30
7.50
7.74
0
10 0.51
1.01
SG3525A
PACKAGE DIMENSIONS
SOIC−16L
DW SUFFIX
CASE 751G−03
ISSUE C
A
D
9
h X 45 E
0.25
1
16X
M
14X
e
T A
S
B
S
L
A
0.25
B
B
NOTES:
1. DIMENSIONS ARE IN MILLIMETERS.
2. INTERPRET DIMENSIONS AND TOLERANCES
PER ASME Y14.5M, 1994.
3. DIMENSIONS D AND E DO NOT INLCUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE.
5. DIMENSION B DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 TOTAL IN
EXCESS OF THE B DIMENSION AT MAXIMUM
MATERIAL CONDITION.
MILLIMETERS
DIM MIN
MAX
A
2.35
2.65
A1 0.10
0.25
B
0.35
0.49
C
0.23
0.32
D 10.15 10.45
E
7.40
7.60
e
1.27 BSC
H 10.05 10.55
h
0.25
0.75
L
0.50
0.90
q
0
7
8
A1
H
8X
M
B
M
16
SEATING
PLANE
T
C
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9
SG3525A
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
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associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
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For additional information, please contact your
local Sales Representative.
SG3525A/D