Post on 08-Apr-2018
8/7/2019 Discretes Semiconductors
1/54
8/7/2019 Discretes Semiconductors
2/54
IntroductionIntroduction This training material contains Basic information
about Discrete Semiconductors and how they areused.
It is simplified for use such that a technicalbackground is not required for understanding.You will learn specifically about Types of
Discrete Semiconductors. Information will enable you to properly identify
and categorize types of Discrete semiconductorsbased on product characteristics.
8/7/2019 Discretes Semiconductors
3/54
Topics CoveredTopics Covered
1. Introduction to Semiconductors
2. Discrete Semiconductors
3. Integrated Circuits
4. Packaging
5. Glossary of Terms
6. Self-test
8/7/2019 Discretes Semiconductors
4/54
Course OutlineCourse Outline
PART ONE 2hrs
Introduction to Semiconductors
Discrete Semiconductors
PART TWO 2 hrs
Integrated Circuits
PART THREE 2 hrs
Packaging
Glossary of Terms
Self-test
8/7/2019 Discretes Semiconductors
5/54
PART ONEPART ONE
Introduction to Semiconductors
Discrete Semiconductors
8/7/2019 Discretes Semiconductors
6/54
1. Introduction to Semiconductors1. Introduction to Semiconductors
1.1 What are semiconductors?
1.2 How are semiconductors made?
1.3 What do semiconductors do?
1.4 Who makes semiconductors?
1.5 Who buys semiconductors?
1.6 Types of Semiconductors
8/7/2019 Discretes Semiconductors
7/54
1.1 What are Semiconductors?1.1 What are Semiconductors?
Materials with conductivity between conductorand insulator.
Conductor Semiconductor Insulator
Copper Silicon Plastics
Aluminum Germanium Rubber
Gold Gallium Arsenide Ceramics
8/7/2019 Discretes Semiconductors
8/54
8/7/2019 Discretes Semiconductors
9/54
8/7/2019 Discretes Semiconductors
10/54
First transistor made by Schockley, Brattain & Bardeen in 1947
First transistor was made in 1947First transistor was made in 1947
8/7/2019 Discretes Semiconductors
11/54
1.2 How are semiconductors made?1.2 How are semiconductors made?
SandCrystal
Growth
Ingot
Slicing
Wafer
Polish
DiffusionPhoto/
EtchDoping
Metal/
Test
Wafer
SawPackaging Final Test
8/7/2019 Discretes Semiconductors
12/54
1.3 What do Semiconductors do?1.3 What do Semiconductors do?
SensingInput
Isolation&
Protection
WorkOutput
Power
DecisionMaking
LogicSmall Signal
ZenersRectifiers
LogicAnalog
ZenersRectifiers
PowerTransistorsRectifiersThyristors
IGBTs
AnalogRectifiers
Power Transistors
Isolation&
Protection
They perform many functions in every electronic system
8/7/2019 Discretes Semiconductors
13/54
SIM/SAM Smart-card interfaceMC33560
NCN6000*NCN6010*NCN6011*
RF Power Amplifier
Control & Supply,Op. Amps
MC33170MC33202MC33501
BatteryManagementMC33349MC33340/2
O Voltage Regulationulti-Output, Inductive load78LC/FC/PCxx MC3326333275/375 MC3376533283 MC33761 MC33762
nergy Conversion
ase-band SupplyCD BiasC33463 MC33466C34280 MC7660AX828/9 MC1121
Voltage SupervisoryNCP300/1/2/3/4/5
NCP345MAX809/810
I/O ProtectionNCP345
For Example
8/7/2019 Discretes Semiconductors
14/54
Applications For Semiconcuctor Products
Automotive Personal Digital Assistant Printer Control BoardABS & Traction Control Audio DC-DCCar radio Backlight control ESD/Transient ProtectionConvenience control Interface ON/OFF Control
DC Motor Control & H-bridge LED Drivers SensorsEngine Management Li-ion Charge control Stepping Motor DriversIgnition System Li-ion/Ni-MH DC-DC Converters USB InterfaceLIN Transceiver Li-ion/Ni-MH LDOsMotor Fan ON/OFF Control Settop Box
PA Control Clock DistributionDesktop Computers USB Interface Clock GenerationGraphics Card Voltage Supervisory General Purpose LogicPower Delivery PLL
Silver Box Power Supplies SAM/SIM InterfaceUSB Interface High Watt (>100W) USB Interface
Low Watt (
8/7/2019 Discretes Semiconductors
15/54
Application: Cellular Phones
Average: 10 to 70 components in theAverage: 10 to 70 components in the
typical cell phonetypical cell phone
8/7/2019 Discretes Semiconductors
16/54
1.4 Who makes Semiconductors?1.4 Who makes Semiconductors?
FairchildIntegrated Device Tech
VLSI TechMaximCirrus LogicATI TechAltera
QualcommHarrisXilinxOkiHPAtmelConexantAnalog Devices
LG SemiconSonyHyundaiLSI LogicRohmMicron TechSharpSanyoNationalMatsushitaAMD
IBMLucent
MitsubishiFujitsuSiemens
STMPhilipsHitachiSamsung
ToshibaTI
MotorolaNEC
Intel
ON Semiconductor
RelativeSharePosition
Top 40 Semiconductor suppliers in 1999
8/7/2019 Discretes Semiconductors
17/54
1.51.5 Who buys Semiconductors?Who buys Semiconductors?
OEMs Original equipment manufacturers. Such as IBM, Apple, Dell,
Ford, Chrysler, Nokia, Motorola etc.
Distributors For Resale to low volume users. Eg Arrow, Avnet, etc
EMSIs Contract Manufacturers who build equipment for the OEMs.
Eg Selectron etc.Individuals For personal use
EMSIs9%
Distributors45%
45%
9%
46
OEMs46%
Typical Semiconductor CoRevenue By Customer
8/7/2019 Discretes Semiconductors
18/54
1.6 Types of Semiconductors1.6 Types of Semiconductors
Discrete Semiconductors
These are devices that perform a single function such asswitching, rectification or amplification. Examples are
diodes, transistors and thyristors
Integrated Circuits
These are combination of discrete elements on a single pieceof silicon performing single or multiple functions such asvoltage regulation, synchronous rectification, storage ofinformation in memory, high speed switching or powermanagement. Examples are analog switches, logic gates,operational amplifiers and LDO voltage regulators.
8/7/2019 Discretes Semiconductors
19/54
Worldwide SemiconductorMarket
Product Breakdown (1999)
Source: WSTS
Total Semiconductors - $149.4B
Integrated Circuits - $130.2B
Digital - $108.1B
MOS - $107.1B
Memory
$32.3B
DRAM$20.7B
Discrete&Opto$19.2B
Analog$22.1B
Diodes,Rectifiers.Transistors,etc.$13.3B
Optoelectronics - $5.8B
Amp.,Interface,etc.$16.2B
SpecCons$5.9B
Digital Bipolar - $1.0BLogic
$23.2BMicro - $51.7B
SRAM $4.7B
Non-volatileMemory:ROMsEPROMEEPROM
$2.0B
Microproc-
essor -
$27.2B
Micro-
control-
ler
$14.1B
Micro-
peri-
pheral
$10.4B
DSP $4.4B
OtherLogic
$10.5B
ASIC
Gate Arrays,FPL Standardcells
$12.7B
Flash $4.6B
MixedSignal
Flash $4.6B
8/7/2019 Discretes Semiconductors
20/54
2.2. Discrete SemiconductorsDiscrete Semiconductors
2.1 Diodes2.1.1 Small signal diodes
2.1.2 Rectifiers
2.1.3 Zener
2.1.4 TVS
2.2 Transistors2.2.1 Small Signal Bipolar Transistors
2.2.2 Bipolar Power Transistors
2.2.3 Field Effect Transistors (FET)
2.3 Mosfets
2.3.1 Mosfet Operation2.3.2 Small Signal & Power Mosfets
2.3.3 SmartDiscrete
2.4 IGBT
2.5 Thyristors
8/7/2019 Discretes Semiconductors
21/54
Common terminologyCommon terminology
Name Symbol Simple meaning (Units)Current I Movement of electrons. (Amperes, A)
Voltage V Potential that causes current to flow (Volts, V)
Power P Current X Voltage. Total Force applied (Watts, W)Resistance R Resistance to current flow. (Ohms)
8/7/2019 Discretes Semiconductors
22/54
2.12.1 DiodesDiodesA diode consists of a PN junction and has
two(2) terminals, an anode(+) and a
cathode(-). Current flows in only one
direction: from anode to cathode within the
diode.
An ideal diode is like a light switch inyour home. When the switch is closed,
the circuit is completed; and the light
turns on. When the switch is open, there
is no current and the light is off.
Anode (+)
Cathode (-)
(+)(-)
8/7/2019 Discretes Semiconductors
23/54
2.12.1 Diode CharacteristicsDiode Characteristics
Important diode specifications are:
(a) Reverse voltage, Vr
(b) Rated forward current, If
(c) Forward voltage drop, Vf
(d) Leakage current, Ir
(e) Package style
(f) Reverse recovery time, trrVf
Generally, Diodes are used in waveshaping(rectification) applications. This involves
the alteration of AC signals by passing
certain portions of the signal and blocking
the rest.
8/7/2019 Discretes Semiconductors
24/54
2.1.12.1.1 Small Signal DiodesSmall Signal Diodes
These are diodes which are rated to handle less than 1W of Power.
Power >1W can destroy these diodes.
There are Schottky, switching and Tuning diodes with differentcharacteristics which define their special functions.
Schottky diodes have very low forward drop (Vf) and are used in highspeed switching applications.
Switching diodes are used in general purpose switching applications
Tuning diodes are used for FM radio, TV Tuning and high frequencycontrol applications
8/7/2019 Discretes Semiconductors
25/54
Small Signal Diode CharacteristicsSmall Signal Diode Characteristics
Schottky
Diode
Switching
Diode
Tuning
Diode
Max PowerRating (W)
1 1 1
Special
Characteristics
Low forwarddrop (Vf)
General purpose SensitiveCapacitance-
voltage response(High Q)
Typical use High speedswitching
General purposeswitching
FM Radio & TVTuning
8/7/2019 Discretes Semiconductors
26/54
2.1.22.1.2 RectifiersRectifiers
These are diodes which are rated to handle very high Power. Some of these
diodes can handle up to 1000W or more.
Schottky rectifiers handle high current and moderate voltage and can switch
very fast efficiently. Silicon Bipolar rectifiers (standard & fast recovery) can
handle high voltage and moderate current but switch slower. They can be madeto switch faster (Ultrafast and Ultrasoft) but will also have reduced conduction
efficiency.
Rectifiers convert AC signals to DC and vice-versa by process called
rectification. They are generally used in Power supplies, high frequency
switching applications including motor speed control and for circuit protection.
8/7/2019 Discretes Semiconductors
27/54
Rectifier CharacteristicsRectifier Characteristics
Rectifiers
Schottky Std Recovery FastRecovery
Ultrafast Ultrasoft
Power Rating (W) Up to 1000High I,
Low V
Up to 1000
High V,
Low I
Up to 1000
High V,
Low I
Up to 1000
High V, Low I
Up to 1000
High V,
Low I
SpecialCharacteristics
Low Vf & fastswitching
ModerateRecovery speed
(trr)
Fast Recoveryspeed (trr)
Very Fast
Recoveryspeed (trr)
Very fast andcontrolled
Recovery (Qrr)
Typical Use Low Voltagehigh freq
rectification
General Purpose DC Powersupply,
Ultrasonic &low RF systems
High VoltageHigh Freq
rectification
PFC, Variablespeed motor
contol
8/7/2019 Discretes Semiconductors
28/54
2.1.3 Zener Diode2.1.3 Zener Diode
Zener diodes are designed to have a specific reverse breakdown voltage bycareful doping of the junction
The Zener acts as a voltage regulator by operating under reverse bias
conditions Any voltage higher than the reverse breakdown, Vz, isdissipated across the junction.
The zener can recover from reverse breakdown as long as the maximumPower rating is not exceeded.
Low Power (1W) zeners are available in radial or axial leads while medium(10W) and high power (20W) are usually in metal cases for attachment toheat sinks.
8/7/2019 Discretes Semiconductors
29/54
2.1.4 TVS Diodes2.1.4 TVS Diodes (Transient Voltage Suppressor)(Transient Voltage Suppressor)
A TVS Diode limits over voltages caused by current surges and dissipates high transientpower with very short response times
(1 pico sec).
Unidirectional
Bi-directional
D.C. Current Protection
A.C. Current Protection
Additional important specifications are:
(a) Vcl; max protection voltage
(b) Ipp; Peak pulse current
(c) Ppp; Peak pulse power (Ipp x Vcl)
(d) Tcl; Time to avalanche
(e) Ifsm: Rated Forward pulse current
8/7/2019 Discretes Semiconductors
30/54
2.22.2 TransistorsTransistors
The transistor is an arrangement of Semiconductor materials that share commonphysical boundaries. In n-type silicon, impurities, called dopants are introduced
resulting in excess of electrons or negative charges. In p-type silicon the dopants
lead to a deficiency of electrons and therefore an excess of positive charge carriers
or holes. When electric potential on the n or p sections are properly set, current
flow can be turned ON or OFF and signals can be magnified or changed.
The Junction Transisor The Field Effect Transistor The metal-oxide FET
(Bipolar Transistor) (JFET)
PPN N
Emitter
Base
Collector
Gate 1
Gate 2
P
P
NSource Drain
Source
P
N N
DrainGateNPN
8/7/2019 Discretes Semiconductors
31/54
2.2.1 Small Signal Bipolar Transistors2.2.1 Small Signal Bipolar Transistors
Small Signal Bipolar
Transistors are NPN or
PNP transistors which
have max power rating
Of 1 Watt or less.
In contrast, Bipolar
Power transistors can
handle considerablymore power.
8/7/2019 Discretes Semiconductors
32/54
Small Signal Bipolar Transistors-TypesSmall Signal Bipolar Transistors-Types
GeneralPurpose
Switching BRT Darlington RadioFrequency
Characteristic Wide range Fast switchingwith low losses
Built-in resistornetwork
Cascade of twoor moretransistorsconnected to
increase currentgain
High Frequencyoperation withhigh Ft
Typical Use Signalamplification
Amplification &switching
Save boardspace. No needfor externalresistor
Power Supplieswhere highcurrent gain isrequired
VHF/UHF signalamplification.TV/Radio
8/7/2019 Discretes Semiconductors
33/54
NPN Bipolar Transistor BiasingNPN Bipolar Transistor Biasing
Fwd biased Junction Reverse biased Junction
8/7/2019 Discretes Semiconductors
34/54
NPN Transistor OperationNPN Transistor Operation
The P-type base is set betweenthe N-type emitter and collector
There are two P-N junctions thatcan communicate
Base-emitter junction is forwardbiased and base-collectorjunction is reverse biased.
Electrons are injected from theemitter into the base, diffuse tothe base-collector junction andfall down the steep hill into thecollector.
In the base region, some of theelectrons recombine with holes inthis p-type region
8/7/2019 Discretes Semiconductors
35/54
Amplification in NPN TransistorAmplification in NPN Transistor
The emitter current, (Ie) represents 100% of thecurrent flow in the transistor.
Only 2-5% of the current flow is base current (Ib)
The remaining 95-97% is collector current (Ic)
Ie = Ib + Ic
The amount of current leaving the emitter is only
a function of the small emitter-base bias (Vbb)
A small change in the emitter-base bias causes
a large change in the collector current since mostof the emitter current ends up in the collector.
This is the principle of AMPLIFICATION.
8/7/2019 Discretes Semiconductors
36/54
NPN Transistor AmplificationNPN Transistor Amplification
Important parameters: Current Gain or Beta, hfe = Change in Ic/Change in Ib
Transconductance, gm = Change in Ic/Change in V
I
vbe
Q-point
time
time
Vbe
cI
Input Signal
Output Signal
8/7/2019 Discretes Semiconductors
37/54
2.2.22.2.2 Bipolar Power TransistorBipolar Power Transistor
Bipolar Power transistors differ from smallsignal Bipolar transistors in that they can
handle more power.They are used in high power audio
amplification as high frequency drivers orgeneral purpose switching in regulators,
converters and power amplifiers
8/7/2019 Discretes Semiconductors
38/54
Small Signal vs Power Bipolar TransistorSmall Signal vs Power Bipolar Transistor
Small Signal
Bipolar transistor
Power Bipolartransistor
Ptmax (W)< 1 1.25 - 300
Ic (Amp) 0.05 3 0.3 - 60
Vceo (Volt) 5 - 450 25 - 500
Hfe min 15 500 5 - 3000
Hfe max 45 - 1500 25 - 20000
Ft min (MHZ) 15 - 450 .08 - 65
8/7/2019 Discretes Semiconductors
39/54
8/7/2019 Discretes Semiconductors
40/54
JFET OperationJFET Operation
Drain to source Voltage (Vds) changes the resistance in the channel by reducing the channel size
(depletion) which in turn reduces the amount of current flow. As the Vds increases, it reaches a
point, where the channel is closed off and current flow stops. Gate to source voltage (Vgs)
has the same effect and so the channel can be closed from both Vds and Vgs
8/7/2019 Discretes Semiconductors
41/54
JFET OperationJFET Operation
Important Parameters:
Idss The value of drain current, IDwhich flows when Vgs = 0v
Vp - The Pinchoff Voltage. This is the value of Vds at which increase in the Vds does not
produce an increase in ID.. When Vgs is increased, the Vp value is reached sooner as the Vgs
adds to the drain-to-source value pinching off the channel faster.
JFETs are used in audio and RF amplification and for high frequency switching functions.
8/7/2019 Discretes Semiconductors
42/54
JFET ParametersJFET Parameters
Parameter Typical Values
IDSS (uA) 1000-150000
VBR(DSS) (V) 25-40
Ciss (pF) 4 85
Crss (pF) 1 - 15
8/7/2019 Discretes Semiconductors
43/54
2.3 Mosfets2.3 MosfetsMosfets are metal-oxide semiconductor Field effect Transistors
Source
Gate
Drain
N
PP
A Mosfet is a sophisticated,
Solid-state ON/OFF switch.
Low Voltage, Low rdson Mosfets
are used extensively for
Power management in Portable &
Battery powered products (Computers,
Printers, Cellular Phones).
They are also used in low voltage,
high speed switching
applications in Power supplies,
Converters and motor controls.
8/7/2019 Discretes Semiconductors
44/54
2.3.1 Mosfet Operation2.3.1 Mosfet OperationWhen the gate of the Mosfet is open by the
appropriate gate voltage, Vgs, current, IDflows from source to drain as shown.
The Gate Voltage required to turn the
Mosfet ON is called the Threshold
Voltage (Vth).
If the threshold voltage is not reached, the
Mosfet remains in the OFF state. In this
way, a Mosfet is a simple ON/OFF switch,
just like the light switch in your house.
The amount of resistance to current flow in
the ON state is called Rds(on).
The Mosfet blocks any applied drain-to-
source voltage, until the rated VBDSSwhen appreciable drain-to-source current,
IDSS flows.
Gate
N
PP
Drain
Source
Current Flow ID
8/7/2019 Discretes Semiconductors
45/54
2.3.2 Small Signal & Power Mosfets2.3.2 Small Signal & Power Mosfets
Small Signal Mosfet Power Mosfet
VBDSS (Volts) 8 - 240 8 - 200
Rds(on) (mohm) 160 14000 4.6 - 1000
IDmax (Amps) .115 - 2 0.9 - 110
PD max (Watts) .15 1.5 0.4 - 300
Power Mosfet Rds(on) is a very important parameter and has been continouslyreduced as the Technology has improved. This parameter determines how muchresistance exists to current flow. Low rdson is good because it minimizes the needfor expensive heat sinks.
8/7/2019 Discretes Semiconductors
46/54
2.3.32.3.3 SmartDiscretesSmartDiscretes
A SmartDiscrete is a discrete device with some added intelligence.These devices can perform additional functions including sensing ofoverstress conditions and reacting to protect themselves or othercircuit elements around them.
The smart features are built into the device during fabrication byusing simple methods to fabricate these additional elements made ofdiodes, zeners and resistors.
Examples of these features are current limiting function, thermalshutdown, short circuit protection, overvoltage protection, automaticrestart and temperature sensing.
8/7/2019 Discretes Semiconductors
47/54
8/7/2019 Discretes Semiconductors
48/54
2.42.4 IGBT IGBT Insulated Gate Bipolar TransistorInsulated Gate Bipolar Transistor
The structure is very similar to that of a vertically diffused MOSFET featuring a double diffusion
of a p-type region and an n-type region. An inversion layer can be formed under the gate by
applying the correct voltage to the gate contact as with a MOSFET. The main difference is the use
of a p+ substrate layer for the drain. The effect is to change this into a bipolar device as this p-type
region injects holes into the n-type drift region.
8/7/2019 Discretes Semiconductors
49/54
IGBT CharacteristicsIGBT Characteristics
An IGBT combines the simple gate drive of the Mosfet with
the high current carrying capability of a bipolar transistor.
IGBTs are specially suited for high Voltage and high currentswitching.
8/7/2019 Discretes Semiconductors
50/54
2.52.5 ThyristorsThyristors
A Thyristor or S.C.R. (siliconcontrolled rectifier) is a devicethat can supply large currents orswitch large currents ON or OFF.
Thyristors are specified by thereverse voltage, the gate voltageand current.
A Thyristor acts like a diodepassing current in one directiononly.
8/7/2019 Discretes Semiconductors
51/54
Thyristor OperationThyristor Operation
The thyristor acts as a diode, passing current in one direction only. Thevoltage at the gate controls the flow of current between the anode and the
cathode. When a momentary positive voltage of approximately 2 volts isapplied to the gate, a large current will flow from anode to cathode evenif the voltage at the gate is removed. The thyristor can be turned off byInterrupting the power supply. This can be done using a switch in the +vepower supply rail or bypassing the thyristor anode to cathode with aswitch. Gate current is limited by the use of a series resistor. The thyristoralso needs a load resistor otherwise it may be damaged.
8/7/2019 Discretes Semiconductors
52/54
Thyristor ParametersThyristor Parameters
Parameter Typical Values
On-state Current, IT 0.8 25 A
Peak off-state Voltage, VDRM 30 - 800 V
Peak Surge Current, ITSM 8 - 300 A
Gate Trigger Current, IGT 0.075 30 mA
8/7/2019 Discretes Semiconductors
53/54
What you should knowWhat you should know
You have learnt the basic differences betweendiodes, transistors, Mosfets, Igbt and Thyristors.Consider these as the family names.
You should be able to identify a device andclassify it correctly to its family.
You should remember the different memberswithin each device family.
You should also know some importantcharacteristics about each family and its members.
8/7/2019 Discretes Semiconductors
54/54
How to use this informationHow to use this information
You now have a general background tounderstand the different devices in the
Semiconductor Discrete PortfolioYou should use this material as a reference