Igbt& Mosfet

IGBT & MOSFET CHARACTERISTICS

STUDY TRAINER (Model No: VPET-202A)

User Manual

Version 1.0

Technical Clarification /Suggestion : ✍ / ☎ Technical Support Division, Vi Microsystems Pvt. Ltd., Plot No :75, Electronics Estate, Perungudi, Chennai - 600 096, INDIA. Ph: 91- 44-2496 1842, 91-44-2496 1852 Mail : [email protected] Web : www.vimicrosystem.com 01 - 13 - 03 - 31

CONTENTS Chapter - 1 INTRODUCTION 1 1.1 Introduction 2 Chapter - 2 ABOUT OUT TRAINER 3 2.1 Pictorial View 4 2.2 Specification 4 2.3 Front Panel View 5 2.4 Front Panel Description 6 2.5 Protection & Precaution 7 Chapter - 3 THEORETICAL CONCEPT 8 3.1 Power MOSFET 9 3.2 Insulated Gate Bipolar Transistor (IGBT) 11 Chapter - 4 EXPERIMENTAL SECTION 13 Exp-1 OUTPUT CHARACTERISTICS OF IGBT 14 Exp-2 TRANSFER CHARACTERISTICS OF IGBT 17 Exp-3 OUTPUT CHARACTERISTICS OF MOSFET 20 Exp-4 TRANSFER CHARACTERISTICS OF MOSFET 23

IGBT & MOSFET CHARACTERISTICS STUDY TRAINER VPET – 202A

Vi Microsystems Pvt. Ltd., [ 1 ]

Chapter - 1

Introduction



1. INTRODUCTION Power electronics deals with the applications of solid-state electronics for the control and conversion of electrical power. Conversion techniques require the switching ON and OFF of power semiconductor device. Power switching devices such as power BJTs, power SCRs, GTOs and other semiconductor devices find increasing applications in a wide range of products. The applications of modern microprocessors in synthesizing the control strategy for gating power devices to meet the conversion specifications are widening the scope of power electronics. Power Electronics are employed in various fields that include rocket propulsion systems, motor control, Electric vehicles, air-conditioners, High Voltage Direct Current (HVDC) transmission systems. Objectives On successful completion of this manual you should be able to: * Understand about the IGBT and MOSFET characteristics * Describe the operation of output and transfer characteristics of IGBT and MOSFET. * Work with our module by yourself. Features of VPET-202A * All necessary points terminated in the front panel. * The module can be used to study the operation of output and transfer characteristics of

both IGBT and MOSFET. * Provision for connecting ammeter and voltmeter. This manual describes the IGBT and MOSFET characteristics.



Chapter - 2

About Our Trainer



2.1 Pictorial View

2.2 Specification 1. Power Input : 230V AC, 50Hz. 2. Input power for switch SW1 : 12V DC 3. Input power for switch SW2 : 30V DC



2.3 FRONT PANEL DIAGRAM



2.4 FRONT PANEL DESCRIPTION POT 1 - To vary Gate-Source voltage for MOSFET & Gate-Emitter voltage for

IGBT from min to max value. POT 2 - To vary Drain-Source voltage for MOSFET & Collector-Emitter

voltage for IGBT from min to max value. P1,P2 - Terminations for Gate Input DC voltage. P3,P4 - Terminations for Drain / Collector Input DC voltage. P4,P5 - Terminals to connect Gate-Source / Gate-Emitter to the DC supply. P12,P13 - Terminals to connect Drain- Source / Collector-Emitter to the DC

supply. P6,P7 - Terminals to connect Gate voltage measuring Voltmeter. P8,P11 - Terminals to connect Drain current / Collector current measuring

Ammeter P9,P10 - Terminals to connect Drain voltage / Collector voltage measuring

Voltmeter. SW1 - POT 1 power supply turn ON switch SW2 - POT 2 power supply turn ON switch POWER ON - Trainer power supply turn ON switch.



2.5 PRECAUTIONS Don't i) Don’t short P1 and P2. ii) Don’t short P14 and P15. iii) Don't Inter change Device terminal whenever doing the experiment. iv) Don't use Ammeter mode of multimeter operation for voltage measurement and

viceversa. v) Don't Interchange Ammeter, Volmeter terminal Do's i) Ensure input power supply +30V, +30V DC. ii) Ensure Devices are in good working condition, for that follow Device testing

procedure. iii) Ensure the potentiometer's are working condition. iv) Ensure the fuse is good condition.



Chapter - 3

Theoretical Concept



3.1 POWER MOSFET A metal - oxide semiconductor field-effect transistor (MOSFET) is a recent device developed by combining the areas of field-effect concept and MOS technology. A power MOSFET has three terminals called drain, source and gate. The circuit symbol of power MOSFETis as shown below. Here arrow indicates the direction of electron flow. A power MOSFET is a unipolar device.

Symbol of MOSFET MOSFET Static Characteristics The static characteristics of power MOSFET are now described briefly. The basic circuit diagram for n-channel power MOSFET is shown below, where voltages and currents are as indicated. Circuit diagram of MOSFET

G

D

S

LOAD

G

D

S

V GS

DS

R

V

V

G

D

VDD

ID

+

-

+

-



i. Transfer Characteristics This characteristics shows the variation of drain current ID as a function of gate source VGS. Figure shows typical transfer characteristics for n-channel power MOSFET. It is seen that there is threshold voltage VGST below which the device is off. The magnitude of VGST is the order of 2 to 3 V.

D

42 6 8V

10

GSTV

Transfer characteristics of MOSFET ii. Output Characteristics Power MOSFET output characteristics shown in Figure indicate the variation of drain current ID as a function drain - source voltage VDS as a parameter. For low values of VDS , the graph between ID - VDS is almost linear. ; this indicates a constant value of on - resistance RDS = VDS / ID . For given VGS, if VDS is increased, output characteristics is relatively flat indicating that drain current is nearly constant.

Output characteristics of MOSFET

Linear Region

)DS(V

VGS1.............>VGS0GSV

GS1V

VGS2

GS3V

VGS4

GS5V

VGS6

GS7V

DRAIN SOURCE VOLTAGE



3.2 INSULATED GATE BIPOLAR TRANSISTOR (IGBT) IGBT is a new development in the area of power MOSFET technology. This device combines into it the advantage of both MOSFET and BJT. So an IGBT has high input impedance like a MOSFET and low-on-state power loss as in a BJT. Further, IGBT is free from second breakdown problem present in BJT. IGBT is also known as metal-oxide insulated gate transistor conductively - modulated field effect transistor (COMFET) or gain - modulated FET (GEMFET). It was also initially called insulated gate transistor (IGT). IGBT Characteristics The circuit of Fig shows the various parameters pertaining to IGBT characteristics. Static V - I or output characteristics of an IGBT (n-channel type) show the plot of collector current IC versus collector emitter voltage VCE for various values of gate- emitter voltages. These characteristics are shown in Fig. In the forward direction, the shape of the output characteristics is similar to that of BJT. But here the controlling parameter is gate-emitter voltage VGE because IGBT is a voltage controlled device. Circuit diagram of IGBT The transfer characteristic of an IGBT is a plot of collector current IC versus gate-emitter voltage VGE as shown in Fig. This characteristic is identical to that of power MOSFET. When VGE is less than the threshold voltage VGET, IGBT is in the off-state.

+

-

R s

RGE V GE

E

C

Ic

CCV

CEV

G

+

-

R

REGV



VGEGETV

cI(A)

Transfer characteristics of IGBT

Ic(A)

VGE4> GE5V etc..

GE5V

GE4V

VGE3

GE2V

GE1V

VCE0

VRM

Output Characteristics of IGBT When the device is off, junction J2 blocks forward voltage and in case reverse voltage appears across collector and emitter, junction J1 blocks it.



Chapter - 4

Experimental Section



EXPERIMENT - 1 OUTPUT CHARACTERISTICS OF IGBT AIM To study the output characteristics of IGBT by using VPET-202A module. EQUIPMENT REQUIRED 1. VPET - 202A module. 2. Voltmeter (0-30V) 3. Ammeter (0-200mA) 4. Patch chords CONNECTION PROCEDURE 1. Connect the banana connectors P1 to P4, P2 to P5, P12 to P14 and P13 to P15. 2. Ammeter is connected across the banana connector P8 and P11. 3. Voltmeter(VGE)is connected across the banana connector P6 and P7. 4. Voltmeter (VCE) is connected across the banana connector P9 and P10. 5. Connect the Connector P17 to P6. 6. Connect the Connector P19 to P10. 7. Connect the Connector P18 to P8. EXPERIMENT PROCEDURE 1. Verify the connection as per the connection procedure. 2. Switch ON the power supply. 3. Switch ON the power ON/OFF switch. 4. Switch ON the switch SW1 and SW2. 5. Set the Gate-Emitter (VGE) voltage at particular voltage by varying POT1. 6. Smoothly vary the (POT2) Collector -Emitter (VCE) voltage till the IGBT get turn

on and note down the voltmeter (VCE) and Ammeter (IC) values in the table 1.



7. Further increase the collector-Emitter (VCE) voltage and note down the readings VCE and IC in the table 1.

8. Note the Collector current (Ic) for different values of Gate-Emitter voltage (VGE) in

the table1. 9. Note down the pinch-off voltage, from the graph sheet. TABLE:1

S.No VGE = V

VCE (V) IC(mA)

Note: Voltage and Current value depends upon temperature. MODEL GRAPH

Ic(A)

VGE4> GE5V etc..

GE5V

GE4V

VGE3

GE2V

GE1V

VCE0

VRM



CONNECTION DIAGRAM FOR IGBT RESULT Thus the output characteristics of IGBT was studied and the graph was plotted.



EXPERIMENT - 2 TRANSFER CHARACTERISTICS OF IGBT AIM To Study the Transfer characteristics of IGBT by using VPET-202A Module. EQUIPMENT REQUIRED 1. VPET-202A Module. 2. Voltmeter (0-30V) . 3. Ammeter (0-200 mA) 4. Patch chords PROCEDURE 1. Connect the banana connectors P1 to P4, P2 to P5, P12 to P14 and P13 to P15. 2. Ammeter is connected across the banana connector P8 and P11. 3. Voltmeter(VGE)is connected across the banana connector P6 and P7. 4. Voltmeter (VCE) is connected across the banana connector P9 AND P10. 5. Connect the Connector P17 to P6. 6. Connect the Connector P19 to P10. 7. Connect the Connector P18 to P8. EXPERIMENT PROCEDURE 1. Verify the connection as per the connection procedure. 2. Switch ON the power supply. 3. Switch ON the power ON/OFF switch. 4. Switch ON the switch SW1 and SW2. 5. Keep the Collector-Emitter (VCE) voltage at particular voltage by varying POT2 6. Smoothly vary the (POT1) Gate-Emitter voltage (VGE) till the IGBT gets turn on and

note down voltmeter (VGE) and Ammeter (IC) values in the table 2.

7. Note down the Collector Current (IC) for different values of Collector-Emitter voltage (VCE) in the table2.



TABLE:2

S.No VCE =

VGE(V) Ic mA

MODEL GRAPH

VGEGETV

cI(A)



CONNECTION DIAGRAM

RESULT Thus the transfer characteristics of IGBT was studied and the graph was plotted.



EXPERIMENT - 3 OUTPUT CHARACTERISTICS OF MOSFET AIM To study the output characteristics of MOSFET by using VPET-202A module. EQUIPMENT REQUIRED 1. VPET - 202A module. 2. Voltmeter (0-30V). 3. Ammeter (0-200 mA) 4. Patch chords CONNECTION PROCEDURE 1. Connect the banana connectors P1 to P4, P2 to P5, P12 to P14 and P13 to P15. 2. Ammeter is connected across the banana connector P8 and P11. 3. Voltmeter(VGS) is connected across the banana connector P6 and P7. 4. Voltmeter (VDS) is connected across the banana connector P9 and P10. 5. Connect the Connector P20 to P6. 6. Connect the Connector P22 to P10. 7. Connect the Connector P21 to P8. EXPERIMENT PROCEDURE 1. Verify the connection as per the connection procedure. 2. Switch ON the power supply. 3. Switch ON the power ON/OFF switch. 4. Switch ON the switch SW1 and SW2. 5. Set the Gate-Source (VGS) voltage at particular value by varying POT1. 6. Smoothly vary the (POT2), Drain-Source (VDS) voltage till the MOSFET gets turn

on and note down the voltmeter (VDS) and Ammeter (ID) values in the table 3. 7. Further increase the drain-source (VDS) voltage and note down the readings VDS and

ID in the table 3. 8. Note down the pinch-off voltage, from the graph sheet.



TABLE:3

S.No VGS = V

VDS (V) ID(mA)

Note: Voltage and Current values depends upon temperature MODEL GRAPH

Output characteristics of MOSFET

Linear Region

D

)DS(V

VGS1.............>VGS0GSV

GS1V

VGS2

GS3V

VGS4

GS5V

VGS6

GS7V

DRAIN SOURCE VOLTAGE

DRA

IN C

UR

REN

T (I

)



CONNECTION DIAGRAM RESULT Thus the output characteristics of MOSFET was studied and the graph was plotted.



EXPERIMENT - 4 TRANSFER CHARACTERISTICS OF MOSFET AIM To Study the Transfer characteristics of MOSFET by using VPET-202A Module. EQUIPMENT REQUIRED 1. VPET-202A Module. 2. Voltmeter (0-30 V) 3. Ammeter (0-200 mA) 4. Patch chords CONNECTION PROCEDURE 1. Connect the banana connectors P1 to P4, P2 to P5, P12 to P14 and P13 to P15. 2. Ammeter is connected across the banana connector P8 and P11. 3. Voltmeter(VGS) is connected across the banana connector P6 and P7. 4. Voltmeter (VDS) is connected across the banana connector P9 and P10. 5. Connect the Connector P20 to P6. 6. Connect the Connector P22 to P10. 7. Connect the Connector P21 to P8. EXPERIMENT PROCEDURE 1. Verify the connection as per the connection procedure. 2. Switch ON the power supply. 3. Switch ON the power ON/OFF switch. 4. Switch ON the switch SW1 and SW2. 5. Set the Gate-Source (VGS) voltage at particular value by varying POT2. 6. Smoothly vary the (POT1), Drain-Source (VDS) voltage till the MOSFET gets turn

on and note down the voltmeter (VDS) and Ammeter (ID) values in the table 3. 7. Further increase the drain-source (VDS) voltage and note down the readings VDS and

ID in the table 3. 8. Note down the pinch-off voltage, from the graph sheet.



TABLE:4

S.No VD S =

VGS(V) ID mA

MODEL GRAPH

D

42 6 8V

10

GSTV

Transfer characteristics of MOSFET



CONNECTION DIAGRAM RESULT Thus the transfer characteristics of MOSFET was studied and the graph was plotted.



4.3 SERVICE TIPS 1. Follow the Device testing procedure to checkout the Device working condition. FOR IGBT

G

i) Made multimeter as Diode mode of operation. ii) Connect multimeter +ve terminal to Emitter Terminal of IGBT iii) Connect Multimeter -ve terminal to Collector Terminal of IGBT iv) Now multimeter will show the Diode internal Resistance. v) Remaining Any of two combination will show open value. FOR MOSFET

i) Made multimeter as Diode mode of operation. ii) Connect multimeter +ve terminal to source terminal of MOSFET iii) Connect Multimeter -ve terminal to Drain terminal of MOSFET iv) Now multimeter will show the Diode internal Resistance. v) Remaining Any of two combination will show open value. 2. Check out the power supply voltage if it is not multi o/p power supply may be fault. 3. Check out continuity of potentiometer using multimeter. If it is not potentiometer

may be fault.

G

D

S

Igbt& Mosfet

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