overview of power semiconductor...

Overview of Power Semiconductor Devices

NCTU 2005 Power Electronics Course Notes

page 1


Filenam e: \A15 投影片：功率元件\PD-01.功率半導體元件簡介.ppt

2005年3月1日

鄒應嶼教授

國立交通大學電機與控制工程研究所

國立交通大學電力電子晶片設計與DSP控制實驗室Power Elect ronics IC Design & DSP Cont rol Lab., NCTU, Taiwan

http://powerlab.cn.nctu.edu.tw/

POWERLABNCTU

電力電子晶片設計與DSP控制實驗室Power Elec tronics I C Des ign & DSP Control La b.

台灣新竹交通大學 • 電機與控制工程研究所

page 2

Contents

Ideal Power Switching DeviceClassification of Power Semiconductor DevicesPower DiodeThyristorGTOBipolar Power TransistorPower MOSFETIGBT/IPMMCT/ICGT/IEGT/GCT

page 3

Power Semiconductor Devices

page 4

Generic Controllable Switch

The ideal controllable switch has the following characteristics:1. Infinite blocking voltage and zero leakage current2. Infinite conducting current and zero conducting resistance3. Zero turn-on and turn-off time4. Zero switching loss5. No triggering power

iT+

−

vT

page 5

Generic-Switch Switching Characteristics (linearized)

(a) simplif ied clamped-inductive-switching circuit, (b) switch wavef orms, (c) instantaneous switch power loss.

+−

Vd

+

−

vT

iT

ideal Io

Vd

0

0

0

t

t

t

Off Off

On

Switch c ontr ol si gnal

ton

ss f

T 1=toff

IoVd

vT . iT

Von

td(off) trv tfitc(off)

tri tfv

tc(on)td(on)pT(t)

VdIo

Won

)(21

oncod(on)c tIVW = )(21

offcod(off)c tIVW =

page 6

Classification of Power Semiconductor Devices

Diodes: On and off states controlled by the power circuit.

Thyristors: Latched on by a control signal but must be turned off by the power circuit.

Controllable switches: Turned on and off by control signals.



page 7

Diode

(a) symbol (b) i-v characteristics (c) idealized characteristics

A K

iD

vD+ −

iD

vD vD

iD

VratedVF(I)

I

0

Reverseblockingregion

0

page 8

Diode Turn-Off

iD

0 t

IRM

trr

Qrr

reverse-recovery time

At turn-on, the diode can be considered an ideal sw itch.

How ever, at turn-off, the diode current reverses for a reverse-recovery time trr. of a diode

page 9

Types of Diodes

Schottky Diodes:Low forward voltage drop (typically 0.3 V)Limited blocking voltage (50-100 V)

Fast-Recovery Switching Diodes:Short reverse-recovery timeSeveral nano seconds for low ratings and less than a few micro seconds for high ratings of several hundred volts and several hundred amperes.

Line-Frequency Diodes:Low on resistanceLarge reverse-recovery timeSuit for low-frequency applicationsVery high voltage and current ratings

page 10

Comparison of Rectifier Characteristics

Typical characteristics of various types of diode

Diode technology VF (V) Trr (ns) VR(max) Relative cost

Fast recoveryUltrafast recoverySchottky

1.2-1.40.9-1.00.2-0.6

15025-80



page 13

Volt-Ampere Characteristics of Thyristor

Forward conduction

Forward breakovervoltage

Forward leakage

Reverseleakage

Av alanchebreakdown

Holding current

-VA +VA

IG=0IG1IG2IG3

IG3 > IG2 > IG1

+IA

page 14

Thyristor

(a) circuit

(b) waveforms (c) turn-off time interval tq

~

R

0

vAKvs

iA+

−iG

+

−

iA

vsiAvAK

0t

T2T

iA

vAK

t

t

tn

tq

0

0

page 15

Switching Characteristics of SCR

IG

Time

+

+

IG

VA

+

trtd

ton0.9Ir

0.1Ir

Ir

tn

QR

IRM

tq

VDRM

VRVPRM

dtdi dt

di

dtdv

Reapplied

dtdv

state-Off

Recombination

Recovery

(a) gate current

(b) anode currents

(c) anode voltage

commutation

page 16

A Practical SCR Gate Drive Circuit

+ 36V1Ω

50µF0.47µF

50Ω

680Ω

42Ω

50Ω

0.047µF

42Ω

2N6303

2N3879

13Ω

Rs

gate

cathode

on

off

driv e f rom integrated circuit

page 17

GTO: Gate Turn-Off Thyristor

Behave like normal thyristor, but can be turned off using gate signal

However turning off is difficult. Need very large reverse gate current (normally 1/5 of anode current)

Ia

−

+

Ig

G(Gate)

K(Cathode)

A(Anode)

Vak

GTO: Symbol v-i characteristics

Vr

Ia

Vak

Ig >0 Ig =0IhIbo

page 18

Symbol and Characteristics Curve


iA

+

−

vGS

A

K

vAK

iG

G

On

0

Off0

iA

vAKvAK

iA

Turn-onTurn-off

Off-state



page 19

GTO Characteristics

Switching speed in the range of 5-25 micro seconds

Blocking voltage: 4500 V

Conducting current: 3000 A

Switching frequency applications: 100 Hz - 10 kHz

Gate drive design is very difficult. Need very large reverse gate current to turn off. Often custom-tailored to specific application.

Bilateral voltage block capability

Current triggered latch on

Can be turned off by applying a negative gate-cathode voltage

On-state voltage: 2-3 V

Low dv/dt, must be protected by turn-off snubber for inductive load

page 20

GTO Transient Characteristics

(a) snubber circuit (b) GTO turn-off characteristic

Snubber circuit to reduce dv/dt at turn-off

iA

A

vAKGTO

GGate drive circuit

C

DR

K 0 t

page 21

BJT: Bipolar Junction Transistor


iC

vCE

vBE

iB

C

E

B

+

−

+ −

iC

I

0 vCE(sat)iB=0

iB1

iB2

iB3

iB4

iB5

vCE

iC

vCE

On

Off

0

page 22

BJT Characteristics

Current-controlled bipolar carriers device

Can not be reverse biased

On-state voltage: 1-2 V

Long storage time during turn-off transition

Low current gain

Switching speed in the range of 0 .5-5 micro secondsBlocking voltage: 1500 V

Conducting current: 200-300 A

Switching frequency applications: 1-10 kHz

Negative temperature of on-state resistance

Secondary breakdown effect

page 23

Operating Principle

(a) 斷面結構圖 (b) 表示符號

基極

(base)

基極

電流

基極電流射極 (emitter)

電子的流動

集極

(collector)

+−+ −

n p

n

n+

電流控制電流

因VBE而有 IB流動，再以 IB控制 IC

VCE

VBE

IB

IC

BC

E

page 24

Structure and Symbol

極值—射極共通端子射極端子

集極端子外殼（蓋）

基櫪端子

鋁線

螺絲

外殼（本體）

散熱片安裝用銅板內部配線

基極電極

基極電極

矽晶片

M0板

絕緣基板

矽膠

射極電極還氧基電脂

B C

E



page 25

MD: Monolithic Darlingtons

(a) Darlington (b) triple Darlington

iC

vBEE

+

−

C

vCE

+

−

iB

B

vBE

B

+

iC

C

+

vCE−

E−

page 26

Collect-Emitter Characteristics of a Bipolar Power Transistor

SECONDBREAKDOWN

SATURATI ONREGI ON

ACTIVE

REGI ON

SUS TAI NINGREGI ON

PRI MARYBREAKDOWN

CEOCER

CES

CEV

Collect Emitter Voltage (V CE)

Col

lect

Cur

rent

(IC)

VCBO

QUAS I SATREGI ON

page 27

Safe Operating Area: FBSOA and RBSOA

FORWARD BIAS SAFE OPERATING AREA

V CE, CORRECT EMITTER VOLTAGE (VOLTS)

SECOND BREAKDOWN LIMITEDCURVES APPLY BELOW RATED V CEO

TC= 25 o

BOUNDING WIRE LIMITEDTHERMALLY LIMITED

100 µs1 ms

5 ms

dc

MJ10004

IC, C

olle

ct C

urre

nt (A

mp)

4 6 10 40 60 100 200 400

50

20

105

2

1

0.5

0.20.1

0.05

0.020.01

0.005

MJ10005

HIGH CURRENT DARLINGTON ROSOA

VBE (OFF) = 5V

V BE (OFF) = 2V

VBE (OFF) = 0V

VCE , CORRE CT EMITTER VOLTAGE (VOLTS)

Tj= 100 o

I C, C

olle

ct C

urre

nt (A

mp)

20

16

12

8

4

0

0 100 200 300 400 500

(a) Typical collect-emitter characteristics with its (b) turn-on SOA (FBSOA) and (c) turn-off SOA (FBSOA).

page 28

Waveforms for a Bipolar Power Transistor in a SPS

Vsat

tr tfts

IB2

time

time

timeSaturation Loss Turn-off loss,

Current Crowding Period

Turn-on Loss, Second

Breakdown Period

~~

~~

~~~~

IB1~ ~Colle ctor-Curre nt

Colle ctor-to-emitter V olta ge

Base Current

Ipk

Symbol

IB

IC

VBE

VCE

+

−−

+

BVBE

Rb

C

E

CCE

hFE = Ib

Approxi ma te E quiv alent Cir cui t

page 29

Power MOSFET

Power MOSFET vs. Power Bipolar Junction TransistorN-Channel MOSFETPower MOSFET CharacteristicsPlanar N-Channel Power MOSFETPower MOSFET Parasitic ComponentsTrench MOSFET

page 30

Characteristics of Power MOSFET

Ratings: Voltage VD S



page 31

Characteristics of Power MOSFET

Turning on and off is very simple. Only need to provide VGS =+15V to turn on and 0V to turn off. Gate drive circuit is simple.

Basically low voltage device. High voltage device are available up to 600V but with limited current. Can be paralle led quite easily for higher current capability.

Internal (dynamic) resistance between drain and source during onstate, RD S(ON), limits the power handling capability of MOSFET. High losses especially for high voltage device due to RDS(ON) .

Dominant in high frequency application (>100kHz). Biggest application is in switched-mode power supplies.

page 32

Power MOSFET vs. Power Bipolar Junction Transistor

Voltage Controlled Device vs. Current Controlled DeviceFast Switching Speed: Unipolar vs. Bipolar Devices (Presence of holes with their higher carrier lifetime causes the switching speed to be several orders of magnitude slower than for a power MOSFET of similar size and voltage rating.)

Thermal Runaway of BJTEasily to be paralleled At high breakdown voltages (>200V) the on-state voltage drop of the power MOSFET becomes higher than that of a similar size bipolar device with similar voltage rating.

Maximum Current (A)

Hol

doff

Vol

tage

(V)

2000

1500

1000

500

01 10 100 1000

BipolarTransistors

MOS

page 33

Physical Structure of NMOS and DMOS

Body

SiO2Gate

Source

Body

p-type substrate (Body)

Drain

p+p+

L

n+ n+

Metal

Channelregion

Enhancement-type NMOS Transistor

2)(21

tGSnoxD VvLWCi −⎟

⎠⎞

⎜⎝⎛= µ

Double-Diffused Vertical MOS Transistor (DMOS)

DrainCurrent flow

SiO2Gate

Source

Body

Substrate

source

p+p+

n+L

n+ n+

−n

Metal

)(21

tGSsatoxD VvWUCi −=

page 34

Power MOSFET

Power MOSFET (a) Schematic, (b) Transfer Characteristics, (c) Device Symbol.

(a)

(b)

(c)

iD

vGS

D

S

G

+−

SB(cha nnel or substra te)

VGS

ID

VT0

SourceContac t

Fiel dOxi de

Ga teOxi de

Ga teMe talliza tion

DrainContac t

n* Sourcen* Drai n

Cha nnel

p-S ubs tra te

tox

t

page 35

N-Channel MOSFET


iD

On

0

vGS=7V

+

−vGS

D

S

vDSG

+−

iD

Off

6V

5V

4VvDS

On

Off

vDS

iD

0

page 36

Power MOSFET Characteristics

Voltage-controlled device

Can not be reverse biased

On-state resistance:

Switching speed in the range of 10-300 nano seconds

Blocking voltage: 300-400 V

Conducting current: 20-100 A

Switching frequency applications: 30-500 kHz

Positive temperature of on-state resistance

7.25.2)(

−= DSSonDS kBVr



page 37

Planar N-Channel Power MOSFET

(a) Schematic

(b) Symbol

iD

vGS

D

S

G

+−

Source Ga teOxi de

SourceMe talliza tion

p* Body Re gion

n* Epi La yer

Cha nnel

p-S ubs tra te

Drift Re gion

n+ Substr ate(100)

Drain

DrainMe talliza tion

Pol ysilic onGa te

n+ n+p+

p

page 38

Trench MOSFET

(a) Current Crowding in V-Groove Trench MOSFET (b) Truncated V-Groove MOSFET

S SG

Electron Flow

D

SourceGate

Channel

Drain

Source

GateOxide

Oxide

n+ Substrate(100)

n- Epi Layer

page 39

Current-Voltage Characteristics of Power MOSFET

GateVoltage

(Sat

urat

ion

Regi

on)

Line

ar R

egio

n

Drain Voltage (Volts)

Nor

mal

ized

Dra

in C

urre

nt

25

20

15

10

5

00 5 10 15

1

2

3

4

5

6

7

IDC vs. VDC Locus

page 40

Breakdown Voltage

Breakdown voltage, BVDS S, is the voltage at which the reverse-biased body-drift diode breaks down and significant current starts to flow between the source and drain by the avalanche multiplication process, while the gate and source are shorted together.

VDS

ID

BVDSS

SharpSoft

page 41

On Resistance

The on-state resistance of a power MOSFET is made up of several components

RDS(on) = Rsource + Rch + RA + RJ + RD + Rsub + Rwc ml

whereRsource = Source diffusion resistanceRch = Channel resistanceRA = Accumulation resistanceRJ = "JFET" component-resistance of

the region between the two body regionsRD = Drift region resistanceRsub = Substrate resistanceRwcml = Sum of bond wire resistance

Drain

n+ Substrate

P-Base

Gate

Sourc e

RSOURCERCH

RJ

RA

RD

RSUB

N+

page 42

Contributions to RDS(on) with Different Voltage Ratings

Source

Cha nnel

Volta ge Rati ng:

Packagi ng

Me talliza tion

JFE TRegi on

ExpitaxialLa yer

Subs trate

50V 100V 500V

RWCML

RCH

REPI



page 43

Transconductance

Transconductance, gf s, is a measure of the sensi tivity of drain current to changes in gate-source bias.This parameter is normally quoted for a Vg s that gives a drain current equal to about one half of the maximum current rating value and for a VDS that ensures operation in the constant current region.

VGS

ID

Slope = gfs

page 44

Threshold Voltage

Threshold voltage, Vth, is defined as the minimum gate electrode bias required to strongly invert the surface under the poly and form a conducting channel between the source and the drain regions.Vth is usually measured at a drain-source current of 250mA. Common values are 2-4V for high voltage devices with thicker gate oxides, and 1-2V for lower voltage, logic-compatible devices with thinner gate oxides. With power MOSFETs finding increasing use in portable electronics and wireless communications where battery power is at a premium, the trend is toward lower values of RDS(on) and Vth.

page 45

Source-Drain (Body) Diode Forward Voltage Characteristics

iD

vGS

D

S

G

+−

The diode forward voltage, VF, is the guaranteed maximum forward drop of the body-drain diode at a specified value of source current. Left figure shows a typical I-V characteristics for this diode at two temperatures. P-channel devices have a higher VF due to the higher contact resistance between metal and p-silicon compared with n-type silicon.Maximum values of 1.6V for high voltage devices (>100V) and 1.0V for low voltage devices (



page 49

Switching Time Test

Turn-on delay, td(on), is the time taken to charge the input capacitance of the device before drain current conduction can start. Similarly, turn-off delay, td(off), is the time taken to discharge the capacitance after the device is switched off.

(a) Test circuit (b) VGS and VDS waveforms

VGS

VDS

100%

90%

td(on) td(off)tr tf

−

+VDD

VGS

VDS

RD

RG

D.U.T

-10VPulse Width ≤1µsDuty Facto r ≤ 0.1%

page 50

Gate Charge

Although input capacitance values are useful, they do not provide accurate results when comparing the switching performances of two devices from different manufacturers. Effects of device size and transconductance make such comparisons more difficult. A more useful parameter from the circuit design point of view is the gate charge rather than capacitance. Most manufacturers include both parameters on their data sheets. A small gate charge is desirable to reduce the turn-on and turn-off time.

(a) Test circuit (b) Gate and drain waveforms

cDS

D

D

S

G

ScGS

ID

ID

VDD

Test Circ uit

Ga teVolta ge

DrainVolta ge

Wav eform

Drain Curre nt

vDDID

VG

VG(TH)

t0 t1 t2 t3 t4t

OGS OGS

page 51

dV/dt Capability

Equivalent Circuit of Power MOSFET Showing Two Possible Mechanisms for dv/dt Induced Turn-on.A fast dv/dt will induce a fault turn-on.

dtdvCRRIV GDGG1GS ==

GDG

th

CRV

dtdv

=

SOURCE

APPLIEDRAMP

VOLTAGE

DRAI N

CGD

CGS

G

D

S

I2

I1

RG

page 52

Power MOSFET Parasitic Components

SOURCE

Cgsm

REPI

DRAIN

METAL

n-

P-

n- Epi La yer

n-

LTO

Rch

CGS1

RBBJ T

JFE T

CDS

CGD

CGS2

n+ substra te

page 53

Parasitic BJT Causes dv/dt Induced Turn-on

Physical Origin of the Parasitic BJT Components That May Cause dv/dt Induced Turn-on.

DBB

BE

CRV

dtdv

=

SOURCE

NPNBIPOLAR

TRANSISTOR

APPLIEDRAMP

VOLTAGE

RB

DRAI N

CDBCGD

CGS

G

D

S

I2

RG

SOURCEN+ A

LN+

RDB

CDB

DRAI N

GATE

N-

P-

N+ Epi La yer

page 54

Model of a Power MOSFET Including Parasitics

Ga te Driv er

If a power MOSFET being driven by a low impedance driver, the parasitics of the MOSFET and low output impedance of the gate drive constitute a low resistance LC tank around the gate-source loop. The MOSFET has both parasitic capacitances and parasitic inductances, and these form a resonant tank that can be excited into oscillation. Although the MOSFET has parasitic inductance, it should also be realized that in many cases the dominant inductance is caused by long traces. The parasitic inductance and trace inductance are in series, and both contribute to the tank.

vGS



page 55

The Cure for Gate Ringing

The most important means of avoiding ringing is minimizing the inductance, which means having as short a trace length as possible between the gate dr iver and the gate.The model of the MOSFET’s parasitics also makes it evident what one possible solution would be to suppressing this r inging if layout is less than optimal: addition of a damping resistor to decrease the Q of the tank. In particular, adding a resistor in series w ith the gate will suppress oscillations. The resistor should be as close as physically possible to the gate of the MOSFET.

Adding a 4.7Ω damping resistor to each paralle led MOSFETs. In the case of multiple paralle led MOSFETs, since there are multiple resonant tanks, having a single gate resistor is not enough: the only way to ensure that there will not be ringing is for each individual MOSFET to have its own gate resistor .

page 56

What Value of Gate Resistor?

As can be seen, efficiency decreases as gate resistance increases. To ensure oscillation suppression while avoiding degradation of converter efficiency, Fairchild recommends: Use a 4.7Ω gate resistor for every power MOSFET used in a switching converter; in particular, use a separate 4.7Ω gate resistor for each paralleled MOSFET.

Gate Resistance (Ω ) Change in Efficiency0 0 (nominal)

3.3 -0.4%4.7 -0.8%10 -2.9%20 -5.6%

Gate Resistance0 5 10 15 20

0

-2

-4

-6Los

s in

Effi

cien

cy (%

)

page 57

Gate Resistor for a Buck DC-DC Converter

Adding a 4.7Ω gate resistor for each power MOSFET.Layout of traces around the gate-source loop should be as short as possible to reduce parasitic inductances.

Gate Resistance

+12V

+5V

VREF

GND

VID4

VID0VID1

VID2VID3

ENABLE

VO

Power

VCC

C4C5

L2

C71234567891011

121314151617181920

C6

C12

R5D1

R7

R9

R10 M3 M4

L1

C8 C9

R6

C11

C10

0.1µF

0.1µF

M1M2

4.7Ω

4.7Ω

1.3µH

1µF

4.7Ω 4.7ΩR8

47Ω

1µF DS11N5817 COUT*

RSENSE*

10kΩ

0.1µF

1N4735A

RC5051

CEXT100pF

0.1µF

0.1µF

0.1µF2.5µH

CIN*

0.1µF

page 58

Power MOSFET: Considerations and Applications

Power MOSFETs have been the preferred device under these conditions:High frequency applications (>200kHz)Wide line or load variationsLong duty cyclesLow-voltage applications (



page 61

IGBT: Insulated Gate Bipolar Transistor

IGBT: Symbol and CharacteristicsFeatures of IGBTIntelligent Power Module

page 62

IGBT: Insulated Gate Bipolar Transistor

(a) symbol

(b) i-v characteristics (c) idealized characteristics

iD

G

C

E

G

D

S

vDS+

−

iD

0 0

vGS+

−

vGS

vDS

iD

vDS

OnOff

vRM

BVDSS

page 63

Characteristics

Ratings: Voltage: VCE



page 67

IGBT: Considerations and Applications

IGBTs have been the preferred device under these conditions:Low duty cycleLow frequency (1000V)Operation at high junction temperature is allowed (>100°C)>5kW output power

Typical IGBT applications include:Motor control: Frequency



page 73

Drive and Snubber Circuits

Base Drive for Power Semiconductor Switches

1. Highly depend on the controlled power devices

2. Integrate with the power device => IPM

Snubber

1. Turn-on snubber

2. Turn-off snubber

3. Stress reduction snubber

page 74

Switching Trajectories of a Power Transistor with Inductive Load

Switch with inductive load

current sensing resistor

VCC+

Measurement of load line

vCE

iC VCC0

load line

turn off

turn on

switch

vCE

iC

VCC0

turn off

turn on

VCC0

turn off

turn on

Switch with inductiv e load shunted by a

diode

Switch with inductiv e load shunted by a

diode and capacitor

page 75

Selection of Power Devices

1.On-state voltage or on-state resistance dictates the conduction losses in the device

2.Switching times

page 76

Justification for Using Idealized Device

1. On-state voltage



page 79

Switching Loss Analysis

Switching LossTransistor Switching with Clamped Inductive LoadSwitching Loss Induced by Transistor Turn-off TransitionDiode Recovered ChargeIR PIIPM50P12B004: Programmable Isolated IPMMatrix Converter Motor (MCM)

page 80

Switching Loss

Energy is lost during the semiconductor switching transitions, via several mechanisms:

Transistor switching timesDiode stored chargeEnergy stored in device capaci tances and parasitic inductances

Semiconductor devices are charge controlled

Time required to insert or remove the controlling charge determines switching times

page 81

Transistor Switching with Clamped Inductive Load

Buck Converter Example

Transistor turn-offtransitiongAB Vtvtv −= )()(

LBA ititi =+ )()(

)( 0221 ttiVW Lgoff −=

t

t

t

0 0

0 0

transistor waveforms

diode waveforms

gV

gV−

Li

Li

LgiV

)(tvA

)(tiA

)(tiB

)(tvB

AA

A

tvtP

=)(

offWarea

0t 1t 2t

)(tiL

Bi

LAv

Bv

Ai

gV

PhysicalMOS FET

idealdiode

gatedriver

+

++

+

–

–

– –

sTsDT

page 82

Switching Loss Induced by Transistor Turn-off Transition

Energy lost during transistor turn-off transition:

Similar result during transistor turn-on transition.Average power loss:

)( 0221 ttiVW Lgoff −=

∫ +==nstransistio

switchingsoffonA

ssw fWWdttpT

P )()(1

page 83

Switching Loss Due to Current-Tailing in IGBT

∫ +==nstransistio

switchingsoffonA

ssw fWWdttpT

P )()(1

Example: buck converter with IGBT

Transistor turn-offtransition

t

t

t

0 0

0 0

IGBT waveforms

diode waveforms

gV

gV−

Li

Li

LgiV

)(tvA)(tiA

)(tiB

)(tvB

AA

A

tvtP

=)(

offWarea

0t 1t 2t 3t

current tail

)(tiL

Bi

LAv

Bv

Ai

gV

PhysicalIGB T

idealdiode

gatedriver

+

++

+

–

–

– –

sTsDT

page 84

Diode Recovered Charge

Diode recovered stored charge Qrflows through transistor during transistor turn-on transition, inducing switching loss

Qr depends on diode on-state forward current, and on the rate-of-change of diode current during diode turn-off transition

transistor waveforms

diode waveforms

AA

A

tvtP

=)(

t0 0

0 0t

t0t 1t 2t

gV

gV−

Li

rgL tVi~

)( tv A

)(tiA

)(tiB

)( tv B

Li

rQ

rQ−

gr VQ~

area

area

tr

area

)(ti L

Bi

LAv

Bv

Ai

gV

fasttransistor

idealdiode

+

++

+

–

–

– –



page 85

Switching Loss Calculation

Energy lost in transistor:

With abrupt-recovery diode:

Often, this is the largest component of switching loss

∫=nstransistio

switchingAAD dttitvW )()(

∫ −≈nstransistio

switchingBLgD dttiivW ))((

rgrLg QVtiV +=

Soft-recovery diode:

Abrupt-recovery diode:

)()( 0112 tttt −>>−

)()( 0112 tttt − 0Negative inductor current removes diode stored charge QrWhen diode becomes reverse-biased, negative inductor current flows through capacitor C.Ringing of L-C network is damped by parasitic losses. Ringing energy is lost.

)(ti L

)(ti B

L

)(tvBgVsilicondiode

+

+

––

+ –

C

)(tvLt

2V−

)(tvi

t

t

0

0

0

)(tiL

)( tv B

1V

2V−

1t 2t 3t

rQ−area



page 91

Energy associated with ringing

Recovered charge is ∫−=3

2

)(t

t LrdttiQ

Applied inductor voltage during interval

:32 ttt ≤≤Energy stored in inductor during interval

∫=3

2

)()(t

t LLLdttitvW

:32 ttt ≤≤

2)()( V

dttdiLtv LL −==

Hence,

rLL

t

t L

t

t LL

L

QVtLiW

dttiVdttidt

tdiLW

232

21

2

)(

)()()()( 32

3

2

==

−== ∫∫

t

2V−

)(tvi

t

t

0

0

0

)(tiL

)(tvB

1V

2V−

1t 2t 3t

rQ−area

page 92

Efficiency vs. switching frequency

Add up all of the energy lost during the switching transitions of one switching period:

Average switching power loss is

...+++++= LCDoffontot WWWWWW

swtotsw fWP =Total converter loss can be expressed as

swtotfixedcondloss fWPPP ++=

where ) and load of nt(independe losses fixed swfixed fP =losses conduction=fcondP

page 93

Efficiency vs. Switching Frequency

Switching losses are equal to the other converter losses at the critical frequency

This can be taken as a rough upper limit on the switching frequency of a practical converter. For fsw>fcrit, the efficiency decreases rapidly with frequency.

tot

fixedcondcrit W

PPf

+=

swtotfixedcondloss fWPPP ++=

10kHz 100kHz 1MHz50%

60%

70%

80%

90%

100%

dc asymptote

fcrit

fsw

η

page 94

Future Development

Power Integration TrendIntelligent Power ModuleIR PIIPM50P12B004: Programmable Isolated IPMMatrix Converter Motor (MCM)

page 95

Power Integration Trends

SIGNAL IC’s AND VLSI

Power (kVA)

1,000

100

10

1

0.1

0.01

INTEGRATION LEV EL

SMART POWER

MODULES AND HYBRIDS (To DAY)

DISCRETE COMPONENTS

MODULES AND HYBRIDS (Future)

page 96

IPM: Intelligent Power Module

Intelligent Power Modules (IPMs) are advanced hybrid pow er devices that combine high speed, low loss IGBTs w ith optimized gate drive and protection circuitry.

Highly effective over-current and short-circuit protection is realized through the use of advanced current sense IGBT chips that allow continuous monitoring of pow er device current.

System reliability is further enhanced by the IPM’s integrated over temperature and under voltage lock out protection.

Compact, automatically assembled Intelligent Pow er Modules are designed to reduce system size, cost, and time to market.

P

N

WVUS



page 97

Intelligent Power Module

page 98

Development Trend of IPM

技術困難

技術演進

• 功率密度~5-10W/inch3

•高度>1英吋

• 功率密度~10-90W/inch3

•高度~0.5-1英吋Multi-Module

Multilayer

• 功率密度>100W/inch3

•高度



page 103

References

[1] A. Lidow, D. Kinzer, G. Sheridan, and D. Tam, "The semiconductor roadmap for power management in the new millennium," IEEE Proc., Special Issue on Power Electronics Technology: Present Trends & Future Developments, June 2001.

[2] K. Satoh and M. Yamamoto, "The present state of the art in high-power semiconductor dev ices," IEEE Proc., Special Issue on Power Electronics Technology: Present Trends & Future Developments, June 2001.

[3] B. J. Baliga "The f uture of power semiconductor device technology," IEEE Proc., Special Issue on Power Electronics Technology: Present Trends & Future Developments, June 2001.

[4] P. L. Hower, "Power semiconductor dev ices: an overview," IEEE Proc., v ol. 76, no. 4, pp. 335-342, April 1988.

[5] R. Sitting and P. Roggwiller (Eds.), Semiconductor Devices for Power Conditioning, Plenum, New York, 1982.

[6] M. S. Adler, S. W. Westbrook, and A. J. Yerman, “Power semiconductor dev ices - an assessment,” IEEE IAS Conf. Rec., pp. 723-728, 1980.

[7] Dav id L. Blackburn, “Status and trends in power semiconductor devices,” EPE Conf. Rec., vol. 2, pp. 619-625, 1993.

[8] B. Jayant Baliga, Modern Power Devices, John Wiley & Sons, Inc., New York, 1987.[9] User’s Guide to MOS Controlled Thyristors, Harris Semiconductor, 1993.[10] S. M. Sze, "Physics of Semiconductor Dev ices,“[11] HEXFET Power MOSFET Designer's Manual - Application Notes and Reliability Data," International Rectifier [12] Edwin S. Oxner, Power FETs and Their Applications[13] Duncan A. Grant and John Gower, Power MOSFETs - Theory and Applications,

overview of power semiconductor...

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