Discrete IGBT datasheet understanding - Infineon … · Discrete IGBT datasheet understanding Zhou Wei(周伟) System application engineer Infineon Technologies China [email protected]

Discrete IGBT datasheet understanding

Zhou Wei(周伟)

System application engineer

Infineon Technologies China

[email protected]

Page 2 Copyright © Infineon Technologies 2008. All rights reserved. 21.10.2011

Product Qualifications & Team Structure Infineon IGBT Chip Technology


Product Qualifications & Team Structure Datasheet understanding

Electrical characteristic

Switching characteristic

Thermal features

Page 3 Copyright © Infineon Technologies 2008. All rights reserved. 2011/10/21

Behaviour: IGBT vs MOSFET

VCEs

at VDS

IC

ID

The IGBT is characterized by it‘s pn

threshold voltage. Conduction loss are in

linear relation to IC

The MOSFET behaves like a resistor.

Conduction loss are proportional to ID²

The IGBT has a characteristic current tail.

Turn off losses are dominated by the tail

current.

IGBT is basically the preferred device for higher currents at limited pulse frequencies.

pn threshold voltage

VCE

t

IC

current tail

ID

UDS


Infineon´s IGBT history for Drives Product Technologies


Vertical IGBT Concepts

Punch Through Non Punch Through Trench + Field-Stop

-E

Collector

Emitter Gate

-E

Collector

Emitter Gate

-E

Collector

Emitter Gate

n- basis (epi)

n+ buffer (epi)

p+ emitter (substrate)

n- basis (substrate)

n- basis (substrate)

Advantage

• Implanted Back-Emitter better

adjustable

Performance

• Lower Schwitching Losses

• Higher Switching Robustness

Advantage

• Implanted Back-Emitter

• Implanted Fieldstop enables

thinner base region

Performance

• Lower VCEsat

• Lower Switching Losses

• Robustness like NPT

(ROW: 1988) (IFX: 1990 ROW: 1997) (IFX: 2000)


Standard planar IGBT are still good, but they have …

Emitter

Gate

Collector p+

n+

p+

n-(substrate)

• …high conduction losses, due to high

VCE(sat)

• …low switching performance, due to low

switching speed

• …poor thermal properties, due to thick

wafers

New Technologies are necessary to meet tomorrows requirements


How to improve the standard IGBT-technology?

Emitter

Gate

Collector p+

n+

p+

n-(substrate)

n ( fieldstop )

• Improvement of thin wafer technology

(Fieldstop) reduces VCE(sat) dramatically

Reduction of Conduction Losses for higher Efficiency and

improved thermal properties

Reduction of Swtiching Losses for higher Efficiency

Infineon´s TrenchStop ® -Technology meets today tomorrow´s requirements

• Introduction of trench gate technology

reduces VCE(sat) further

Reduction of Conduction Losses for higher Efficiency

Emitter

Gate

Collector p+

n+

p+

n-(substrate)

n (fieldstop)

Emitter

Gate

Collector p+

n+

p+

n-(substrate)

n (fieldstop)• Well established thinwafer technology

lowers VCE(sat) & Eoff furthermore

• Introduction of RC Diode technology







Thermal features


Current parameters (IKW50N60T)

Nominal current (Ic)

* * Tjmax @ max Tjmax Rthjc Ic C Vcesat C Tc ° - ° =

All nominal current is specified at 100 /110℃,25℃ value is also given as reference.

Ic is calculated as below:

This value just represents IGBT DC behavior, can be a reference of choosing IGBT, but not yardstick.

Tc> 100°C

Tc set to 100°C

IKW50N60T Tj=175°C

Vcesat=2.4V Ic=50A

Rthjc=0.45°C/W

IKW50N60T

Tc=121°C

Page 10 Copyright © Infineon Technologies 2008. All rights reserved.

Current Limitation (IKW50N60T)

RthjcPtotTjc =

CECtot VIP =

CECTOCE RIVV =

CE

TO

CEthjc

cjCETOthjc

CR

V

RR

TTRVRI

-

-=

22

4 max

2

Calculation of Max. DC Current


Current Limitation

Value limited by bondwire

IKW50N60T in TO-247 IHW20N120R3 in TO-247


Pulse collector current (IKW50N60T)

Pulse current (Icpuls)

Icpuls is defined as repetitive turn on & maximum turn off pulse current

3 ~ 4 times of Ic ,according to different technology


VCES – Breakdown Voltage (IKW50N60T)

VCES

VCES－test condition

Max. collector－emitter voltage under condition of gate and emitter shorted, where leakage current is within spec.

Vces under Tj=25℃, proportional to its junction temperature

Vces can not be violated at any condition, otherwise IGBT would break down.


In real application, turn-off voltage need to be smaller

than max. VCES

IKW50N60T

Max. VCES can be shunt donw

Due to the stray inductance

ΔV= Lσ * di/dt

VCES – Breakdown Voltage (IKW50N60T)


Voltage parameters (IKW50N60T)

Vcesat

Vcesat is specified at nominal current

Positive coefficient Good for paralleling


Voltage parameters (IKW50N60T)

Vcesat increase with Ic increasing

Vcesat increase with Vge decreasing

Vge is not recommended to use too small: conduction losses


VGEth (IKW50N60T)

Pay attention to negative temperature coefficient of VGEth.

Threshold of IGBT turn on:


Max operation junction temperature (IKW50N60T)

Tjmax is the max temperature for IGBT to sustain all electrical parameters within spec.

Never exceed Tjmax at any condition! Otherwise, IGBT will run away fail!







Thermal features


Short circuit current (IKW25N120T2)

Different value for various start junction condition.


Short circuit current & time (IKW25N120T2)

10us guaranteed at test condition.


Current parameters (IKW25N120T2)

Short circuit condition:

¬ Vge: gate voltage (15V)

¬ Vcc: DC bus voltage

¬ Tvj: short circuit start temperature

Infineon test short circuit at maximum operation Tj

Vge

Isc

tsc


Switching parameters (IKW50N60T)

Qgate

Ciss, Crss, Coss

This value is specified at +15V, used to calculate driving power

E

C

G

CGC

CGE

CEC

Ciss = CGE + CGC: Input capacitance (output shorted) Coss = CGC + CEC: Output capacitance (input shorted) Crss = CGC: Reverse transfer capacitance (Miller capacitance)

fVQP GEg =







Thermal features


Chip

Solder

Copper Baseplate

Heatsink

Tj

Tc

Th

Ta

Chip – Case

Tjc

Case – Heatsink

Tch

Heatsink – Ambient

Tha

Rthjc

Input Power Output Power Power Loss

Tj = Tjc + Tch + Tha + Ta

Rthch

Rthha

Thermal Grease

Thermal Features

IGBT-thermal model

Rth(j-a) = Rth(j-c) + Rth(c-s) + Rth(s-a)


Rth JC ; Rth CH

IGBT Thermal Resistance (IKW50N60T)


Ptot-total power dissipation

Tjmax = Tc+Ptot*Rthjc (max)

Rated at 25℃

Ptot =(Tjmax- Tc)/Rthjc (max)

IGBT Power Dissipation & Junction Temp. (IKW50N60T)

Documents

Discrete IGBT datasheet understanding - Infineon … · Discrete IGBT datasheet understanding Zhou Wei(周伟) System application engineer Infineon Technologies China [email protected]