Infineon datasheet
understanding
IFX AIM
Zhou Yizheng
Infineon datasheet understanding
Current
Current parameters
parameters
Voltage
Voltage parameters
parameters
Switching
Switching parameters
parameters
Diode
Diode parameters
parameters
Thermal
Thermal parameters
parameters
Module
Module parameters
parameters
For internal use only
Page 2
Current parameters
! Nominal current (ICnom)
Specified as data code: FF450R17ME3
Nominal current is specified at 80℃, 25℃ value is also given as reference
Tc = T j max − (Vcesat ,max @ T j max * I Cnom * Rthjc )
Calculated value will be higher than datasheet value,
all nominal current is taken as integer
This value just represents IGBT DC behavior, can be a reference of
choosing IGBT, but not yardstick.
For internal use only
Page 3
Current parameters
! Pulse current (ICRM IRBSOA)
ICRM is defined as repetitive turn on pulse current
IRBSOA is defined as maximum turn off current
IRBSOA
ICRM
IC
VCE
VGE
1ms is just test condition, real pulse width is depend on thermal
For internal use only
Page 4
Current parameters
! Short circuit current (ISC)
IscI Short before Switch On
VCE
VCE
IC
IC
VGE
VGE
IscII Short after Switch On
The short circuit current value is a typical value. In applications, the
short circuit time should not exceed 10us.
For internal use only
Page 5
Current parameters
! Short circuit condition:
¬ VGE: gate voltage (15V)
¬ VCC: DC bus voltage
¬ Tvj: short circuit start temperature
VGE
ISC
tSC
Infineon test short circuit at maximum operation Tj
For internal use only
Page 6
Voltage parameters
! Blocking voltage (VCES)
VCES specified at Tj=25℃. Higher Tj, higher blocking voltage
Chip level
Module level
Due to stray inductance inside module
∆V = di / dt * Lδ
RBSOA
VCES is easiest to be exceed during
turn off, due to external and internal
stray inductance
VCES can not be violated at any condition, otherwise IGBT would
break though
For internal use only
Page 7
Voltage parameters
! Saturation voltage (VCEsat)
VCEsat is specified at nominal current, both Tj=25℃ and 125℃ are given
Infineon IGBT are all positive
temperature coefficient
Good for paralleling
VCEsat value is totally at chip
level, excluding lead resistance
For internal use only
Page 8
Voltage parameters
VCEsat increase with IC increasing
VCEsat increase with VGE decreasing
VGE is not recommended to use too small, This increases IGBT both
conduction and switching losses
For internal use only
Page 9
Voltage parameters
VCEsat value is used to calculate conduction losses
VCE = VT 0 + RCE * I C
RCE
ΔIC
∆VCE VCE ( 2) − VCE (1)
=
=
I C ( 2) − I C (1)
∆I C
Basic data for conduction losses calculation
RCE
ΔVCE
Tangent point should set close to operating point
VT0
For SPWM control, the conduction losses is:
2
Pcond , IGBT
1
IP
IP
IP
1
2
= (VT 0 * + RCE *
) + m * cos ϕ * (VT 0 * +
* RCE * I P )
π
2
4
8 3π
For internal use only
m: modulation fact; IP: output peak current; cosφ: power factor
Page 10
Switching parameters
! Internal gate resistor (RGint)
To realize module internal chip current sharing, module integrate internal gate
resistor. This value should be considered as one part of total gate resistor to
calculate peak current capability of a driver
For internal use only
Page 11
Switching parameters
! External gate resistor (RGext)
External gate resistor is what user can set, this value influence IGBT switching
performance
The minimum recommended Rgext is shown in the switching test condition
User can get different RGon and RGoff by a decoupling diode
RGon = R1 // R2 , RGoff = R2
This is just an example. There are a lot of circuit to realize it
Minimum RGon is limited by turn on di/dt, minimum RGoff is limited by
turn off dv/dt. Too small RG cause oscillation and may destroy IGBT
and diode
For internal use only
Page 12
Switching parameters
! External gate capacitor (CGE)
High voltage module is recommended to used external CGE to control gate
turn on speed.
With external CGE, turn on di/dt and dv/dt can be decoupled. This help to
realize low turn on losses with limited turn on di/dt
CGE
RG
For internal use only
di/dt
dv/dt
di/dt
dv/dt
Page 13
Switching parameters
! Rgint limitation
Rg _ ext
Rg _ int
Ro
Minimum RGext for IGBT
15 − Vss
15 − (−15)
≤
RO + RGext + RG int RGext _ datasheet + RG int
Minimum RGext for Driver capability
15 − Vss
≤ I O max
RO + RGext + RG int
If driver capability is not enough, IGBT switching performance will be
seriously influenced
For internal use only
Page 14
Switching parameters
! Gate charge (QG)
This value is specified at +/-15V, used to calculate driving power
! Cies, Cres
Cies = CGE + CGC: Input capacitance (output shorted)
Coss = CGC + CEC: Output capacitance (input shorted)
Cres = CGC: Reverse transfer capacitance (Miller capacitance)
Required gate power at
switching frequency f:
For internal use only
P = Qg ⋅ ∆VGE ⋅ f
P = Cies ⋅ 5 ⋅ ∆VGE ⋅ f
C
CGC
CEC
G
CGE
2
E
Page 15
Switching parameters
! Switching time (tdon, tr, tdoff, tf)
These values are greatly influenced by IG(RG), IC, VGE, Tj. These value can be
used to determine the dead time:
t DT = (((t doff max + t f max ) − t don min ) + t PHL max − t PLH min ))) *1.5
tPHLmax: driver output high to low delay
tPLHmin: driver output low to high delay
For internal use only
Page 16
Switching parameters
vGE
0,9*VGE
0,1*VGE
t
vCE(t)
iC
iC(t)
VCE
ICM
vCE
0,9*ICM
0,9*ICM
0,1*ICM
tr
td(off)
tf
•td(off):
90%VGE to 90%ICM
•tf :
90%ICM to 10%ICM
For internal use only
0,02*VCC
0,1*ICM
t
td(on)
•tr :
10%ICM to 90%ICM
•td(on):
10%VGE to 10%ICM
Page 17
Switching parameters
! Switching losses (Eon, Eoff)
•Eon:
10%IC to 2%VCE
•Eoff:
10%VCE to 2%IC
Infineon define switching losses by “10%-2%” integration limit .
While some competitors define switching losses by “10%-10%”
integration limit. This leads to 10 – 25% lower losses value.
For internal use only
Page 18
Switching parameters
Eon, Eoff depend on IC, VCE, driver capability (VGE, IG, RG), Tj and
stray inductance.
We assume that Eon/Eoff is in proportional with IC, and in certain range in
proportional with VCE (20%)
Eon = Eon _ nom *
Eoff
IC
VCE
*
I C _ nom VCE _ test
I
V
= Eoff _ nom * C * CE
I C _ nom VCE _ test
IGBT switching loss:
PSW = f SW * ( Eon + Eoff )
For internal use only
Page 19
Diode parameters
! Blocking voltage (VRRM)
Similar definition of VCES at Tj 25℃
! Nominal current (IF)
Tc = T j max − (VF ,max * I F * Rthjc )
! Pulse current (ICRM)
Similar definition of ICRM, two time of IF.
For internal use only
Page 20
Diode parameters
! Surge capability (I2t)
This value define the surge current capability of diode, used to select input fuse.
Fuse I2t value should be lower than diode I2t value, and action time should lower
than 10ms, other wise derating should be applied
We specified I2T value at Tj=125℃, if specified at Tj=25℃, I2t value can be much
bigger. We can judge diode current capability from I2t.
! Forward voltage (VF)
Similar definition of VCEsat, both Tj=25℃ and 125℃ are given, this
value is used to calculate diode conduction losses
Different from general understanding of diode, some Infineon diode
show positive temperature coefficient above certain current. This is
good for diode current sharing
For internal use only
Page 21
Diode parameters
! Switching parameters (IRM, Qr, Erec)
Diode reversy recovery are greatly influenced
by IGBT turn on di/dt, IC, Tj.
Irm and Qr are just test typical value, Erec is
used to calculate diode switching losses
Erec = Erec _ nom *
For internal use only
IC
*
VR
I C _ nom VR _ test
Page 22
Diode parameters
! Diode SOA
2,5
High voltage module specify the SOA of diode. Not only
peak current and voltage is limited, peak power also is
restricted.
The instantaneous peak power should never exceed the
limit for the max. power given in the SOA diagram.
2
1,5
1
0,5
0
0
1000
2000
3000
VR [V]
3000
3
2000
2
IR(t) [A]
VR [500V/div] IR [500A/div]
2000
1000
!
!
1
1000
0
0
locus iR(t)*vR(t)
2
1000
0
2000
0
1
time [400ns/div]
For internal use only
0
1000
2000
3
3000
VR(t) [V]
Page 23
Thermal parameters
! Thermal resistance:
Input Power
Power Loss
Output Power
Chip
Chip-Case
Thermal Resistance
– RthJC
Solder
Copper Layer
Ceramic (Al2O3 / AlN)
Copper
Solder
Base Plate
Case-Heatsink
Thermal Resistance
– RthCH
Heatsink(-Ambient)
Thermal Resistance
– RthHA
Thermal Grease
Heatsink
Junction Temp. – Tj
Chip – Case ∆Tjc
Case Temp. – Tc
Case – Heatsink ∆Tch
Heatsink Temp. – Th
Heatsink – Ambient ∆Tha
Ambient Temp. – Ta
Tj = ∆Tjc + ∆Tch + ∆Tha + Ta
For internal use only
Page 24
Thermal parameters
! Rth per IGBT
! Rth per diode
! Rth per module
We assume heat sink is isothermal:
Th = Ta + Ptot * RthHA
T j _ IGBT = Th + PIGBT * ( RthJC _ IGBT + RthCH _ IGBT )
T j _ Diode = Th + PDiode * ( RthJC _ Diode + RthCH _ Diode )
For internal use only
Page 25
Thermal parameters
per IGBT
per diode
per arm
per module
RthCH _ arm = RthCH _mod ule * n
RthCH _ arm = RthCH _IGBT // RthCH _ Diode
n is the number of arms per module
If only RthCH per module is given, we can calculate RthCH per IGBT and Diode
in the following way:
RthCH _ IGBT =
RthJC _ IGBT + RthJC _ Diode
RthJC _ Diode
For internal use only
* RthCH _ mod ule
RthCH _ Diode =
RthJC _ IGBT + RthJC _ Diode
RthJC _ IGBT
* RthCH _ mod ule
Page 26
Thermal parameters
! Thermal impedance (ZthJC)
Thermal impedance is used to calculate
instantaneous Tj
We provide four-stage partial fraction
model of Chip thermal impedance. Partial
fraction coefficients are also listed in
datasheet.
Z th , RCi = Rth ,i ⋅ (1 − e
−
t
τi
)
Z thJC = Z th , RC 1 + Z th , RC 2 + Z th , RC 3 + Z th , RC 4
For internal use only
Page 27
Thermal parameters
Simulation Result: IGBT Tj under different inverter output frequencies
Same output power, but with different output frequency leads to a big
difference of peak Tj. For detail calculation, please refer to Infineon IGBT
module simulation software IPOSIM
http://www.infineon.com/cms/en/product/channel.html?channel=ff80808112ab681d0112ab69e66f0362
For internal use only
Page 28
Module parameters
! Isolation test
All modules have passed dielectric test based on IEC1287, except 1200V module
which is for industrial application. 1200V module can fulfill VDE0160/EN50178
The Dielectric test means severe stress to the module. The standard recommends a
reduction to 85% of the initial test voltage, if the test should be repeated at the customer
High voltage module also apply partial discharge test based on IEC1287. This
guarantee long time working reliability.
For internal use only
Page 29
Module parameters
! Internal stray inductance
LsCE defines the module internal stray inductance between power terminals
Single module
Dual module with two
independent switches
HalfBridge, 4-PACK,
Six PACK module
PIM Module
For internal use only
Inductance of whole switch
Inductance of one switch
Inductance of one bridge
Specify the loop with
highest inductance
Inductance from P to N,
with the biggest loop
Page 30
Module parameters
! Lead resistance (RCC’+EE’)
This value means the resistive value of the connection between power terminals
and chips.
This is typical value given for one arm at Tc = 25℃
The losses on lead resistance is
added to module case directly
For internal use only
Page 31
Module parameters
! DC stability (VCED)
For high voltage module, cosmic rays effect becomes more serious. The DC
voltage to achieve a neglectable failure rate of 100 fit is defined in the data sheet.
The DC stability voltage is at room temperature and sea level. It is not
recommended to set DC voltage higher than VCED
VCE
Tvj
FIT
Altitude
r
A failure rate λ is defined by the number of failures r during an operation time t of n components: λ =
n⋅t
.
The unit for failure rates is 1 fit (failures in time) = 1*10-9 h-1, meaning one failure in 109 operating hours of a device.
For internal use only
Page 32