MA300E17_EVAL Infineon Technologies, MA300E17_EVAL Datasheet - Page 12

• Manufacturer Part Number: MA300E17_EVAL
• Description: Power Management IC Development Tools MOD ADPTR BRD FOR 1700V PRIMEPACK IGBT
• Manufacturer: Infineon Technologies

Module Adapter Board
for PrimePACK
Figure 10
3.6
The switching frequency of an IGBT is limited either by the maximal power of the driver voltage supply
or by the maximal temperature of the PCB due to the power losses in the external gate resistors.
These power losses in the gate resistors depend on the IGBT gate charge, gate voltage magnitude
and on the switching frequency of the IGBT. Due to the power losses in the external gate resistors, the
heat will be generated, which leads to increase of the PCB temperature in the neighborhood of these
resistors. This temperature must not be higher than the melting temperature of the PCB, i.e. 105°C for
a standard FR4 material. The calculation of the power losses in the gate resistors can be done by
utilizing Equation 1:
where:
P
∆V
f
Q
The complete gate resistor consists of the internal gate resistor R
resistor R
DCB into the base plate, whereas the other part of the power losses will be dissipated externally in the
ambient air and in the PCB. The ratio of the losses dissipated internally P(R
P(R
presents a measurement result showing the external gate resistor temperature in dependency on the
power transformed in that resistor. It can be read from the graph, that for the ambient temperature of
25°C and the base plate temperature of 125°C the maximal temperature of the PCB reaches 105°C
with power losses in R
not the DC-DC converter, with its available power of 4W pro channel, but the maximal temperature of
the PCB. Higher switching frequency can be only obtained by utilizing a PCB with higher melting
temperature.
P
s
dis
G
dis
= switching frequency,
out
= IGBT gate charge (for the given gate voltage range)
GEXT
= dissipated power,
= voltage step at the driver output
P
) corresponds directly to the ratio of the mentioned R
(
GEXT
R
EXT
Switching off behavior of the FF1000R17IE4 PrimePACK™ module with boosted
active clamping where: V
Maximum switching frequency
and due to that, a part of the IGBT power losses will be dissipated directly through the
)
P
(
R
TM
GEXT
INT
0.2µs/div
0.2µs/div
)
equal to 1.1W. In that case, the limiting factor for the switching frequency is
IGBT Modules
V
out
v
v
5V/div
5V/div
GE
GE
f
(t)
(t)
DC
s
=900V, I
Q
G
12
C
I
I
=2500A, R
gate
gate
(t)
(t)
(1)
5A/div
5A/div
v
v
i
i
5V/div
5V/div
5A/div
5A/div
AVCdiodes
AVCdiodes
driver
driver
Goff
=1,5 and T
GINT
(t)
(t)
GINT
(t)
(t)
and R
together with an external gate
GEXT
J
=25°C
Application Note AN 2007-06
resistors. Figure 11
GINT
) and externally
V1.2, June 2010