IR22141 International Rectifier, IR22141 Datasheet - Page 25

• Manufacturer Part Number: IR22141
• Description: HALF-BRIDGE GATE DRIVER IC
• Manufacturer: International Rectifier

Sizing the turn-off gate resistor
The worst case in sizing the turn-off resistor R
is when the collector of the IGBT in off state is
forced to commutate by external events (i.e. the
turn-on of the companion IGBT).
In this case the dV/dt of the output node induces
a parasitic current through C
and R
If the voltage drop at the gate exceeds the thresh-
old voltage of the IGBT, the device may self turn
on causing large oscillation and relevant cross
conduction.
Figure 22: R
Side is off and High Side turns on
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Table 1: t
Table 3: R
Table 2: dV
ON
IGBT
IRGP30B120K(D)
IRG4PH30K(D)
IGBT
IRGP30B120K(D)
IRG4PH30K(D)
IGBT
IRGP30B120K(D)
IRG4PH30K(D)
DRn
(see figure 22).
R
sw
DRn
Goff
Goff
OUT
driven R
R
sizing
sizing: current path when Low
HS Turning ON
Goff
/dt driven R
Qge
19nC
10nC
19nC
10nc
Qge
Vth(min)
4
3
C
Gon
RESoff
Qgc
82nC
20nC
Qgc
82nC
20nC
RESoff
sizing
OFF
Gon
ADVANCE DATA
flowing in R
Vge*
9V
9V
CRESoff
85pF
14pF
sizing
Vge*
9V
9V
tsw
400ns
200ns
dV/dt
CRESoff
85pF
14pF
Goff
Goff
RGoff
RGoff ? 4 Ω
RGoff ? 35 Ω
Iavg
0.25A
0.15A
Rtot
14
85
Translated into equations::
Rearranging the equation yields:
When R
Vcc/I
As an example, table 3 reports R
lar IGBT to withstand dV
NOTICE: the above-described equations are in-
tended being an approximated way for the gate
resistances sizing. More accurate sizing may
account more precise device modelling and para-
sitic component dependent on the PCB and
power section layout and related connections.
V
th
Rtot
24
40
O-
RGon
RTOT - RDRp = 6.5 Ω
RTOT - RDRp = 78 Ω
R
(I
R
Goff
IR2214/IR22141(SS)
Goff
O-
Goff
RGon
RTOT - RDRp = 12.7 Ω
RTOT - RDRp = 32.5 Ω
from IR2214 datasheet).
> 4 Ohm, R
std commercial value
C
R
RESoff
std commercial value
DRn
V
th
I
dV
dt
out
DRn
/dt = 5V/ns.
82 Ω
8.2 Ω
R
is well defined by
Goff
R
Goff
10 Ω
33 Ω
DRn
C
for two popu-
RESoff
R
dVout/dt
DRn
4.5V/ns
5V/ns
Tsw
420ns
202ns
dV
dt
out
25