2SC0435T
Description and Application Manual
Page 8
INTELLIGENT POWER ELECTRONICS
The value of the dead time T
D
is determined by the value of the resistor R
m
according to the following formula
(typical value):
7
.
52
]
[
5
.
31
]
[
+
⋅
=
Ω
s
T
k
R
D
M
μ
where 0.6
μ
s<
T
D
<4.1
μ
s and 72k
Ω
<
R
M
<182k
Ω
INA, INB (channel drive inputs, e.g. PWM)
INA and INB are basically drive inputs, but their function depends on the MOD input (see above). They safely
recognize signals in the whole logic-level range between 3.3V and 15V. Both input terminals feature Schmitt-
trigger characteristics (refer to the driver data sheet /3/). An input transition is triggered at any edge of an
incoming signal at INA or INB.
SO1, SO2 (status outputs)
The outputs SOx have open-drain transistors. When a fault condition (primary side supply undervoltage,
secondary side supply undervoltage, IGBT short-circuit or overcurrent) is detected, the corresponding status
output SOx goes to low (connected to GND). Otherwise, the output has high impedance.
The maximum SOx current in a fault condition should not exceed the value specified in the driver data sheet
/3/.
Both SOx outputs can be connected together to provide a common fault signal (e.g. for one phase). However,
it is recommended to evaluate the status signals individually to allow fast and precise fault diagnosis.
How the status information is processed
a) A fault on the secondary side (detection of short-circuit of IGBT module or supply undervoltage) is
transmitted to the corresponding SOx output immediately. The SOx output is automatically reset
(returning to a high impedance state) after a blocking time T
B
has elapsed (refer to “TB (input for
adjusting the blocking time T
B
) for timing information).
b) A supply undervoltage on the primary side is indicated to both SOx outputs at the same time. Both SOx
outputs are automatically reset (returning to a high impedance state) when the undervoltage on the
primary side disappears.
TB (input for adjusting the blocking time T
B
)
The terminal TB allows the blocking time to be set by connecting a resistor R
B
to GND (see Fig. 4). The
following equation calculates the value of R
B
connected between pins TB and GND in order to program the
desired blocking time T
B
(typical value):
51
]
[
0
.
1
]
[
+
⋅
=
Ω
ms
T
k
R
B
B
where
20ms<T
B
<130ms and 71k
Ω
<R
B
<181k
Ω
The blocking time can also be set to a minimum of 9µs (typical) by selecting R
B
=0
Ω
. The terminal TB must not
be left floating.
Note: It is also possible to apply a stabilized voltage at TB. The following equation is used to calculate the
voltage V
B
between TB and GND in order to program the desired blocking time T
B
(typical value):
02
.
1
]
[
02
.
0
]
[
+
⋅
=
ms
T
V
V
B
B
where 20ms<T
B
<130ms and 1.42<V
B
<3.62V
