2SC0435T
Target
IGBT-Driver.com
Page 7
VDC terminal
The driver has one VDC terminal on the interface connector to supply the DC-DC converters for the secondary
sides.
VDC should be supplied with 15V. It is recommended to connect the VCC and VDC terminals to a common
+15V power supply. In this case the driver limits the inrush current at startup and no external current
limitation of the voltage source for VDC is needed.
MOD (mode selection)
The MOD input allows the operating mode to be selected with a resistor connected to GND.
Direct mode
If the MOD input is connected to GND, direct mode is selected. In this mode, there is no interdependence
between the two channels. Input INA directly influences channel 1 while INB influences channel 2. High level
at an input (INA or INB) always results in turn-on of the corresponding IGBT. In a half-bridge topology, this
mode should be selected only when the dead times are generated by the control circuitry so that each IGBT
receives its own drive signal.
Caution:
Synchronous or overlapping timing of both switches of a half-bridge basically shorts the DC link.
Half-bridge mode
If the MOD input is connected to GND with a resistor 71k<R
M
<181k, half-bridge mode is selected. In this
mode, the inputs INA and INB have the following functions: INA is the drive signal input while INB acts as the
enable input (see Fig. 5).
When input INB is low level, both channels are blocked. If it goes high, both channels are enabled and follow
the signal on the input INA. At the transition of INA from low to high, channel 2 turns off immediately and
channel 1 turns on after a dead time T
D
.
0V
-10V
+15V
+3.3...15V
Gate G1
INA
-10V
+15V
Gate G2
0V
+3.3...15V
Both channels OFF
Dead time (both channels OFF)
INB
Fig. 5 Signals in half-bridge mode
