IGD508E/IGD515E
Data Sheet & Application Manual
Page 9
Layout of the terminals
The terminal pins of the drive modules in
the IGD series are configured so that the
layout can be kept simple. A spacing of
45 mm is maintained between the supply
pins and the power potential!
Note
In the following, the abbreviation "FOL"
will be used for the term "fiber-optic link".
This refers to a component of an FOL
connection, such as a fiber-optic
transmitter, a fiber-optic receiver or the
entire FOL connection consisting of the
fiber-optic transmitter, fiber-optic wire
and fiber-optic receiver.
Pins 1,2,3,4,9 and 10
GND and Vcc
These pins are used for the power supply
of the driver module. The nominal feed
voltage is between 12 V and 15 V. To
ensure reliable starting of the integrated
DC/DC converter, a switching-resistant
and low-inductance electrolytic capacitor
must be placed in the immediate vicinity
of Pins 9 and 10. The capacitance of this
capacitor must not be less than that of the
capacitor connected to Cs (Pin 23). The
current consumption of the DC/DC
converter is determined by the number of
driven transistors, their gate capacitance
and by the clock frequency.
Thanks to the high isolation of the feed
terminals with respect to all other pins, the
drivers of the IGD series can be supplied
by a potential of any size.
The internal turn-on thresholds are
designed so that 12-V operation is also
possible. This is particularly useful for
operating transistors that have very high
short-circuit currents at higher gate
voltages (low saturation types).
It should be noted that the drivers
themselves are not protected against self-
overload. A short circuit between the gate
and the emitter terminal, caused by a
defective power semiconductor, for
example, can lead to thermal destruction
of the driver.
Pin 25 - Output Gate
Pin 25 is the driver output for driving the
gate. Driving is from ±12 V to ±15 V,
depending on the supply voltage, but also
without a negative gate voltage
depending on the application and the
power transistors used (see description of
Pin 24, COM).
The output stages of the drivers of the IGD
series are very ruggedly dimensioned. The
maximum permissible gate charging
current is ±8 A for the IGD508Ex and
±15 A for the IGD515Ex; this allows the
largest IGBT and power MOSFET modules
to be driven. A number of power modules
connected in parallel can also be driven
directly. The charging current must be
limited by an external gate resistor. It
should be noted that when the gate is
driven with a ± voltage, the total voltage
rise (twice 12 to 15 V) must be
considered.
The gate of the power transistor must be
connected to Pin 25 by means of a lead
of minimum length. A gate circuit with two
gate resistors and a diode can be used to
set the switching speeds at turn-on and at