This preview shows page 1. Sign up to view the full content.
Unformatted text preview: corporate a unique
facility to disable output by using the ENABLE pin.
With the exception of the IXD_408, the ENABLE pin
is tied high internally. When this pin is driven LOW in
response to detecting an abnormal load current, the
Driver output enters its Tristate (High Impedance
State) mode and a soft turn-off of MOSFET/IGBT
can be achieved. This helps prevent damage that
could occur to the MOSFET/IGBT due to Ldi/dt over
voltage transient, if it were to be switched off
abruptly, “L” representing total inductance in series
with Drain or Collector. A suggested circuit to
accomplish this soft turn off upon detecting overload
or short circuit is shown in Fig. (2). It is also possible
to do this by an independent short circuit/overload
detect circuit, which could be a part of the PWM or
other controller IC. All one needs to do is to take IXAN0009 output signal (FAULT) from such a circuit and
feed it into the ENABLE pin of Driver. A resistor
R P connected across Gate and Source or Gate
and Emitter (as the case may be) would ensure
soft turn-off of the MOSFET/IGBT, turn-off time
being equal to RP(C GS + CGD)
4.2.1 LOW CURRENT DUAL IC DRIVERS
Fig. (11) shows an interesting application for a 4
Amp Dual driver IC in a Phase Shift PWM
Controller application, in which galvanic isolation
is obtained by using Gate Drive Transformers.
Note that this Controller operates at a fixed
frequency. Turn-off enhancement is achieved by
using local PNP transistors in secondary of gate
For a vast number of low and medium current
MOSFETs and IGBTs, 2 Amp to 4 Amp dual IC
drivers provide a convenient tool and circuit
simplicity, coupled with performance.
4.2.2 HIGH CURRENT IC DRIVERS
These are eminently suitable for driving higher
current MOSFETs and IGBTs and larger size
schematics applying these in various topologies
are possible and some of these are shown in
The 5 pin TO -263 surface mount version of
some IC drivers can be soldered directly...
View Full Document
This note was uploaded on 01/15/2014 for the course ECE 624 taught by Professor Staff during the Winter '08 term at Ohio State.
- Winter '08