15
Application Information
Product Overview Description
The ACPL-P343/W343 is an optically isolated power output
stage capable of driving IGBTs of up to 200 A and 1200 V.
Based on BCDMOS technology, this gate drive optocou-
pler delivers higher peak output current, better rail-to-rail
output voltage performance and two times faster speed
than the previous generation products.
The high peak output current and short propagation delay
are needed for fast IGBT switching to reduce dead time
and improve system overall e ciency. Rail-to-rail output
voltage ensures that the IGBT’s gate voltage is driven to
the optimum intended level with no power loss across
IGBT. This helps the designer lower the system power
which is suitable for bootstrap power supply operation.
It has very high CMR(common mode rejection) rating
which allows the microcontroller and the IGBT to operate
at very large common mode noise found in industrial
motor drives and other power switching applications. The
input is driven by direct LED current and has a hysteresis
that prevents output oscillation if insu cient LED driving
current is applied. This will eliminates the need of addi-
tional Schmitt trigger circuit at the input LED.
The stretched SO6 package which is up to 50% smaller
than conventional DIP package facilitates smaller more
compact design. These stretched packages are compliant
to many industrial safety standards such as IEC/EN/DIN EN
60747-5-2, UL 1577 and CSA.
Recommended Application Circuit
The recommended application circuit shown in Figure 28
illustrates a typical gate drive implementation using the
ACPL-P343. The following describes about driving IGBT.
However, it is also applicable to MOSFET. Designers will
need to adjust the V
CC
supply voltage, depending on the
MOSFET or IGBT gate threshold requirements (Recom-
mended V
CC
= 15 V for IGBT and 12 V for MOSFET).
The supply bypass capacitors (1 F) provide the large
transient currents necessary during a switching transition.
Because of the transient nature of the charging currents, a
low current (3.0 mA) power supply will be enough to power
the device. The split resistors (in the ratio of 1.5:1) across
the LED will provide a high CMR response by providing a
balanced resistance network across the LED.
The gate resistor RG serves to limit gate charge current
and controls the IGBT collector voltage rise and fall times.
In PC board design, care should be taken to avoid routing
the IGBT collector or emitter traces close to the ACPL-P343
input as this can result in unwanted coupling of transient
signals into ACPL-P343 and degrade performance.
_
V
EE
CATHODE
NC
ANODE
V
OUT
V
CC
_
R
R
+
1
2
3
6
5
4
R
g
+
V
CE
+ HVDC
-HVDC
3-HVDC
AC
1 MF
V
CC
= 15 V
V
EE
= 5 V
+
_
Q1
Q2
_
+
V
CE
_
+
_
Figure 28. Recommended application circuit with split resistors LED drive
