ACPL-330J Datasheet, PDF (17/22 Pages) AVAGO TECHNOLOGIES LIMITED – Fault Feedback, Active Miller Clamp and Auto-Fault Reset

Application Information
Product Overview Description
The ACPL-330J is a highly integrated power control
device that incorporates all the necessary components
for a complete, isolated IGBT / MOSFET gate drive circuit
with fault protection and feedback into one SO-16
package. Active Miller clamp function eliminates the
need of negative gate drive in most application and
allows the use of simple bootstrap supply for high side
driver. An optically isolated power output stage drives
IGBTs with power ratings of up to 100 A and 1200 V. A
high speed internal optical link minimizes the propaga-
tion delays between the microcontroller and the IGBT
while allowing the two systems to operate at very large
common mode voltage differences that are common
in industrial motor drives and other power switching
applications. An output IC provides local protection
for the IGBT to prevent damage during over current,
and a second optical link provides a fully isolated fault
status feedback signal for the microcontroller. A built
in “watchdog” circuit, UVLO monitors the power stage
supply voltage to prevent IGBT caused by insufficient
gate drive voltages. This integrated IGBT gate driver is
designed to increase the performance and reliability of
a motor drive without the cost, size, and complexity of a
discrete design.
Two light emitting diodes and two integrated circuits
housed in the same SO-16 package provide the input
control circuitry, the output power stage, and two optical
channels. The output Detector IC is designed manufac-
tured on a high voltage BiCMOS/Power DMOS process.
The forward optical signal path, as indicated by LED1,
transmits the gate control signal. The return optical signal
path, as indicated by LED2, transmits the fault status
feedback signal.
Under normal operation, the LED1 directly controls the
IGBT gate through the isolated output detector IC, and
LED2 remains off. When an IGBT fault is detected, the
output detector IC immediately begins a “soft” shutdown
sequence, reducing the IGBT current to zero in a con-
trolled manner to avoid potential IGBT damage from
inductive over voltages. Simultaneously, this fault status
is transmitted back to the input via LED2, where the fault
latch disables the gate control input and the active low
fault output alerts the microcontroller.
During power-up, the Under Voltage Lockout (UVLO)
feature prevents the application of insufficient gate
voltage to the IGBT, by forcing the ACPL-330J’s output
low. Once the output is in the high state, the DESAT (V_CE)
detection feature of the ACPL-330J provides IGBT pro-
tection. Thus, UVLO and DESAT work in conjunction to
provide constant IGBT protection.
6, 7
D
ANODE
R
5, 8
I
CATHODE
V
LED1
E
R
2
V_CC1
3
FAULT
SHIELD
LED2
UVLO
DESAT
V_CLAMP
13
V_CC2
11
V_OUT
DESAT
14
9, 12
V_EE
10
V_CLAMP
V_E
16
1, 4
V_S
SHIELD
Figure 32. Block Diagram of ACPL-330J
15
V_LED
Recommended Application Circuit
The ACPL-330J has an LED input gate control, and an
open collector fault output suitable for wired ‘OR’ ap-
plications. The recommended application circuit shown
in Figure 33 illustrates a typical gate drive implementa-
tion using the ACPL-330J. The following describes about
driving IGBT. However, it is also applicable to MOSFET.
Depending upon the MOSFET or IGBT gate threshold
requirements, designers may want to adjust the VCC
supply voltage (Recommended V_CC = 17.5V for IGBT and
12.5V for MOSFET).
The two supply bypass capacitors (0.1 μF) provide the
large transient currents necessary during a switching
transition. Because of the transient nature of the
charging currents, a low current (5mA) power supply
suffices. The desaturation diode D_DESAT 600V/1200V
fast recovery type, t_rr below 75ns (e.g. ERA34-10) and
capacitor C_BLANK are necessary external components for
the fault detection circuitry. The gate resistor R_G serves to
limit gate charge current and controls the IGBT collector
voltage rise and fall times. The open collector fault
output has a passive pull-up resistor R_F (2.1 kΩ) and a
1000 pF filtering capacitor, C_F. A 47 kΩ pull down resistor
R_PULL-DOWN on V_OUT provides a predictable high level
output voltage (V_OH). In this application, the IGBT gate
driver will shut down when a fault is detected and fault
reset by next cycle of IGBT turn on. Application notes are
mentioned at the end of this datasheet.
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