FAN7392 Fairchild Semiconductor, FAN7392 Datasheet - Page 15

• Manufacturer Part Number: FAN7392
• Description: The FAN7392 is a monolithic high- and low-side gate drive IC, that can drive high-speed MOSFETs and IGBTs that operate up to +600V
• Manufacturer: Fairchild Semiconductor

FAN7392 Rev. 1.0.3
© 2009 Fairchild Semiconductor Corporation
The FAN7392 has a negative V
curve, as shown in Figure 38.
Even though the FAN7392 has been shown able to han-
dle these negative V
recommended that the circuit designer limit the negative
V
to minimized the value of parasitic elements and compo-
nent use. The amplitude of negative V
portional to the parasitic inductances and the turn-off
speed, di/dt, of the switching device.
General Guidelines
Printed Circuit Board Layout
The relayout recommended for minimized parasitic ele-
ments is as follows:
S
Direct tracks between switches with no loops or devia-
tion.
Avoid interconnect links. These can add significant
inductance.
Reduce the effect of lead-inductance by lowering
package height above the PCB.
Consider co-locating both power switches to reduce
track length.
To minimize noise coupling, the ground plane should
not be placed under or near the high-voltage floating
side.
To reduce the EM coupling and improve the power
switch turn-on/off performance, the gate drive loops
must be reduced as much as possible.
transient as much as possible by careful PCB layout
Figure 38. Negative V
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
0
100
200
300
S
tranient conditions, it is strongly
Pulse Width [ns]
400
S
Transient Chracteristic
500
S
600
transient performance
700
S
voltage is pro-
800
900 1000
15
Placement of Components
The recommended placement and selection of compo-
nent as follows:
It is stongly recommended that the placement of compo-
nents is as follows:
Place a bypass capacitor between the V
pins. A ceramic 1µF capacitor is suitable for most
applications. This component should be placed as
close as possible to the pins to reduce parasitic ele-
ments.
The bypass capacitor from V
the low-side driver and bootstrap capacitor recharge.
A value at least ten times higher than the bootstrap
capacitor is recommended.
The bootstrap resistor, R
sizing the bootstrap resistance and the current devel-
oped during initial bootstrap charge. If the resistor is
needed in series with the bootstrap diode, verify that
V
use is typically 5 ~ 10Ω that increase the V
constant. If the votage drop of of bootstrap resistor
and diode is too high or the circuit topology does not
allow a sufficient charging time, a fast recovery or
ultra-fast recovery diode can be used.
The bootstrap capacitor, C
capacitor, such as ceramic capacitor.
Place components tied to the floating voltage pins (V
and V
the device and the FAN7392. NC (not connected) pins
in this package maximize the distance between the
high-voltage and low-voltage pins (see Figure 5).
Place and route for bypass capacitors and gate resis-
tors as close as possible to gate drive IC.
Locate the bootstrap diode, D
ble to bootstrap capacitor, C
The bootstrap diode must use a lower forward voltage
drop and minimal switching time as soon as possible
for fast recovery or ultra-fast diode.
B
does not fall below COM (ground). Recommended
S
) near the respective high-voltage portions of
BOOT
BOOT
BOOT
CC
, must be considered in
BOOT
, uses a low-ESR
to COM supports both
.
, as close as possi-
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DD
BS
and V
time
SS
B