FDMF3030 FAIRCHILD [Fairchild Semiconductor], FDMF3030 Datasheet - Page 15

• Manufacturer Part Number: FDMF3030
• Description: Extra-Small, High-Performance, High-Frequency, DrMOS Module
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

© 2012 Fairchild Semiconductor Corporation
FDMF3030 • Rev. 1.0.0
Application Information
Supply Capacitor Selection
For the supply inputs (V
capacitor is recommended to reduce noise and to
supply the peak current. Use at least a 1µF X7R or X5R
capacitor. Keep this capacitor close to the VCIN pin and
connect it to the GND plane with vias.
Bootstrap Circuit
The bootstrap circuit uses a charge storage capacitor
(C
of 100nF X7R or X5R capacitor is usually adequate. A
series bootstrap resistor may be needed for specific
applications to improve switching noise immunity. The
boot resistor may be required when operating above
15V
MOSFET turn-on slew rate and V
values from 0.5Ω to 3.0Ω are typically effective in
reducing VSWH overshoot.
BOOT
IN
), as shown in Figure 31. A bootstrap capacitance
Open -
Drain
Output
PWM
Input
OFF
and is effective at controlling the high-side
DISB#
V
5V
ON
A
I
5V
C
VDRV
CIN
Figure 31.
), a local ceramic bypass
ZCD_END#
DISB#
THWN#
PWM
SHW
VDRV
FDMF3030
CGND
FDMF 6705
R
overshoot. R
VCIN
Circuit Diagram and Power Loss Measurement
VCIN
PGND
C
BOOT
VCIN
PHASE
VSWH
BOOT
VIN
15
R
BOOT
VCIN Filter
The VDRV pin provides power to the gate drive of the
high-side and low-side power MOSFET. In most cases,
it can be connected directly to VCIN, the pin that
provides power to the logic section of the driver. For
additional noise immunity, an RC filter can be inserted
between the VDRV and VCIN pins. Recommended
values would be 10Ω and 1µF.
Power Loss and Efficiency
Measurement and Calculation
Refer to Figure 31 for power loss testing method.
Power loss calculations are:
P
P
P
P
P
EFFI
EFFI
IN
SW
OUT
LOSS_MODULE
LOSS_BOARD
C
=(V
=V
VIN
=V
MODULE
BOARD
V V
C
IN
SW
BOOT
OUT
A
I
IN
x I
SW
x I
=100 x P
IN
x I
=100 x P
=P
OUT
) + (V
=P
OUT
L
IN
OUT
V
IN
(W)
- P
IN
(W)
- P
5V
OUT
OUT
SW
SW
C
x I
OUT
/P
/P
5V
(W)
(W)
IN
) (W)
IN
(%)
(%)
I
OUT
A
V
OUT
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