LTC4358 LINER [Linear Technology], LTC4358 Datasheet - Page 8

• Manufacturer Part Number: LTC4358
• Description: 5A Ideal Diode
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
V
In the event of an input short, parasitic inductance between
the input supply of the LTC4358 and the load bypass
capacitor may cause V
operating voltage. This causes the turn-off time (t
increase. To preserve the fast turn-off time, local output
bypassing of 39μF or more is suffi cient or a 100Ω, 0.1μF
RC hold-up circuit on the V
in Figure 2a and Figure 2b.
Layout Considerations
The following advice should be considered when laying out
a printed circuit board for the LTC4358: The OUT pin should
LTC4358
8
(a)
(b)
DD
V
V
IN
IN
Hold-Up Circuit
Figure 2. Two Methods of Protecting Against Collapse
of V
= 12V
= 12V
DD
From Input Short and Stray Inductance
IN
IN
DD
LTC4358
LTC4358
GND
GND
to glitch below its minimum
DD
pin can be used as shown
DRAIN
DRAIN
OUT
OUT
V
V
4358 F02
DD
DD
R1
100
C1
0.1 F
C
39 F
V
BYPASS
OUT
OFF
V
) to
OUT
be connected as closely as possible to the EXPOSED PAD
(drain of the MOSFET) for good accuracy. Keep the traces
to the IN and DRAIN wide and short. The PCB traces as-
sociated with the power path through the MOSFET should
have low resistance. See Figure 4.
The DRAIN acts as a heatsink to remove the heat from the
device. For a single layer PCB with the DFN package, use
Figure 5 to determine the PCB area needed for a speci-
fi ed maximum current and ambient temperature. If using
a two sided PCB, the maximum current is increased by
10%. If the FE package is used, the maximum current is
increased by 4%.
V
MMBD1205
IN
= 12V
Figure 3. –12V Reverse Input Protection
IN
LTC4358
GND
DRAIN
OUT
V
DD
4358 F03
R1
100Ω
C1
0.1μF
V
12V
5A
OUT
C
LOAD
4358fa