FPF2500_07 FAIRCHILD [Fairchild Semiconductor], FPF2500_07 Datasheet - Page 10

• Manufacturer Part Number: FPF2500_07
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

FPF2500-FPF2506 Rev. D4
Application Information
Typical Application
Setting Current Limit
The FPF2500, FPF2501, and FPF2502 have a current limit
which is set with an external resistor connected between I
and GND. This resistor is selected by using the following
equation,
The following table can also be used to select R
application would be the 0.500A current that is required by a
single USB port. Using the table below an appropriate selection
for the R
port load could draw 0.525A, but not more than 0.875A.
Likewise for a dual port system, an R
always deliver at least 1.050A and never more than 1.750A.
Input Capacitor
To limit the voltage drop on the input supply caused by transient
in-rush currents when the switch turns-on into a discharged load
capacitor or a short-circuit, a capacitor needs to be placed
between V
close to the pins is usually sufficient. Higher values of C
be used to further reduce the voltage drop.
Battery
12V
Battery
12V
SET
IN
R
R
SET
resistor would be 12.4KΩ. This will ensure that the
and GND. A 0.1uF ceramic capacitor, C
SET
-
is in Ohms and I
=
12500
C1=10uF
C1=10uF
×
I
SET
OFF ON
OFF ON
SET
×
is in Amps
e
(
0.485
SET
5.5V max
5.5V max
of 34.8KΩ would
×
I
SET
SET
)
. A typical
IN
, placed
IN
V
ON
V
ON
FPF2500-FPF2502
FPF2503-FPF2506
IN
IN
SET
can
(1)
10
GND
GND
Current Limit Various R
R
[KΩ]
7.87
10.0
12.4
14.7
17.4
20.5
23.2
26.7
30.9
34.8
39.0
43.2
48.7
53.6
29.0
64.9
SET
FLAGB
V
V
ISET
OUT
OUT
Min. Current
0.375
0.450
0.525
0.600
0.675
0.750
0.825
0.900
0.975
1.050
1.125
1.200
1.275
1.350
1.425
1.500
Limit
RSET
[A]
5.5V max
R1=100KΩ
Typ. Current
SET
C2=1uF
C2=1uF
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1.200
1.300
1.400
1.500
1.600
1.700
1.800
1.900
2.000
Limit
[A]
Values
Max. Current
www.fairchildsemi.com
0.625
0.750
0.875
1.000
1.125
1.250
1.375
1.500
1.625
1.750
1.875
2.000
2.125
2.250
2.375
2.500
Limit
[A]
R2=240Ω
R2=240Ω