FPF2300MPX Fairchild Semiconductor, FPF2300MPX Datasheet - Page 14

• Manufacturer Part Number: FPF2300MPX
• Description: IC LOAD SW 2CH RESTART 8-MLP
• Manufacturer: Fairchild Semiconductor
• Series: IntelliMax™r
• Type: High Side Switchr

Specifications of FPF2300MPX

• Number Of Outputs: 2
• Rds (on): 140 mOhm
• Internal Switch(s): Yes
• Current Limit: 1.3A
• Voltage - Input: 1.8 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: FPF2300MPXTR

© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
High current, over 2A, is sometimes required to supply enough
power to downstream functions. As shown in Figure 40, a 2.2A
Power Dissipation
During normal operation as a switch, the power dissipation of
the device is small and has little effect on the operating
temperature of the part. The maximum power dissipation for
both switches while the switch is in normal operation occurs just
before both channels enter into current limit. This may be
calculated using the formula:
For example, for a 5V application, maximum normal operation
power loss while both switches delivering output current up to
1.1A, can be calculated as:
The maximum junction temperature should be limited to 125°C
under normal operation. Junction temperature can be calcu-
lated using the formula below:
where:
For the example, T
with T
calculated as:
T
= 78.4°C
T
P
R
T
J(MAX)(NormalOperation)
P
A
J
D
θJA
D_MAX(Normal Operation)
is junction temperature;
P
is ambient temperature.
is power dissipation across the switch;
T
A
D_MAX(Normal Operation)(IN = 5V)
J
is thermal resistance junction to ambient of the package;
=25°C while both switches are delivering up to 1.1A is
= P
= P
Host
5V
D
D_MAX(Normal Operation)(IN = 5V)
x R
θJA
J(MAX)(Normal operation)
+ T
1μF
A
= 2 x (I
Figure 40. Self-Powered USB Port for High Current Demand
LIM(MIN)
OFF ON
OFF ON
=
= 2 x (1.1)
338mW
)
2
for an SO8 package
x 125 + 25
x R
2
ON(MAX)
x 0.14
(4)
(5)
IN
ONA
ONB
(6)
(3)
FPF2300/2/3
14
minimum load current can be achieved by tying dual outputs
together.
If the part goes into current limit, the maximum power
dissipation occurs when the output of switch is shorted to
ground. For the FPF2300 the power dissipation scales with the
auto-restart time, t
t
FPF2300 is::
which results in:
Note that this is below the maximum package power dissipation
and the thermal shutdown feature protection provides additional
safety to protect the part from damage due to excessive
heating. The junction temperature is only able to increase to the
thermal shutdown threshold. Once this temperature has been
reached, toggling ON has no affect until the junction
temperature
temperature. For the FPF2303, a short on both outputs causes
both switches to operate in a constant current state and
dissipate a worst-case power of:
As both FPF2303 outputs are connected to GND.
This power dissipation is significant and activates both thermal
shutdown blocks and the part can cycle in and out of thermal
shutdown as long as the ON pin is activated (pulled LOW) and
the output short is present.
BLANK
P
GND
P
P
D_MAX(CurrentLimit)
D_MAX(CurrentLimit)
MAX
FLAGB(A)
FLAGB(B)
. In this case, the maximum power dissipated for the
= 2 x IN
10KΩ
10KΩ
OUTB
OUTA
drops
(MAX)
RSTRT
=
=
x I
2 x
2 x
below
LIM(MAX)
, and the over-current blanking time,
t
BLANK
33μF
10 + 504
t
10
BLANK
the
= 2 x 5.5 x1.5 = 16.5 W
+ t
RSTRT
x 5.5 x 1.5 = 321mW
thermal
Downstream
x IN
USB Port
(MAX)
shutdown
www.fairchildsemi.com
x I
LIM(MAX)
exit
(8)
(7)
(9)