FPF2310 View Datasheet(PDF) - Fairchild Semiconductor
Part Name
Description
Manufacturer
FPF2310 Datasheet PDF : 17 Pages
| |||
Description of Operation
The FPF2310/2/3/3L are dual-output current-limit switches
designed to meet notebook computer, peripheral USB port, and
point-of-load (POL) application power requirements. Dual-output
current can be used where two USB ports are powered by hosts
or self-powered hubs. The FPF231X family offers control and
protection while providing optimum operation current for safe
design practices. The core of each switch is a 75mΩ (IN = 5.5V)
P-channel MOSFET and a controller capable of functioning over
an input operating range of 1.8 to 5.5V. The FPF231X offers
current limiting, UVLO (under-voltage lockout), and thermal
shutdown protection in each switch. In the event of an over-
current condition, the load switch limits the load to current limit
value. The current limit value for each switch can be adjusted
through the ISET pins. 400mA-600mA is adjustable for the
FPF2310 through FPF2313. The minimum current limit is
400mA-600mA with 10% accuracy at +25°C with minimum
variation over temperature.
On/Off Control
The ON pin is active HIGH for FPF2310/2/3 and controls the
state of the switch. Pulling the ON pin continuous to HIGH holds
the switch in ON state. The switch moves into the OFF state
when the ON pin is pulled LOW or if a fault is encountered.
FPF2313L is active LOW and performs in reverse order. For all
versions, an under-voltage on input voltage or a junction
temperature in excess of 140°C overrides the ON control to turn
off the switch. In addition, excessive currents cause the switch to
turn off in the FPF2310 and FPF2312 after 10ms blanking time.
The FPF2310 has an auto-restart feature that automatically turns
the switch ON again after 150ms. For the FPF2312, the ON pin
must be toggled to turn on the switch again. The FPF2313 and
FPF2313L do not turn off in response to an over-current
condition, but remain operating in a constant-current mode as
long as ON is enabled and the thermal shutdown or UVLO is not
activated. The ON pin does not have a pull-down or pull-up
resistor and should not be left floating.
Current Limiting
The current limit ensures that the current through the switch
doesn't exceed a maximum value, while not limiting at less than a
minimum value. FPF231X family has dual-output load switches in
one package. The current limit of each switch is adjustable
through the an external resistor connected to the ISET pin. The
current limit range is from 400mA to 600mA with 10% current limit
tolerance.
The FPF2310 and FPF2312 have a blanking time of 10ms
(tBLANK(Typ) = 10ms) during which the switch acts as a constant
current source.
If the over-current condition persists beyond the blanking time,
the FPF2310 latches off and shuts the switch off. If the ON pin is
kept active, an auto-restart feature releases the switch and turns
the switch on again after a 150ms auto-restart time (tRSTRT). If
the over-current condition persists beyond the blanking time, the
FPF2312 has a latch-off feature that shuts the switch off. The
switch is kept off until the ON pin is toggled. The FPF2313/3L
have no current-limit blanking period, so remain in a constant-
current state until the ON pin of the affected switch is deactivated
or the thermal shutdown turns off the switch.
ON
VIN
VOUT
ILOAD
Over
current
condtion
tBLANK
RL*ILMIT
tRSTRT
ILIMIT
Figure 33. FPF2310 Performance While Entering into
an Over-Current Condition.
Note:
3. An over-current condition signal loads the output with a
heavy load current larger than ILIM value.
ON
VIN
VOUT
ILOAD
ILIMIT
Thermal Shutdown
Device Cools Off
Over
current
condtion
Figure 34. FPF2313 Performance While Entering into
an Over-Current Condition
Note:
4 An over-current condition signal loads the output with a
heavy load current larger than ILIM value.
© 2009 Fairchild Semiconductor Corporation
FPF2310/12/13/13L • Rev. 1.1.3
11
www.fairchildsemi.com
Share Link: 