FPF2000_05 FAIRCHILD [Fairchild Semiconductor], FPF2000_05 Datasheet - Page 9

• Manufacturer Part Number: FPF2000_05
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

FPF2000-FPF2007 Rev. D
Description of Operation
The FPF2000-FPF2007 are current limited switches that protect
systems and loads which can be damaged or disrupted by the
application of high currents. The core of each device is a 0.7Ω
P-channel MOSFET and a controller capable of functioning over
a wide input operating range of 1.8-5.5V. The controller protects
against system malfunctions through current limiting, under-
voltage lockout and thermal shutdown. The current limit is pre-
set for either 50mA or 100mA.
On/OffControl
The ON pin controls the state of the switch. Active HI and LO
versions are available. Refer to the Ordering Information for
details. Activating ON continuously holds the switch in the on
state so long as there is no fault. For all versions, an under-volt-
age on VIN or a junction temperature in excess of 150°C over-
rides the ON control to turn off the switch. In addition, excessive
currents will cause the switch to turn off in FPF2000-FPF2002
and FPF2004-FPF2007. The FPF2000, FPF2001, FPF2004
and FPF2005 have an Auto-Restart feature which will automati-
cally turn the switch on again after 80ms. For the FPF2002 and
FPF2006, the ON pin must be toggled to turn-on the switch
again. The FPF2003 and FPF2007 do not turn off in response to
a over current condition but instead remain operating in a con-
stant current mode so long as ON is active and the thermal
shutdown or under-voltage lockout have not activated.
Fault Reporting
Upon the detection of an over-current, an input under-voltage,
or an over-temperature condition, the FLAGB signals the fault
mode by activating LO. For the FPF2000-FPF2002 and
FPF2004-FPF2006, the FLAGB goes LO at the end of the
blanking time while FLAGB goes LO immediately for the
FPF2003 and FPF2007. FLAGB remains LO through the Auto-
Restart Time for the FPF2000, FPF2001 FPF2004 and
FPF2005. For the FPF2002 and FPF2006, FLAGB is latched
LO and ON must be toggled to release it. With the FPF2003 and
FPF2007, FLAGB is LO during the faults and immediately
returns HI at the end of the fault condition. FLAGB is an open-
drain MOSFET which requires a pull-up resistor between V
and FLAGB. During shutdown, the pull-down on FLAGB is dis-
abled to reduce current draw from the supply.
Ordering Information
FPF2000
FPF2001
FPF2002
FPF2003
FPF2004
FPF2005
FPF2006
FPF2007
Part
Current Limit
[mA]
100
100
100
100
50
50
50
50
Blanking Time
Current Limit
[ms]
10
10
10
10
10
10
0
0
IN
9
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. For the FPF2000-FPF2003 the minimum cur-
rent is 50mA and the maximum current is 100mA and for the
FPF2004-FPF2007 the minimum current is 100mA and the
maximum current is 200mA. The FPF2000-FPF2002 and the
FPF2004-FPF2006, have a blanking time of 10ms, nominally,
during which the switch will act as a constant current source. At
the end of the blanking time, the switch will be turned-off and
the FLAGB pin will activate to indicate that current limiting has
occurred. The FPF2003 and FPF2007 have no current limit
blanking period so immediately upon a current limit condition
FLAGB is activated. These parts will remain in a constant cur-
rent state until the ON pin is deactivated or the thermal shut-
down turns-off the switch.
Reverse Voltage
If the voltage at the V
curents may flow and can cause permanent damage to the
device. FPF2000-FPF2007 is designed to control current flow
from V
Under-Voltage Lockout
The under-voltage lockout turns-off the switch if the input volt-
age drops below the under-voltage lockout threshold. With the
ON pin active the input voltage rising above the under-voltage
lockout threshold will cause a controlled turn-on of the switch
which limits current over-shoots.
Thermal Shutdown
The thermal shutdown protects the die from internally or exter-
nally generated excessive temperatures. During an over-tem-
perature condition the FLAGB is activated and the switch is
turned-off. The switch automatically turns-on again if tempera-
ture of the die drops below the threshold temperature.
Auto-Restart
IN
to V
Time
[ms]
NA
NA
NA
NA
80
80
80
80
OUT
.
OUT
pin is larger than the V
Activity
Active LO
Active LO
ON Pin
Active HI
Active HI
Active HI
Active HI
Active HI
Active HI
Top Mark
www.fairchildsemi.com
IN
200
201
202
203
204
205
206
207
pin, large