©2007 Fairchild Semiconductor Corporation
1
www.fairchildsemi.com
October 2007
FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
FPF2180/82/83/84/86/87
Full Function Load Switch with Reverse Current Blocking
Features
1.8 to 5.5V Input Voltage Range
Controlled Turn-On
200mA and 400mA Current Limit Options
Undervoltage Lockout
Thermal Shutdown
<2A Shutdown Current
Auto Restart
Fast Current limit Response Time
5s to Moderate Over Currents
30ns to Hard Shorts
Fault Blanking
Reverse Current Blocking
Power Good Function
RoHS Compliant
Applications
PDAs
Cell Phones
GPS Devices
MP3 Players
Digital Cameras
Peripheral Ports
Hot Swap Supplies
General Description
The FPF2180/82/83/84/86/87 is a series of load switches which
provides full protection to systems and loads which may
encounter large current conditions. These devices contain a
55m current-limited P-channel MOSFET which can operate
over an input voltage range of 1.8-5.5V. Internally, current is
prevented from flowing when the MOSFET is off and the output
voltage is higher than the input voltage. Switch control is by a
logic input (ON) capable of interfacing directly with low voltage
control signals. Each part contains thermal shutdown protection
which shuts off the switch to prevent damage to the part when a
continuous over-current condition causes excessive heating.
When the switch current reaches the current limit, the part
operates in a constant-current mode to prohibit excessive
currents from causing damage. For the FPF2180/82/84/86, if
the constant current condition still persists after 30ms, the part
will shut off the switch and pull the fault signal pin (FLAGB) low.
The FPF2180/84 have an auto-restart feature which will turn the
switch on again after 450ms if the ON pin is still active. The
FPF2182/86 do not have this auto-restart feature so the switch
will remain off until the ON pin is cycled. For the FPF2183/87, a
current limit condition will immediately pull the fault signal pin
low and the part will remain in the constant-current mode until
the switch current falls below the current limit. The minimum
current limit is 200mA for the FPF2180/82/83 while that for the
FPF2184/86/87 is 400mA.
These parts are available in a space-saving 6 ball advanced.
Pb-Free 1 x 1.5 mm CSP package.
Ordering Information
Part Current Limit
[mA]
Current Limit
Blanking Time
[ms]
Auto-Restart
Time
[ms]
ON Pin
Activity Top Mark
FPF2180 200/300/400 15/30/60 225/450/900 Active HI A
FPF2182 200/300/400 15/30/60 NA Active HI B
FPF2183 200/300/400 0 NA Active HI C
FPF2184 400/600/800 15/30/60 225/450/900 Active HI D
FPF2186 400/600/800 15/30/60 NA Active HI E
FPF2187 400/600/800 0 NA Active HI F
BOTTOM TOP
Pin 1
PGOOD
V
IN
V
OUT
FLAGB
GND
ON
2
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Application Circuit
Functional Block Diagram
OFF ON ON
V
IN
GND
FPF2180/2/3/4/6/7
FLAGB
V
OUT
TO LOAD
PGOOD
UVLO
THERMAL
SHUTDOWN CURRENT
LIMIT
CONTROL
LOGIC
V
IN
ON
PGOOD
FLAGB
GND
REVERSE
CURRENT
BLOCKING
V
OUT
3
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Pin Configuration
Pin Description
Absolute Maximum Ratings
Recommended Operating Range
Electrical Characteristics
V
IN
= 1.8 to 5.5V, T
A
= -40 to +85°C unless otherwise noted. Typical values are at V
IN
= 3.3V and T
A
= 25°C.
Pin Name Function
C1 PGOOD Power Good output: Open drain output which indicate that output voltage has reached 90%
of input voltage
B2 V
IN
Supply Input: Input to the power switch and the supply voltage for the IC
B1 V
OUT
Switch Output: Output of the power switch
A1 FLAGB Fault Output: Active LO, open drain output which indicates an over current supply under
voltage or over temperature state.
C2 GND Ground
A2 ON ON Control Input
Parameter Min. Max. Unit
V
IN
, V
OUT
, ON, FLAGB, PGOOD to GND -0.3 6 V
Power Dissipation @ T
A
= 25°C (Note 1) 1.2 W
Operating Temperature Range -40 125 °C
Storage Temperature -65 150 °C
Thermal Resistance, Junction to Ambient 85 °C/W
Electrostatic Discharge Protection HBM 8000 V
MM 400 V
Parameter Min. Max. Unit
V
IN
1.8 5.5 V
Ambient Operating Temperature, T
A
-40 85 °C
Parameter Symbol Conditions Min. Typ. Max. Units
Basic Operation
Operating Voltage V
IN
1.8 5.5 V
Quiescent Current I
Q
I
OUT
= 0mA
V
ON
= V
IN
V
IN
= 1.8V 70
AV
IN
= 3.3V 75
V
IN
= 5.5V 85
On-Resistance R
ON
T
A
= 25°C, I
OUT
= 200mA 55 80 m
T
A
= -40 to +85°C, I
OUT
= 200mA 135
1.0 x 1.5 CSP Bottom View
A1
A2
B1
B2
C1C2
Note 1: Package power dissipation on 1square inch pad, 2 oz. copper board.
4
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Electrical Characteristics Cont.
V
IN
= 1.8 to 5.5V, T
A
= -40 to +85°C unless otherwise noted. Typical values are at V
IN
= 3.3V and T
A
= 25°C.
Parameter Symbol Conditions Min. Typ. Max. Units
ON Input Logic High Voltage (ON) V
IH
V
IN
= 1.8V 0.8 V
V
IN
= 5.5V 1.4
ON Input Logic Low Voltage V
IL
V
IN
= 1.8V 0.5 V
V
IN
= 5.5V 1.0
ON Input Leakage V
ON
= V
IN
or GND -1 0 1 A
V
IN
Shutdown Current V
ON
= 0V, V
IN
= 5.5V,
V
OUT
= short to GND -2 2 A
FLAGB Output Logic Low Voltage V
IN
= 5V, I
SINK
= 10mA 0.05 0.2 V
V
IN
= 1.8V, I
SINK
= 10mA 0.12 0.3
FLAGB Output High Leakage Current V
IN
= V
ON
= 5V 1 A
PGOOD Threshold Voltage 90 %
PGOOD Threshold Voltage
Hysteresis 1 %
PGOOD Output Logic Low Voltage V
IN
= 5V, I
SINK
= 10mA 0.05 0.2 V
V
IN
= 1.8V, I
SINK
= 10mA 0.12 0.3 V
PGOOD Output High Leakage
Current V
IN
= 5V, Switch ON 1 A
Reverse Block
V
OUT
Shutdown Current V
ON
= 0V, V
OUT
= 5.5V,
V
IN
= short to GND -2 2 A
Reverse Breakdown Voltage V
breakdown
V
IN
= V
ON
= 0V, I
OUT
= 200A 9 V
Protections
Current Limit I
LIM
V
IN
= 3.3V,
V
OUT
= 3.0V
FPF2180
FPF2182
FPF2183
200 300 400
mA
FPF2184
FPF2186
FPF2187
400 600 800
Thermal Shutdown
Shutdown Threshold T
J
increasing 140 °C
Return from Shutdown 130 °C
Hysteresis 10 °C
Under Voltage Lockout V
UVLO
V
IN
Increasing 1.55 1.65 1.75 V
Under Voltage Lockout Hysteresis 50 mV
Dynamic
Delay On Time td
ON
R
L
=500, C
L
=0.1F 20 s
V
OUT
Rise Time t
R
R
L
=500, C
L
=0.1F 20 s
Turn On Time t
ON
R
L
=500, C
L
=0.1F 40 s
Delay Off Time td
OFF
R
L
=500, C
L
=0.1F 15 s
V
OUT
Fall Time t
F
R
L
=500, C
L
=0.1F 110 s
Turn Off Time t
OFF
R
L
=500, C
L
=0.1F 125 s
Over Current Blanking Time t
BLANK
FPF2180, FPF2182, FPF2184,
FPF2186 15 30 60 ms
Auto-Restart Time t
RSTRT
FPF2180,FPF2184 225 450 900 ms
Short Circuit Response Time
V
IN
= V
ON
= 3.3V. Moderate
Over-Current Condition 5s
V
IN
= V
ON
= 3.3V. Hard Short 30 ns
5
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Characteristics
Figure 1. Quiescent Current vs. Input Voltage Figure 2. Quiescent Current vs. Input Voltage
Figure 4. V
ON
High Voltage vs. Input Voltage
Figure 5. V
ON
Low Voltage vs. Input Voltage Figure 6. Current Limit vs. Output Voltage
Figure 3. Quiescent Current vs. Temperature
-0.1
0.1
0.3
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1 2 3 4 5 6 7
S UP P L Y V O L T AG E (V )
SUPPLY CURRENT ( uA)
V
ON
=0V
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1 2 3 4 5 6
V
IN
, SUP PLY V O L T AG E (V)
V
ON
SUPPLY VOLTAGE ( V)
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1 2 3 4 5 6
V
IN
, SUPPLY VOLT AGE (V)
V
ON
SUPPLY VOLTAGE ( V)
V
ON L
(V
IL
)
50
55
60
65
70
75
80
85
90
95
100
105
110
-65 -40 -15 10 35 60 85 110 135
T
J
, J UNC T IO N T E M P E RAT URE (
o
C)
SUPPLY CURRENT ( uA)
V
IN
=1.8V
V
IN
=3.3V
V
IN
=5.5V
160
190
220
250
280
310
340
0123456
(V
IN
-V
OUT
), SUPPLY VOLTAGE(V)
ILIM, SUPPLY CURRENT (mA)
FPF2180/82/83
65
70
75
80
85
90
95
1 2 3 4 5 6 7
SUPPLY VOLTAGE (V)
SUPPLY CURRENT ( uA)
V
ON
=V
IN
6
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Characteristics
Figure 9. Current Limit vs. Temperature Figure 10. R
ON
vs. V
IN
Figure 11. R
ON
vs. Temperature Figure 12. T
ON
/ T
OFF
vs. Temperature
Figure 7. Current Limit vs. Output Voltage Figure 8. Current Limit vs. Temperature
565
570
575
580
585
590
595
600
-65 -40 -15 10 35 60 85 110 135
T
J
, JUNCTION TEMPERATURE (
o
C)
SUPPLY CURRENT ( mA)
FPF2184/86/87
350
400
450
500
550
600
650
0123456
(VIN
-VOUT), SUPPLY VOLTAGE(V)
ILIM, SUPPLY CURRENT (mA)
FPF2184/86/87
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
-65 -40 -15 10 35 60 85 110 135
TJ, JUNCTION TEMPERATURE (oC)
NORMALIZED
RON(mOhms)
V
IN
=1.8V
V
IN
=3.3V
V
IN
=5.5V
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1 2 3 4 5 6
V
IN
, SUPPLY VOLTAGE(V)
NORMALIZED
R
ON
(mOhms)
275
280
285
290
295
300
-65 -40 -15 10 35 60 85 110 135
T
J
, JUNCTION TEMPERATURE (
o
C)
SUPPLY CURRENT ( mA)
FPF2180/82/83
10
100
1000
-65 -40 -15 10 35 60 85 110 135
T
J
, JUNCTION TEM PERATURE (
o
C)
TURN-ON/OFF TIMES (mS)
Vin = 3.3V
RL = 500 Ohms
Cout = 0.1uF
T
ON
T
OFF
7
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Characteristics
Figure 15. T
BLANK
vs. Temperature Figure 16. T
ON
Response
Figure 17. T
OFF
Response Figure 18. Short Circuit Response Time
(Output shorted to ground)
Figure 13. T
RISE
/ T
FALL
vs. Temperature Figure 14. T
RESTART
vs. Temperature
V
IN
2V/DIV
I
OUT
10mA/DIV
C
IN
= 10F
C
OUT
= 0.1F
R
L
= 500
V
IN
= 3.3V
100s/DIV
V
ON
2V/DIV
V
OUT
2V/DIV
200s/DIV
C
IN
= 10F
C
OUT
= 0.1F
R
L
= 500
V
IN
= 3.3V
V
IN
2V/DIV
I
OUT
10mA/DIV
V
ON
2V/DIV
V
OUT
2V/DIV
20s/DIV
V
IN
2V/DIV
V
OUT
2V/DIV
C
IN
= 10F
V
IN
= 3.3V
I
OUT
5A/DIV
405
420
435
450
465
480
495
-65 -40 -15 10 35 60 85 110 135
TJ, JUNCTION TEMPERATURE (oC)
RESTART TIME(mS)
25
27
29
31
33
35
-65 -40 -15 10 35 60 85 110 135
TJ, JUNCTION TEMPERATURE (oC)
BLANKING TIME (mS)
1
10
100
1000
-65 -40 -15 10 35 60 85 110 135
T
J
, JUNCTION TEMPERATURE (
o
C)
RISE / FALL TIMES (mS)
T
FALL
T
RISE
Vin = 3.3V
RL = 0.5K
CL = 0.1uF
8
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Characteristics
Figure 23. T
BLANK
Response Figure 24. T
RESTART
Response
Figure 19. Current Limit Response Time
(Switch is powered to a short)
Figure 22. PGOOD ResponseFigure 21. Current Limit Response Time
(Output is loaded by 2.2, C
OUT
= 10F)
Figure 20. Current Limit Response Time
(Output is loaded by 2.2, C
OUT
= 0.1F)
C
IN
= 10F
V
IN
= V
ON
= 3.3V
V
OUT
= GND
V
IN
= V
ON
2V/DIV
I
OUT
500mA/DIV
50s/DIV
50s/DIV
100s/DIV
V
IN
2V/DIV
I
OUT
500mA/DIV
V
ON
2V/DIV
V
OUT
2V/DIV
C
IN
= 10F
V
IN
= V
ON
= 3.3V
C
OUT
= 0.1uF
V
IN
2V/DIV
I
OUT
500mA/DIV
V
ON
2V/DIV
V
OUT
2V/DIV
C
IN
= 10F
V
IN
= V
ON
= 3.3V
C
OUT
= 10uF
20s/DIV
C
IN
= 10F
C
OUT
= 0.1F
R
L
= 500
V
IN
= 5.5V
V
IN
5V/DIV
V
ON
5V/DIV
PGOOD
5V/DIV
V
OUT
5V/DIV
10ms/DIV
C
IN
= 10F
C
OUT
= 0.1F
V
DRV2
2V/DIV
V
OUT
2V/DIV
I
OUT
500mA/DIV
V
FLAGB
2V/DIV
T
BLANK
R
L
= 500
V
IN
= 3.3V
∆ = 4.5V
Note 2: V
DRV
signal forces the device to go into overcurrent condition by loading a 2.2 resistor.
V
DRV2
2V/DIV
V
OUT
2V/DIV
I
OUT
500mA/DIV
V
FLAGB
2V/DIV
T
RESTART
100ms/DIV
C
IN
= 10F
C
OUT
= 0.1F
R
L
= 500
V
IN
= 3.3V
9
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Typical Characteristics
Figure 25. Switch is turned on into a large output capacitor
1.Short circuit detection.
When the output voltage is below VSCTH=1.1V, the
current limit value is set at 62.5% of the current limit
value.
2. Current limit condition.
Due to the large charging current of the output capacitor
the load switch is still in the current limiting mode.
3. Normal operation.
Output current is below the current limit value
V
IN
2V/DIV
I
OUT
500mA/DIV
V
ON
2V/DIV
V
OUT
2V/DIV
C
IN
= 10F
C
OUT
= 150F
R
L
= 8.2
V
IN
= 3.3V
123
500s/DIV
10
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Description of Operation
The FPF2180/82/83/84/86/87 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
55m 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 preset for either 200mA or 400mA.
On/Off Control
The ON pin controls the state of the switch. Activating ON
continuously holds the switch in the on state so long as there is
no under-voltage on V
IN
or a junction temperature in excess of
140°C. ON is active HI and has a low threshold making it
capable of interfacing with low voltage signals. In addition,
excessive currents will cause the switch to turn off for FPF2180/
82 and FPF2184/86. The FPF2180/84 have an Auto-Restart
feature which will automatically turn the switch on again after
450ms. For the FPF2182/86, the ON pin must be toggled to
turn-on the switch again. The FPF2183/87 do not turn off in
response to a over current condition but instead remain operat-
ing in a constant 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 FPF2180/82/84/86, the FLAGB
goes LO at the end of the blanking time while FLAGB goes LO
immediately for the FPF2183/87. FLAGB remains LO through
the Auto-Restart Time for the FPF2180/84. For the
FPF2182/86, FLAGB is latched LO and ON must be toggled to
release it. With the FPF2183/87, 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
IN
and FLAGB. During shutdown, the
pull-down on FLAGB is disabled to reduce current draw from
the supply.
Current Limiting
The current limit guarantees that the current through the switch
doesn't exceed a maximum value while not limiting at less than
a minimum value. For the FPF2180/82/83 the minimum current
is 200mA and the maximum current is 400mA and for the
FPF2184/86/87 the minimum current is 400mA and the
maximum current is 800mA. The FPF2180/82/84/86 have a
blanking time of 30ms, 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
FPF2183/87 have no current limit blanking period so
immediately upon a current limit condition FLAGB is activated.
These parts will remain in a constant current state until the ON
pin is deactivated or the thermal shutdown turns-off the switch.
For preventing the switch from large power dissipation during
heavy load a short circuit detection feature is introduced. Short
circuit condition is detected by observing the output voltage.
The switch is put into short circuit current limiting mode if the
switch is loaded with a heavy load. When the output voltage
drops below VSCTH, short circuit detection threshold voltage,
the current limit value re-conditioned and short circuit current
limit value is decreased to 62.5% of the current limit value. This
keeps the power dissipation of the part below a certain limit
even at dead short conditions at 5.5V input voltage. The VSCTH
value is set to be 1V. At around 1.1V of output voltage the
switch is removed from short circuit current limiting mode and
the current limit is set to the current limit value.
Under-Voltage Lockout
The under-voltage lockout turns-off the switch if the input
voltage 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
externally generated excessive temperatures. During an
over-temperature condition the FLAGB is activated and the
switch is turned-off. The switch automatically turns-on again if
temperature of the die drops below the threshold temperature.
Reverse Current Blocking
The entire FPF2180/82/83/84/86/87 family has a Reverse
Current Blocking feature that protects input source against
current flow from output to input. For a standard USB power
design, this is an important feature which protects the USB host
from being damaged due to reverse current flow on V
BUS
.
When the load switch is OFF, no current flows from the output to
the input. If the switch is turned on and the output voltage is
greater than input voltage this feature is activated and turns off
the switch. This will prevent any current flow from output to
input. The reverse current blocking feature will be deactivated if
the V
OUT
- V
IN
is smaller than a typically 50mV threshold.
During this time some current (50mV/R
ON
) will flow from the
output to input until input voltage become greater than output
voltage. The FLAGB operation is independent of the Reverse
Current blocking and will not report a fault condition if this
feature is activated.
Timing Diagram
where:
td
ON
= Delay On Time
t
R
= V
OUT
Rise Time
t
ON
= Turn On Time
td
OFF
= Delay Off Time
t
F
= V
OUT
Fall Time
t
OFF
= Turn Off Time
V
ON
V
OUT
10%
10% 10%
90%
90%
90%
td
ON
t
R
t
ON
td
OFF
t
F
t
OFF
11
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FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Application Information
Typical Application
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
IN
and GND. A 0.1F ceramic capacitor, C
IN
, placed
close to the pins is usually sufficient. Higher values of C
IN
can
be used to further reduce the voltage drop.
Output Capacitor
A 0.1uF capacitor C
OUT
, should be placed between V
OUT
and
GND. This capacitor will prevent parasitic board inductances
from forcing V
OUT
below GND when the switch turns-off. For the
FPF2180/82/84/86, the total output capacitance needs to be
kept below a maximum value, C
OUT
(max), to prevent the part
from registering an over-current condition and turning-off the
switch. The maximum output capacitance can be determined
from the following formula,
Power Dissipation
During normal operation as a switch, the power dissipation is
small and has little effect on the operating temperature of the
part. The parts with the higher current limits will dissipate the
most power and that will only be,
If the part goes into current limit the maximum power dissipation
will occur when the output is shorted to ground. For the
FPF2180/84, the power dissipation will scale by the
Auto-Restart Time, t
RSTRT
, and the Over Current Blanking Time,
t
BLANK
, so that the maximum power dissipated is,
When using the FPF2182/86, attention must be given to the
manual resetting of the part. Continuously resetting the part at a
high duty cycle when a short on the output is present can cause
the temperature of the part to increase. The junction
temperature will only be allowed to increase to the thermal shut-
down threshold. Once this temperature has been reached, tog-
gling ON will not turn-on the switch until the junction
temperature drops. For the FPF2180/84, a short on the output
will cause the part to operate in a constant current state
dissipating a worst case power as calculated in (3) until the ther-
mal shutdown activates. It will then cycle in and out of thermal
shutdown so long as the ON pin is active and the short is
present.
Board Layout
For best performance, all traces should be as short as possible.
To be most effective, the input and output capacitors should be
placed close to the device to minimize the effects that parasitic
trace inductances may have on normal and short-circuit
operation. Using wide traces for V
IN
, V
OUT
and GND will help
minimize parasitic electrical effects along with minimizing the
case to ambient thermal impedance.
OFF ON ON
V
IN
GND
FPF2180/2/3/4/6/7
FLAGB
V
OUT
LOAD
Battery
1.8V-5.5V
C1 = 0.1F
R1 = 100K
C2 = 0.1F
R2 = 499
PGOOD
Typical value = 100K
Larger value of C1
is needed for long
supply traces.
C
OUT(max)
= I
LIM
(max) x t
BLANK
(min)
V
IN
(2)
(1)
P = (I
LIM
)
2
x R
ON
= (0.8)
2
x 0.055 = 35.2mW
12
www.fairchildsemi.com
FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Application Notes
Power good function in sequential startup. No battery is loaded to the output
Power Good
FPF218X family has a "Power Good" feature. PGOOD pin is an
open-drain MOSFET which asserts high when the output
voltage reaches 90% of the input voltage.
PGOOD pin requires an external pull up resistor that is
connected to the output voltage when there is no battery in the
load side and the logic level of the subsequent controller
permits. This would give logic levels similar to a CMOS output
stage for PGOOD, while still keeping the option to tie the pull-up
to a different supply voltage. A 100K is recommended to be
used as pull up resistor. The PGOOD pin status is independent
of the ON pin position. This mean that PGOOD pin stays low
when the load switch is OFF. If the Power Good feature is not
used in the application the pin can be connected directly to
GND.
Sequential Startup using Power Good
The power good pin can be connected to another load switch's
enable pin to implement sequential startup. PGOOD pin asserts
low when the load switch is OFF. This feature allows driving a
subsequent circuit. The diagram illustrates power good function
in sequential startup. As the VOUT1 of the first load switch
starts to ramp to the 90% of its input voltage the second switch
remains in OFF state. Whereas the VOUT1 passes the 90%
threshold, power good signal becomes active and asserts high.
This signal will turn on the second load switch and VOUT2 will
start to increase. The total startup time may vary according to
the difference between supply voltages that are used in the
application.
OFF ON ON
V
IN
GND
FPF218X
FLAGB
V
OUT
To Load
V
IN1
Startup Power Sequence
PGOOD
100K
ON
V
IN
GND
FPF218X
FLAGB
V
OUT
To Load
V
IN2
PGOOD
100K
13
www.fairchildsemi.com
FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Dimensional Outline and Pad Layout
14
www.fairchildsemi.com
FPF2180/82/83/84/86/87 Rev. F
FPF2180/82/83/84/86/87 Full Function Load Switch with Reverse Current Blocking
Rev. I31
TRADEMARKS
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is not intended to be an exhaustive list of all such trademarks.
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS
HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF
THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE
UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF
FAIRCHILD’S WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE
PRODUCTS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to result
in significant injury to the user.
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
PRODUCT STATUS DEFINITIONS
Definition of Terms
ACEx
®
Build it Now™
CorePLUS™
CROSSVOLT
™
CTL™
Current Transfer Logic™
EcoSPARK
®
Fairchild
®
Fairchild Semiconductor
®
FACT Quiet Series™
FACT
®
FAST
®
FastvCore™
FPS™
FRFET
®
Global Power Resource
SM
Green FPS™
Green FPS™ e-Series™
GTO™
i-Lo
™
IntelliMAX™
ISOPLANAR™
MegaBuck™
MICROCOUPLER™
MicroFET™
MicroPak™
MillerDrive™
Motion-SPM™
OPTOLOGIC
®
OPTOPLANAR
®
®
PDP-SPM™
Power220
®
Power247
®
POWEREDGE
®
Power-SPM™
PowerTrench
®
Programmable Active Droop™
QFET
®
QS™
QT Optoelectronics™
Quiet Series™
RapidConfigure™
SMART START™
SPM
®
STEALTH™
SuperFET™
SuperSOT™-3
SuperSOT™-6
SuperSOT™-8
SyncFET™
The Power Franchise
®
TinyBoost™
TinyBuck™
TinyLogic
®
TINYOPTO™
TinyPower™
TinyPWM™
TinyWire™
µSerDes™
UHC
®
UniFET™
VCX™
Datasheet Identification Product Status Definition
Advance Information Formative or In Design This datasheet contains the design specifications for product development.
Specifications may change in any manner without notice.
Preliminary First Production This datasheet contains preliminary data; supplementary data will be
published at a later date. Fairchild Semiconductor reserves the right to make
changes at any time without notice to improve design.
No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor reserves
the right to make changes at any time without notice to improve design.
Obsolete Not In Production This datasheet contains specifications on a product that has been
discontinued by Fairchild semiconductor. The datasheet is printed for
reference information only.