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Features
!
!
!
1.8 to 5.5V Input Voltage Range
Typical R
ON
= 75m Ω at IN = 5.5V
1.3A Current Limit (Typical)
!
!
Slew Rate Controlled
Reversed Current Blocking when Disabled
!
!
ESD Protected, Above 4000V HBM
Independent Thermal Shutdown
!
!
UVLO
RoHS Compliant
Applications
!
Notebook Computing
!
!
Peripheral USB Ports
Networking / USB Based Equiptment
June 2009
FPF2300/02/03
Dual-Output Current Limit Switch
Description
The FPF2300/02/03 are dual-channel load switches of
IntelliMAX™ family. The FPF2300/02/03 consist of dual, independent, current-limited, slew rate controlled, Pchannel MOSFET power switches. Slew rated turn-on prevents inrush current from glitching supply rails. The input voltage range operates from 1.8V to 5.5V to fulfill today's USB device supply requirements. Switch control is accomplished by a logic input (ON) capable of interfacing directly with low-voltage control signal.
For the FPF2302, if the constant current condition persists after 10ms, these parts shut down the switch and pull the fault signal pin (FLAGB) LOW. The FPF2300 has an auto-restart feature that turns the switch on again after 504ms if the ON pin is still active. For the FPF2303, a current limit condition immediately pulls the fault signal pin LOW and the part remains in the constant-current mode until the switch current falls below the current limit.
For the FPF2300 through FPF2303, the current limit is typically 1.3A for each switch to align with notebook computing applications. FPF2300/02/03 is available in both SO8 and MLP 3X3mm 8-lead packages.
Figure 1. 8-Lead SOP Figure 2. 8-Lead MLP (3x3mm)
Ordering Information
Part Number
FPF2300MX
FPF2302MX
FPF2303MX
Minimum
Current
Limit
1100mA
1100mA
1100mA
FPF2300MPX 1100mA
FPF2302MPX 1100mA
FPF2303MPX 1100mA
Current Limit
Blanking Time
10ms
10ms
0ms
10ms
10ms
0ms
Eco
Status
Auto
Restart
ON Pin
Activity
Mode Package
RoHS 504ms Active LOW Restart 8-Lead SO8
RoHS
RoHS
Green
Green
Green
N/A
N/A
504
N/A
N/A
Active LOW Latch Off 8-Lead SO8
Active LOW
Constant
Current
8-Lead SO8
Active LOW
Active LOW Latch Off
Active LOW
Restart
Constant
Current
8-Lead Molded Leadless Package (MLP)
8-Lead Molded Leadless Package (MLP)
8-Lead Molded Leadless Package (MLP)
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html
.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
www.fairchildsemi.com
Application Circuit
IN = 1.8V-5.5V
C
IN
OFF ON
OFF ON
IN
FLAGB(A)
FLAGB(B)
ONA
FPF2300/2/3
OUTA
ONB
GND
OUTB
C
OUTB
Figure 3. Typical Application
Functional Block Diagram
IN
UVLO
ONA CONTROL
LOGIC A
REVERSE
CURRENT
BLOCKING
CURRENT
LIMIT A
THERMAL
PROTECTION A
TO LOAD A
TO LOAD B
C
OUTA
OUTA
FLAGB(A)
ONB CONTROL
LOGIC B
THERMAL
PROTECTION B
CURRENT
LIMIT B
REVERSE
CURRENT
BLOCKING
OUTB
FLAGB(B)
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
GND
Figure 4. Block Diagram
2 www.fairchildsemi.com
Pin Configuration
GND 1
IN 2
ONA
ONB
3
4
SO8
8 FLAGB(A)
7 OUTA
6 OUTB
5 FLAGB(B)
FLAGB(A) 8
OUTA 7
OUTB 6
FLAGB(B) 5
9
1 GND
2 IN
3 ONA
4 ONB
MLP 3X3mm 8-Lead Bottom View
Figure 5. Pin Configurations
Pin Description
Pin #
1
2
3
4
5
6
7
8
9(MLP)
Name
GND
IN
ONA
ONB
FLAGB(B)
OUTB
OUTA
FLAGB(A)
Thermal Pad
Function
Ground
Supply Input: Input to the power switch and the supply voltage for the IC.
ON / OFF control input of power switch A. Active LOW
ON / OFF control input of power switch B. Active LOW
Fault Output B, Active LO, open drain output which indicates an over supply, UVLO and thermal shutdown.
Switch Output: Output of the power switch B
Switch Output: Output of the power switch A
Fault Output A, Active LO, open drain output which indicates an over supply, UVLO and thermal shutdown.
IC Substrate, which can be connected to GND for better thermal performance. Do not connect to other pins.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
3 www.fairchildsemi.com
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only .
Symbol Parameter
IN, OUTA, OUTB, ONA, ONB, FLAGB(A), FLAGB(B) to GND
P
D
T
STG
Θ
JA
ESD
Power Dissipation
Storage Temperature
Thermal Resistance, Junction-to-Ambient
Electrostatic Discharge Protection
SO8
MLP
SO8
MLP
Human Body Model, JESD22-A114
Charged Device Model, JESD22-C101
Min.
Max.
Unit
-0.3
-65
6.0
0.8
1.4
0.6
2.2
+150
158
92
216
57
V
W
°C
°C/W
4000
2000
V
Notes:
1.
Two-layer PCB of 2s0p from JEDEC STD 51-3.
2.
Four-layer PBD of 2s0p from JEDEC STD 51-7.
3.
Soldered thermal pad on a two-layer PCB without vias based on JEDEC STD 51-3.
4.
Soldered thermal pad on a four-layer with two vias connected with GND plane base on JEDEC STD 51-5, 7.
Recommended Operating Range
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings.
Symbol Parameter
IN
T
A
Supply Input
Ambient Operating Temperature
Min.
Max.
Unit
1.8
-40
5.5
+85
V
°C
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
4 www.fairchildsemi.com
Electrical Characteristics
IN = 1.8 to 5.5V, T
A
= -40 to +85°C unless otherwise noted. Typical values are at IN = 3.3V and T
A
= 25°C.
Symbol Parameter Conditions Min. Typ. Max. Units
Basic Operation
V
IN
I
Q
Operating Voltage
Quiescent Current
I
R
I
SD
V
V
ON
IH
IL
ON
IN Shutdown Current
IN = 5.5V, V
ONA
= V
ONB
= 0V, I
OUT
= 0mA
V
ONA
= V
ONB
= 5.5V, IN = 5.5V
OUTA = OUTB = Short to GND,
On Resistance
IN = 5.5V, I
OUT
= 200mA, T
A
= 25°C
IN = 5.5V, I
OUT
= 200mA, T
A
= -40°C to 85°C
IN = 1.8V
ON Input Logic High Voltage (ON)
IN = 5.5V
IN = 1.8V
ON Input Logic Low Voltage
IN = 5.5V
ON Input Leakage V
ON
= IN or GND
IN = 5.5V, I
SINK
= 1mA
FLAGB Output Logic Low Voltage
IN = 1.8V, I
SINK
= 1mA
FLAGB Output High Leakage Current IN = V
ON
= 5V
Protections
I
LIM
Current Limit
TSD Thermal Shutdown
IN = 3.3V, V
OUTA
= V
OUTB
= 3V, T
A
= 25°C
Shutdown Threshold
Return from Shutdown
Hysteresis
IN Increasing V
UVLO
V
UVLO_HYS
Dynamic
Under-Voltage Shutdown
Under-Voltage Shutdown Hysteresis
1.8
0.8
1.4
-1
5.5
52.5
94.5
75
90
3
140
0.5
0.9
0.1
1
0.2
0.15
0.30
1
1.1
1.3
140
130
10
1.5
1.55
1.65
1.75
50
V
μA
μA mΩ
V
V
μA
V
μA
A
°C
V mV t
ON t
OFF t
R t
BLANK t
RSTRT_BLANK t
RSRT t
CLR
Turn-On Time
Turn-Off Time
OUTA, OUTB Rise Time
Over-Current Blanking Time
Startup FLAGB Blanking Time
Auto-Restart Time
Current Limit Response Time
R
L
= 500Ω, C
L
= 0.1μF
R
L
= 500Ω
R
L
= 500Ω, C
L
= 0.1μF
FPF2300, FPF2302
FPF2303
FPF2300
IN = 3.3V, Moderate Over-Current Condition
5
5
113.5
6
13.5
10
10
504
20
20
20
μs
μs
μs ms ms ms
μs
Note:
5.
FPF2303 has a 10ms startup FLAGB blanking time when the part is turned on via the ON pin to ensure transient load currents settle.
90% 90%
OUT
10% 10% t
R t
F
ON 50% 50%
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
OUT
90%
10% t
DON t
DOFF t
ON
= t
R
+ t
DON t
OFF
= t
F
+ t
DOFF
Figure 6. Timing Diagram
5 www.fairchildsemi.com
Typical Characteristics
70.00
ONA = ONB = 0V
60.00
85°C
50.00
25°C
40.00
-40°C
30.00
20.00
10.00
0.00
1.8
2.2
2.5
2.9
3.3
3.7
4.0
SUPPLY VOLTAGE (V)
4.4
4.8
5.1
5.5
Figure 7. Quiescent Current vs. Supply Voltage
70.00
ONA = ONB = 0V
60.00
IN = 5.5V
50.00
40.00
30.00
20.00
10.00
0.00
-40 -15
IN = 3.3V
10
IN = 1.8V
35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 8. Quiescent Current vs. Temperature
85
5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
-40
IN = ONA = ONB = 5.5V
OUT = 0V
-15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 9. IN Shutdown Current vs. Temperature
85
160
150
140
130
120
110
100
90
80
70
60
1.8
R
ON
A
R
ON
B
2.2
2.5
2.9
3.3
3.7
4.0
4.4
SUPPLY VOLTAGE (V)
ONA = ONB = 0V
I
OUT
T
A
= 200mA
= 25°C
4.8
5.1
5.5
Figure 10. R
ON
vs. Supply Voltage (MLP)
160
150
140
130
120
110
100
90
80
70
60
1.8
R
ON
A
R
ON
B
2.2
2.5
2.9
3.3
3.7
4.0
4.4
SUPPLY VOLTAGE (V)
ONA = ONB = 0V
I
OUT
T
A
= 200mA
= 25°C
4.8
5.1
5.5
Figure 11. R
ON
vs. Temperature (SO8)
100
95
90
85
80
75
70
65
60
55
50
-40
IN = 5.5V
I
OUT
= 200mA
ONA = ONB = 0V
-15
R
R
ON
ON
B
A
10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 12. R
ON vs. Temperature (MLP)
85
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
6 www.fairchildsemi.com
Typical Characteristics
90
85
IN = 5.5V
I
OUT
= 200mA
ONA = ONB = 0V
80
75
70
65
60
55
50
-40 -15
R
R
ON
ON
B
A
10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 13. R
ON
vs. Temperature (SO8)
1.5
T
A
= 25°C
1.3
1.0
0.8
0.5
0.3
V
IL
V
IH
85
0.0
1.8
2.2
2.5
2.9
3.3
3.7
4.0
SUPPLY VOLTAGE (V)
4.4
4.8
5.1
5.5
Figure 14. ON Threshold Voltage vs. Supply Voltage
1.2
1.0
0.8
0.6
IN = 5.5V
IN = 3.3V
IN = 1.8V
0.4
0.2
0.0
-40 -15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 15. ON High Voltage vs. Temperature
85
1.2
1.0
0.8
0.6
0.4
IN = 5.5V
IN = 3.3V
IN = 1.8V
0.2
0.0
-40 -15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 16. ON Low Voltage vs. Temperature
85
1350
1340
1330
1320
T
A
= 25°C
1310
1300
1290
1280
1270
1260
1250
1.8
2.2
ILIM(Typ)A
ILIM(Typ)B
2.5
2.9
3.3
3.7
4.0
SUPPLY VOLTAGE (V)
4.4
4.8
5.1
5.5
Figure 17. Current Limit vs. Supply Voltage
1350
1340
1330
1320
1310
1300
1290
1280
1270
1260
1250
-40
IN = 3.3V
OUTA = OUTB = 3V
ONA = ONB = 0V
-15
ILIM(Typ)A
10
ILIM(Typ)B
35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 18. Current Limit vs. Temperature
85
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
7 www.fairchildsemi.com
Typical Characteristics
1000
100 t
DON
IN = 3.3V
R
L
= 500 Ohms
C
L
= 0.1 uF
10 t
DOFF
IN = 3.3V
R
L
= 500 Ohms
1
-40 -15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 19. t
DON
/ t
DOFF
vs. Temperature
85
20
18
16
14
12
10
8
6
4
2
0
-40 t
R t
F
IN = 3.3V
R
L
= 500 Ohms
C
L
= 0.1 uF
IN = 3.3V
R
L
= 500 Ohms
-15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 20. t
RISE
/ t
FALL
vs. Temperature
85
11.0
10.5
10.0
9.5
9.0
8.5
8.0
7.5
7.0
-40
FLAGB(A)
FPF2300/2
IN = 3.3V
ONA = ONB = 0V
FLAGB(B)
-15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 21. t
BLANK
vs. Temperature
85
10.0
9.5
9.0
FPF2303
IN = 3.3V
ONA = ONB = 0V
FLAGB(A)
8.5
8.0
7.5
FLAGB(B)
7.0
-40 -15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 22. t
RSTRT_BLANK
vs. Temperature
85
620.0
600.0
580.0
FPF2300
IN = 3.3V
ONA = ONB = 0V
OUTA
560.0
540.0
520.0
OUTB
500.0
-40 -15 10 35
T
J
, JUNCTION TEMPERATURE (°C)
60
Figure 23. t
RSTRT
vs. Temperature
85
IN
2V/DIV
ON
2V/DIV
OUT
2V/DIV
IN = 5V
ON = 3.3V
C
OUT
R
L
= 0.1μF
= 500Ω
200μs/DIV
Figure 24. t
ON
Response
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
8 www.fairchildsemi.com
Typical Characteristics
IN
2V/DIV
ON
2V/DIV
OUT
2V/DIV
200μs/DIV
Figure 25. t
OFF
Response
IN = 5V
ON = 3.3V
C
OUT
R
L
= 0.1μF
= 500Ω
IN = 5V
C
OUT
R
L
= 10μF
= 2.8Ω
ON
2V/DIV t
BLANK
FLAGB
2V/DIV
I
OUT
1A/DIV
OUT
5V/DIV
2ms/DIV
Figure 26. Over-Current Blanking Time (FPF2300/2)
ON
2V/DIV
FLAGB
2V/DIV
I
OUT
1A/DIV
OUT
2V/DIV t
START_BLANK
C
OUT
R
L
= 10μF
= 3.3Ω
2ms/DIV
Figure 27. Startup FLAGB Blanking Time (FPF2303)
ON
2V/DIV t
RSTRT
FLAGB
2V/DIV
I
OUT
1A/DIV
OUT
5V/DIV
IN = 5V
C
OUT
R
L
= 10μF
= 2.8Ω
100ms/DIV
Figure 28. Auto-Restart Time (FPF2300)
IN
5V/DIV
ON
5V/DIV
IN = 5V
ON = 3.3V
R
L
= 5Ω
C
OUT
= 470μF
I
OUT
1A/DIV
C
OUT
= 47μF
C
OUT
= 220μF
C
OUT
= 100μF
200μs/DIV
Figure 29. Current Limit at Startup with
Different Output Capacitor
IN
5V/DIV
ON
5V/DIV
OUT
5V/DIV
IN = 5V
ON = 3.3V
R
L
= 5Ω
C
OUT
= 47μF
C
OUT
= 100μF
C
OUT
= 220μF
C
OUT
= 470μF
200μs/DIV
Figure 30. Output Voltage at Startup with
Different Output Capacitor
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
9 www.fairchildsemi.com
Typical Characteristics
IN
5V/DIV
ON
2V/DIV
OUTA
2V/DIV
OUTB
2V/DIV
IN = 5V
ON = 3.3V
C
OUTA
C
OUTB
R
LA
= 100μF
= 100μF
= R
LB
= 1Ω
400μs/DIV
Figure 31. Current Limit Response Time Both
Channels are in OC
IN
5V/DIV
ON
2V/DIV
FLAGB(A)
2V/DIV
FLAGB(B)
2V/DIV
IN = 5V
ON = 3.3V
C
OUTA
C
OUTB
R
LA
= 100μF
= 100μF
= R
LB
= 1Ω
10ms/DIV
Figure 32. Startup FLAGB Blanking Time
IN
5V/DIV
ON
5V/DIV
I
OUT
500mA/DIV
OUT
5V/DIV
IN = 5V
C
OUT
C
L
R
L
= 47μF
= 470μF
= 5Ω
1ms/DIV
Figure 33. Inrush Response During Capacitive Load
Hot Plug-In Event
IN
5V/DIV
ON
5V/DIV
I
OUT
2A/DIV
OUT
5V/DIV
IN = 5V
C
IN
= 10μF
C
OUT
C
L
= 100μF
= 47μF
200μs/DIV
Figure 34. Inrush Response During Capacitive and
Resistive Load Hot Plug-In Event
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
10 www.fairchildsemi.com
Description of Operation
The FPF2300, FPF2302, and FPF2303 are dual-output currentlimit switches designed to meet notebook computer, peripheral
USB port, and point-of-load (POL) application power requirements.
Dual-output current can be used where dual or quad USB ports are powered by hosts or self-powered hubs. The FPF230X family offers control and protection while providing optimum operation current for a safe design practice. The core of each switch is a typical 75mΩ (IN = 5.5V) P-channel MOSFET and a controller capable of functioning over an input operating range of 1.8-5.5V.
The FPF230X family offers current limiting, UVLO (under-voltage lockout), and thermal shutdown protection per each switch. In the event of an over-current condition, the load switch limits the load to current limit value. The minimum current limit is set to 1100mA.
On/Off Control
The ON pin is active LOW for FPF2300/2/3 and controls the state of the switch. Pulling the ON pin continuous to LOW holds the switch in the ON state. The switch moves into the OFF state when the ON pin is pulled HIGH or if a fault is encountered. 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 FPF2300 and FPF2302 after a 10ms blanking time. The
FPF2300 has an auto-restart feature that automatically turns the switch ON again after 504ms. For the FPF2302, the ON pin must be toggled to turn on the switch again. The FPF2303 does not turn off in response to an over-current condition, but remains 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. FPF230X family has dual-output load switches being housed in one package. The minimum current at which both switches start limiting the load current is set to 1100mA. The
FPF2300 and FPF2302 have a blanking time of 10ms (typical), during which the switch acts as a constant current source. At the end of the blanking time, the switch is turned off. The FPF2303 has no current limit blanking period, so it remains in a constant current state until the ON pin of the affected switch is deactivated or the thermal shutdown turns off the switch.
Fault Reporting
Over-current, input under-voltage, and over-temperature fault conditions are signaled out by the FLAGB pin going LOW. A UVLO fault is reported on both FLAGB(A) and FLAGB(B) simultaneously, while over-current and over-temperature condition faults are reported independently. FPF2300 and FPF2302 have a current fault blanking feature that prevents over-current faults shorter than the blanking time (t
BLANK(Typ) signal (FLAGB) output.
= 10ms) from triggering the fault
If the over-current condition persists beyond the blanking time, the
FPF2300 pulls the FLAGB pin LOW and shuts the switch off. If the
ON pin is kept active, an auto-restart feature releases the FLAGB pin and turns the switch on again after a 504ms auto-restart time
(t
RSTRT
). If the over-current condition persists beyond the blanking time, the FPF2302 has a latch-off feature that pulls the FLAGB pin
LOW and shuts the switch off. The switch is kept off and the
FLAGB pin kept LOW until the ON pin is toggled. The FPF2303 responds to an overload condition by immediately pulling the
FLAGB pin LOW and the switch remains in constant current mode until the output overload condition is removed. The FPF2303 has a startup blanking feature that prevents current faults related to startup transients from triggering the FLAGB output. The startup blanking feature is effective for the first 10ms (typical) following device turn-on via ON pin.
.
The FLAGB outputs are two open-drain MOSFETs that require a pull-up resistor on each FLAGB pin. FLAGB can be pulled HIGH to a voltage source other than input supply with maximum 5.5V. A
100KΩ pull-up resistor is recommended. When the ON pin is inactive, the FLAGB is disabled to reduce current draw from the supply.
If the FLAGB is not used, the FLAGB can be connected to ground on the PCB.
ON device wakeup
IN device wakeup
FLAGB
RISE
TIME
90% V
OUT
OUT
10% V
OUT
I
LOAD
I
LIMIT
Figure 35. FLAGB Assertion in Under-Voltage Fault
ON
VIN
VOUT
ILOAD
RL* ILMIT
ILIMIT
Over current condtion
FLAGB tRSTRT tBLANK
Figure 36. FPF2300 FLAGB Reports While Entering into an Over-Current Condition
Note:
6.
An over-current condition signal loads the output with a heavy load current larger than I
LIM
value.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
11 www.fairchildsemi.com
ON
VIN
VOUT
ILOAD
ILIMIT
Thermal Shut down
Devic e C ools O ff automatically turns on again. To avoid unwanted thermal oscillations, a 10°C (typical) thermal hysteresis is implemented between thermal shutdown entry and exit temperatures.
If output of both switches are connected together and an excessive load current activates thermal protection of both, the controller can shut down the switches after both FLAGB outputs go LOW and turn on both channels again. This provides simultaneous switch turn on. Thermal protection is for device protection and should not be used as regular operation.
Over current condtion
FLAGB
Startup tBLANK
Figure 37. FPF2300 FLAGB While and Over-Current
Condition is Applied
Note:
7.
An over-current condition signal loads the output with a heavy load current larger than I
LIMIT
value.
Under-Voltage Lockout (UVLO)
The under-voltage lockout feature turns off the switch if the input voltage drops below the under-voltage lockout threshold.
With the ON pin active (ON pin pulled LOW), the input voltage rising above the under-voltage lockout threshold causes a controlled turn-on of the switch and limits current overshoot. If a device is in UVLO condition, both FLAGBs go LOW and indicate the fault condition. The device detects the UVLO condition when input voltage goes below UVLO voltage, but remains above
1.3V (typical).
Reverse Current Blocking
Each switch of FPF2300/2/3 has an independent 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 that protects the USB host from being damaged due to reverse current flow on V
BUS
. To activate the reverse current blocking, the switch must be in OFF state (ON pins inactivated) so that no current flows from the output to the input. The FLAGB operation is independent of the reverse current blocking and does not report a fault condition if this feature is activated.
Thermal Shutdown
The thermal shutdown protects the device from internally or externally generated excessive temperatures. Each switch has an individual thermal shutdown protection function and operates independently as adjacent switch temperatures increase above
140°C. If one switch is in normal operation and shutdown protection of second switch is activated, the first channel continues to operate if the affected channel's heat stays confined. The over-temperature in one channel can shut down both switches due to rapidly generated excessive load currents resulting in very high power dissipation. Generally, a thermally improved board layout can provide heat sinking and allow heat to stay confined and not affect the second switch operation.
During an over-temperature condition, the FLAGB is pulled
LOW and the affected switch is turned off. If the temperature of the die drops below the threshold temperature, the switch
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
12
Input Capacitor
To limit the voltage drop on the input supply caused by transient inrush currents when the switch is turned on into discharged load capacitors or a short-circuit; an input capacitor, C
IN
, is recommended between IN and GND. The FPF2310/2/3/3L features a fast current limit response time of 20μs. An inrush current (also known as surge current) could occur during the current limit response time while the switch is responding to an over-current condition caused by large output capacitors. A
10μF ceramic capacitor, C
IN
, is required to provide charges for the inrush current and prevent input voltage drop at turn on.
Higher values of C
IN
can be used to further reduce voltage drop.
Output Capacitor
A 0.1μF to 1μF capacitor, C
OUT
, should be placed between the
OUT and GND pins. This capacitor prevents parasitic board inductances from forcing output voltage below GND when the switch turns off. This capacitor should have a low dissipation factor. An X7R MLCC (Multilayer Ceramic Chip) capacitors is recommended.
For the FPF2300 and FPF2302, 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 beyond the blanking time and shutdown. The maximum output capacitance for a giving input voltage can be determined from the following:
C
OUT(MAX)
=
I
LIM(MIN)
x t
BLANK(MIN) (1)
V
IN
For example, in a 5V application, C
OUT(MAX) as:
can be determined
C
OUT(MAX)(IN = 5V)
=
1.1A x 5ms
5
(2)
= 1.1mF
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Application Information
10K Ω
10K Ω
Downstream
USB Port
33μF
Host
5V
1μF
OFF ON
OFF ON
IN
FLAGB(A)
FLAGB(B)
ONA
FPF2300/2/3
OUTA
ONB
GND
OUTB
33μF
Downstream
USB Port
Downstream
USB Port
33μF
Downstream
USB Port
33μF
Figure 38. Self Powered 4-Port USB Hub Using a Single FPF230X
FPF230X is designed to simplify USB port power design based on self-powering USB host/hub applications. A self-powering
USB port is powered by a local 5V power supply, not by an upstream port. Each port should supply at least 500mA to each downstream function based on USB 2.0 specification. Implementation can depend on the number of USB ports and current capability per port required in actual power designs. FPF230X has 1.1A minimum current limit per output, which can cover two ports, as shown in Figure 38. Four USB ports can be implemented with a single FPF230X part and current limiting is provided based on a two-port basis for a cost-effective solution.
Host
5V
1μF
1μF
OFF ON
OFF ON
OFF ON
OFF ON
10K Ω
10K Ω
IN
FLAGB(A)
FLAGB(B)
ONA
FPF2300/2/3
OUTA
ONB
GND
OUTB
10K Ω
10K Ω
IN
FLAGB(A)
FLAGB(B)
ONA
FPF2300/2/3
OUTA
ONB
GND
OUTB
33μF
33μF
33μF
33μF
Downstream
USB Port
Downstream
USB Port
Downstream
USB Port
Downstream
USB Port
Figure 39. Individual Port Power Management for Self-Powered 4-Port USB Hub
In Figure 39, each USB port is connected with each output.
Four USB ports can be implemented with two FPF230X parts.
Current limiting and control are provided based on a single port.
Current capability per port has more headroom; up to a minimum of 1.1A per port.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
13 www.fairchildsemi.com
Host
5V
1μF
OFF ON
OFF ON
10K Ω
10K Ω
IN
FLAGB(A)
FLAGB(B)
ONA
FPF2300/2/3
OUTA
ONB
GND
OUTB
33μF
Downstream
USB Port
Figure 40. Self-Powered USB Port for High Current Demand
High current, over 2A, is sometimes required to supply enough power to downstream functions. As shown in Figure 40, a 2.2A
minimum load current can be achieved by tying dual outputs together.
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:
P
D_MAX(Normal Operation)
= 2 x (I
LIM(MIN)
)
2
x R
ON(MAX) (3)
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:
P
D_MAX(Normal Operation)(IN = 5V)
= 2 x (1.1) 2 x 0.14
(4)
= 338mW
The maximum junction temperature should be limited to 125°C under normal operation. Junction temperature can be calculated using the formula below:
T
J
= P
D x R
θJA
+ T
A
(5) where:
T
J
is junction temperature;
P
D
is power dissipation across the switch;
R
θJA
T
A
is thermal resistance junction to ambient of the package;
is ambient temperature.
For the example, T
J(MAX)(Normal operation) with T
A calculated as:
for an SO8 package
=25°C while both switches are delivering up to 1.1A is
T
J(MAX)(NormalOperation)
= P
D_MAX(Normal Operation)(IN = 5V)
x 125 + 25
(6)
= 78.4°C
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
BLANK
FPF2300 is::
RSTRT
, and the over-current blanking time,
. In this case, the maximum power dissipated for the t
BLANK
P
D_MAX(CurrentLimit)
= 2 x t
BLANK
+ t
RSTRT x IN
(MAX)
x I
LIM(MAX)
(7) which results in:
P
D_MAX(CurrentLimit)
= 2 x
10
10 + 504 x 5.5 x 1.5 = 321mW (8)
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 drops below the thermal shutdown exit 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:
P
MAX
= 2 x IN
(MAX) x I
LIM(MAX)
= 2 x 5.5 x1.5 = 16.5 W (9)
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.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
14 www.fairchildsemi.com
PCB Layout Recommendations
For the 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 shortcircuit operation. Using wide traces for IN, OUTs, and GND pins helps minimize parasitic electrical effects and the case-toambient thermal impedance.
Improving Thermal Performance
Improper layout could result in higher junction temperature and triggering the thermal shutdown protection feature. This concern is particularly significant for the FPF2303, where both channels operate in constant current mode in the overload conditions and during fault condition the outputs are shorted, resulting in large voltage drop across switches. In this case, power dissipation of the switch (P
D
= (V
IN
- V
OUT
) x I
LIM(MAX)
) could exceed the maximum absolute power dissipation of part.
The following techniques improve the thermal performance of this family of devices. These techniques are listed in order of the significance of impact.
1.
Thermal performance of the load switch can be improved by connecting the DAP (Die Attach Pad) of MLP 3x3mm package to the GND plane of the PCB.
2.
Embedding two exposed through-hole vias into the DAP
(pin 9) provides a path for heat to transfer to the back GND plane of the PCB. A drill size of round, 15 mils (0.4mm), with 1-ounce copper plating is recommended to create appropriate solder reflow. A smaller size hole prevents the solder from penetrating into the via, resulting in device liftup. Similarly, a larger via hole consumes excessive solder and may result in voiding of the DAP.
Figure 42. Proper Layout of Output and Ground
Copper Area
15mil
25mil
Figure 41. Two Through-Hole Open Vias Embedded in DAP
3.
The IN, OUTs, and GND pins dissipate most of the heat
generated during a high load current condition. Figure 42
illustrates a proper layout for devices in MLP 3x3mm packages. IN, OUTs, and GND pins are connected to adequate copper so heat may be transferred as efficiently as possible out of the device. The low-power FLAGB and
ON pin traces may be laid out diagonally from the device to maximize the area available to the ground pad. Placing the input and output capacitors as close to the device as possible also contributes to heat dissipation, particularly during high load currents.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
15 www.fairchildsemi.com
FPF230X Evaluation Board
The FPF230X evaluation board has components and circuitry to demonstrate FPF2300/2/3 load switch functions and features, accommodating both the MLP 3x3mm and SO8 packages. The state of the each channel can be configured using J1 and J2 jumpers. In addition, both channels can be controlled by ONA and ONB test pints. Thermal performance of the board is improved using techniques in the layout recommendations section. R3 and R4 resistors are used on the board to sink a light load current when switches are activated.
Figure 44. Bottom and ASB Layers
Figure 43. Top, SST and AST Layers
(MLP 3x3mm and SO8)
Figure 45. Zoom-In to Top Layer
Releated Resources
FPF2300/02/03 Evaluation Board User Guide; Power Switch for USB Applications
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
16 www.fairchildsemi.com
Dimensional Outline and Pad Layout
Figure 46. 8-Lead SO8 Package
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
17 www.fairchildsemi.com
Dimensional Outline and Pad Layout
Figure 47. 8-Lead Molded Leadless Package (MLP)
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings: http://www.fairchildsemi.com/packaging/.
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
18 www.fairchildsemi.com
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Auto-SPM™
Build it Now™
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CTL™
Current Transfer Logic™
EcoSPARK
®
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EZSWITCH™*
™*
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FPS™
®
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FACT Quiet Series™
FACT
FAST
®
®
FastvCore™
FETBench™
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®
*
®
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®
Global Power Resource SM
Green FPS™
Green FPS™ e-Series™
Gmax™
GTO™
IntelliMAX™
ISOPLANAR™
MegaBuck™
MICROCOUPLER™
MicroFET™
MicroPak™
MillerDrive™
MotionMax™
Motion-SPM™
OPTOLOGIC
®
OPTOPLANAR
®
®
PDP SPM™
Power-SPM™
PowerTrench
PowerXS™
®
Programmable Active Droop™
QFET
®
QS™
Quiet Series™
RapidConfigure™
™
SmartMax™
SMART START™
SPM
®
STEALTH™
SuperFET™
SuperSOT™-3
SuperSOT™-6
SuperSOT™-8
SupreMOS™
SyncFET™
Sync-Lock™
®
*
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®
®
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®
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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
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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 a significant injury of the user.
2. A critical component in 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.
ANTI-COUNTERFEITING POLICY
Fairchild Semiconductor Corporation's Anti-Counterfeiting Policy. Fairchild's Anti-Counterfeiting Policy is also stated on our external website, www.fairchildsemi.com, under Sales Support.
Counterfeiting of semiconductor parts is a growing problem in the industry. All manufacturers of semiconductor products are experiencing counterfeiting of their parts. Customers who inadvertently purchase counterfeit parts experience many problems such as loss of brand reputation, substandard performance, failed applications, and increased cost of production and manufacturing delays. Fairchild is taking strong measures to protect ourselves and our customers from the proliferation of counterfeit parts. Fairchild strongly encourages customers to purchase Fairchild parts either directly from Fairchild or from Authorized
Fairchild Distributors who are listed by country on our web page cited above. Products customers buy either from Fairchild directly or from Authorized Fairchild
Distributors are genuine parts, have full traceability, meet Fairchild's quality standards for handling and storage and provide access to Fairchild's full range of up-to-date technical and product information. Fairchild and our Authorized Distributors will stand behind all warranties and will appropriately address any warranty issues that may arise. Fairchild will not provide any warranty coverage or other assistance for parts bought from Unauthorized Sources. Fairchild is committed to combat this global problem and encourage our customers to do their part in stopping this practice by buying direct or from authorized distributors.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification Product Status
Advance Information Formative / In Design
Preliminary
No Identification Needed
Obsolete
First Production
Full Production
Not In Production
© 2009 Fairchild Semiconductor Corporation
FPF2300/02/03 • Rev. 1.1.3
Definition
Datasheet contains the design specifications for product development. Specifications may change in any manner without notice.
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.
Datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve the design.
Datasheet contains specifications on a product that is discontinued by Fairchild Semiconductor.
The datasheet is for reference information only.
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