SmartSwitch
TM
General Description
The AAT4680 Electronic Resettable Fuse is part of
the AnalogicTech Application Specific Power MOS-
FET (ASPMTM) line of products. It is a 1A current
limited P-channel MOSFET power device that
remains fully enhanced as long as the input power
supply is above an under voltage lockout thresh-
old, and the load is below the current limit setting.
If the load increases above the current limit setting,
as is the case during a short circuit, the MOSFET
effectively becomes a constant current source
equal to the current limit. If the current limit condi-
tion persists long enough to heat the MOSFET to
an extreme temperature, the device will thermal
cycle off and on until the current limit condition is
removed. An open drain FAULT flag signals an
over current or over temperature condition.
Quiescent current is typically a low 10A.
The AAT4680 is available in a 5
-pin SOT-23, spec-
ified over a -40 to 85C temperature range.
Features
500mA steady state load current
600mA minimum current limit trip point
Low quiescent current, typically 10A
Over temperature protection
Fast transient response:
< 1s response to short circuit
400m
typical R
DS(ON)
Undervoltage Lockout
Temp range -40 to 85C
FAULT flag with 3ms blanking
5
-pin SOT23 package
Applications
USB ports
Peripheral ports
Desktop PCs
Cell phone ports
AAT4680
Electronic Resettable Fuse
Typical Application
C
OUT
1
F
IN
C
IN
1
F
FAULT
OUT
GND
AAT4680
5
2
1
3
INPUT
GND
GND
OUT
FAULT
Preliminary
Information
4680.2001.11.0.91
1
Pin Descriptions
Pin Configuration
SOT23-5
1
2
3
FAULT
OUT
4
5
GND
IN
NC
Pin #
Symbol
Function
1
OUT
P-channel MOSFET drain
2
GND
Ground connection
3
FAULT
Open drain output signals over-current and over-temperature condition
4
NC
Not internally connected
5
IN
P-channel MOSFET source
AAT4680
Electronic Resettable Fuse
2
4680.2001.11.0.9
Absolute Maximum Ratings
(T
A
=25C unless otherwise noted)
Note: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at con-
ditions other than the operating conditions specified is not implied. Only one Absolute Maximum rating should be applied at any one time.
Note 1: Human body model is a 100pF capacitor discharged through a 1.5k
resistor into each pin.
Thermal Characteristics
Note 2: Mounted on a demo board.
Electrical Characteristics
(V
IN
= 5V, T
A
= -40 to 85C unless otherwise noted. Typical values
are at T
A
=25C; bold values designate full temperature range)
Symbol
Description
Conditions
Min
Typ
Max
Units
V
IN
Operation Voltage
1.8
5.5
V
I
Q
Quiescent Current
V
IN
= 5V, I
OUT
= 0
10
20
A
V
UVLO
Undervoltage Lockout
V
IN
falling
1.5
1.8
V
V
UVLO(hys)
Undervoltage Lockout Hysteresis
0.3
V
R
DS(ON)
On-Resistance
V
IN
= 5.0V,T
A
= 25C
400
500
m
V
IN
= 3.V,T
A
= 25C
525
650
I
LIM
Current Limit
OUT < IN - 0.5V
0.6
0.875
1.25
A
t
RESP
Current Loop Response
V
IN
= 5V
500
ns
V
FAULTLOW
FAULT Logic Output Low
I
SINK
= 1mA
0.4
V
I
SINK
FAULT Logic Output High
V
FAULT
= 5.5V
0.5
1
A
Leakage Current
T
blank
FAULT Blanking Time
3
ms
T
SD
Over-temperature threshold
125
C
Symbol
Description
Value
Units
JA
Maximum Thermal Resistance
2
150
C/W
P
D
Maximum Power Dissipation
2
667
mW
Symbol
Description
Value
Units
V
IN
IN to GND
-0.3 to 6
V
V
OUT
OUT to GND
-0.3 to 6
V
V
FLG
FAULT to GND
-0.3 to 6
V
I
OUT
Output Current
Internally Limited
A
T
J
Operating Junction Temperature Range
-40 to 150
C
V
ESD
ESD Rating
1
- HBM
5000
V
T
LEAD
Maximum Soldering Temperature (at Leads)
300
C
AAT4680
Electronic Resettable Fuse
4680.2001.11.0.91
3
Typical Characteristics
(Unless otherwise noted, V
IN
= 5V, T
A
= 25C)
Short Circuit Through 0.6
0
2
4
6
-0.5
0.0
0.5
1.0
1.5
2.0
Time (
s)
Input and Output (V)
-1
1
3
5
Output (A)
Input Voltage
Output Current
Output Voltage
Short Circuit Through 0.3
-2
0
2
4
6
-0.5
0.0
0.5
1.0
1.5
2.0
Time (
s)
Input and Output (V)
-1
1
3
5
7
Output (A)
Input Voltage
Output Current
Output Voltage
R
DS
(ON) vs. Temperature
300
350
400
450
500
550
600
650
700
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
R
DS
(ON) (m
)
V
IN
=3V
V
IN
=5V
Current Limit vs. Output Voltage
Output (V)
Output (A)
0
0.2
0.4
0.6
0.8
1
0
1
2
3
4
5
Quiescent Current vs. Input Voltage
0
2
4
6
8
10
12
0
1
2
3
4
5
6
Input (V)
Quiescent Current (
A)
Quiescent Current vs. Temperature
0
2
4
6
8
10
12
14
16
18
20
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
Quiescent Current (
A)
AAT4680
Electronic Resettable Fuse
4
4680.2001.11.0.9
Typical Characteristics
(Unless otherwise noted, V
IN
= 5V, T
A
= 25C)
Fault Delay
2ms/div
FAULT (5V/div)
V
OUT
(2V/div)
I
IN
(500mA/div)
Thermal Shutdown Response
50ms/div
FAULT (5V/div)
V
OUT
(2V/div)
I
IN
(500mA/div)
AAT4680
Electronic Resettable Fuse
4680.2001.11.0.91
5
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