Current Limited Load Switch
General Description
The AAT4612 SmartSwitch is a current limited P-
channel MOSFET power switch designed for high-
side load switching applications operating with
inputs ranging from 2.4V to 5.5V, making it ideal for
both 3V and 5V systems. An integrated current
limiting circuit protects the input supply from large
currents which could potentially cause the supply
to fall out of regulation. In addition, the AAT4612’s
thermal overload protection limits power dissipa-
tion and junction temperatures associated with pro-
longed periods of operation in current limit. Due to
its low R
DS(ON)
, the AAT4612 can be used to control
loads that require up to 1A even while operating at
high ambient temperatures. The ultra-fast current
limit response to a sudden short circuit is a mere
500ns which reduces the requirements of local
supply bypassing. Quiescent current is a low 10µA
and, in shutdown mode, the supply current
decreases to less than 1µA.
The AAT4612 is available in a Pb-free 5-pin SOT23
package or a Pb-free 8-pin SC70JW package and
is specified over the -40°C to +85°C temperature
range.
AAT4612
Features
•
•
•
•
•
•
•
•
•
•
SmartSwitch
™
Input Voltage Range: 2.4V to 5.5V
1A Current Limit Trip Threshold
Fast Transient Response:
• <1µs Response to Short Circuit
Low Quiescent Current:
• 10µA Typ
• 1µA Max with Switch Off
100mΩ Typical R
DS(ON)
Under-Voltage Lockout
Thermal Shutdown
4kV ESD Rating
5-Pin SOT23 or 8-Pin SC70JW Package
-40°C to +85°C Temperature Range
Applications
•
•
•
•
Hot Swap Supplies
Notebook Computers
Peripheral Ports
Personal Communication Devices
Typical Application
INPUT
IN
OUT
V
CC
AAT4612
C
IN
1μF
ON
ON
GND
C
OUT
0.47μF
GND
GND
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1
Current Limited Load Switch
Absolute Maximum Ratings
1
T
A
= 25°C unless otherwise noted.
Symbol
V
IN
V
ON
V
OUT
I
OUT
T
J
V
ESD
T
LEAD
AAT4612
Description
IN to GND
ON to GND
OUT to GND
Output Current
Operating Junction Temperature Range
ESD Rating
2
—HBM
Maximum Soldering Temperature (at Leads)
Value
-0.3 to 6
-0.3 to 6
-0.3 to 6
Internally Limited
-40 to 150
4000
300
Units
V
V
V
A
°C
V
°C
Thermal Characteristics
3
Symbol
Θ
JA
P
D
Description
Maximum Thermal Resistance (SOT23-5, SC70JW-8)
Maximum Power Dissipation (SOT23-5, SC70JW-8)
Value
150
667
Units
°C/W
mW
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi-
tions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
3. Mounted on a demo board.
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3
Current Limited Load Switch
Electrical Characteristics
V
IN
= 5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= 25°C;
bold
values denote
full temperature range.
Symbol
V
IN
I
Q
I
Q(OFF)
I
SD(OFF)
V
UVLO
V
UVLO(hys)
R
DS(ON)
I
LIM
V
ON(L)
V
ON(H)
I
ON(SINK)
t
RESP
T
OFF
T
ON
OTMP
AAT4612
Description
Operation Voltage
Quiescent Current
Off Supply Current
Off Switch Current
Under-Voltage Lockout
Under-Voltage Lockout Hysteresis
On Resistance
Current Limit
ON Input Low Voltage
ON Input High Voltage
ON Input leakage
Current Loop Response
Turn-Off Time
Turn-On Time
Over-Temperature Shutdown
Conditions
V
IN
= 5V, ON = Active, I
OUT
= 0
ON = Inactive, V
IN
= 5.5V
ON = Inactive, V
IN
= 5.5V, V
OUT
= 0
V
IN
Falling
V
IN
= 5.0V, T
A
= 25°C
V
IN
= 3.0V, T
A
= 25°C
V
OUT
= V
IN
to 0.5V
V
IN
= 2.7V to 5.5V
1
V
IN
= 2.7V
≤
4.2V
V
IN
= > 4.2V to 5.0V
1
V
ON
= 5.5V
V
IN
= 5V
V
IN
= 5V, R
L
= 10Ω
V
IN
= 5V, R
L
= 10Ω
Min
2.4
Typ
10
0.1
1.9
0.3
130
170
1.5
Max
5.5
20
1
1
Units
V
µA
µA
µA
V
V
mΩ
A
V
V
1
2.0
2.4
175
225
2.0
0.8
0.01
500
2.5
1
125
1
µA
ns
µs
µs
°C
1. For V
IN
outside this range, consult typical ON threshold curve.
4
4612.2006.09.1.3
Current Limited Load Switch
Typical Characteristics
Quiescent Current vs. Temperature
20
20
AAT4612
Quiescent Current vs. Input Voltage
Quiescent Current (µA)
15
Quiescent Current (µA)
-40
-20
0
20
40
60
80
100
120
15
10
10
5
5
0
0
0
1
2
3
4
5
6
Temperature (°C)
Input Voltage (V)
Current Limit vs. Output Voltage
1.4
1.2
250
R
DS(ON)
vs. Temperature
V
IN
= 3V
200
Current Limit (A)
R
DS(ON)
(mΩ)
Ω
1.0
0.8
0.6
0.4
0.2
0.0
0
1
2
3
4
5
150
V
IN
= 5V
100
50
0
-40
-20
0
20
40
60
80
100
120
Output Voltage (V)
Temperature (°C)
°
Off-Supply Current vs. Temperature
Off-Supply Current (µA)
1.00
1.00
Off-Switch Current vs. Temperature
Off-Switch Current (µA)
0.10
0.10
0.01
0.01
0.00
-40
-20
0
20
40
60
80
100
120
0.00
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
Temperature (°C)
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