SmartSwitch™
AAT4610
Current Limited Load Switch
4610.2006.09.1.3 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 1
NOT RECOMMENDED
FOR NEW DESIGNS
General Description
The AAT4610 SmartSwitch is a current limited P-
channel MOSFET power switch designed for high-
side load switching applications. This switch oper-
ates with inputs ranging from 2.7V to 5.5V, making it
ideal for both 3V and 5V systems. An integrated
current-limiting circuit protects the input supply
against large currents which may cause the supply
to fall out of regulation. The AAT4610 is also pro-
tected from thermal overload which limits power dis-
sipation and junction temperatures. It can be used
to control loads that require up to 1A. Current limit
threshold is programmed with a resistor from SET to
ground. The quiescent supply current is typically a
low 15µA max. In shutdown mode, the supply cur-
rent decreases to less than 1µA.
The AAT4610 is available in a Pb-free 5-pin SOT23
package and is specified over the -40°C to +85°C
temperature range.
Features
• Input Voltage Range: 2.7V to 5.5V
• Programmable Over-Current Threshold
• Fast Transient Response:
— <1µs Response to Short Circuit
• Low Quiescent Current
— 15µA Typical
— 1µA Max with Switch Off
• 160mΩTypical RDS(ON)
• Only 2.5V Needed for ON/OFF Control
• Under-Voltage Lockout
• Thermal Shutdown
• 4kV ESD Rating
• UL Approved—File No. E217765
• 5-Pin SOT23 Package
• Temperature Range: -40°C to +85°C
Applications
• Hot Swap Supplies
• Notebook Computers
• Peripheral Ports
• Personal Communication Devices
UL Recognized Component
Typical Application
AAT4610
ON/(ON)
IN
SET
INPUT
GND GND
GND
OUT
OUTPUT
ON (ON)
0.47μF
R
SET
1μF
AAT4610
Current Limited Load Switch
2Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 4610.2006.09.1.3
Pin Descriptions
Pin Configuration
SOT23-5
(Top View)
GND
IN
ON
SET
OUT
1
2
34
5
Pin # Symbol Function
1 OUT P-channel MOSFET drain. Connect 0.47µF capacitor from OUT to GND.
2 GND Ground connection
3 SET Current limit set input. A resistor from SET to ground sets the current limit for
the switch.
4 ON Enable input. Two versions are available, active-high and active-low. See
Ordering Information for details.
5 IN P-channel MOSFET source. Connect 1µF capacitor from IN to GND.
AAT4610
Current Limited Load Switch
4610.2006.09.1.3 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 3
Absolute Maximum Ratings1
TA= 25°C, unless otherwise noted.
Thermal Characteristics3
Symbol Description Value Units
ΘJA Thermal Resistance 150 °C/W
PDPower Dissipation 667 mW
Symbol Description Value Units
VIN IN to GND -0.3 to 6 V
VON ON (ON) to GND -0.3 to VIN + 0.3 V
VSET, VOUT SET, OUT to GND -0.3 to VIN + 0.3 V
IMAX Maximum Continuous Switch Current 2 A
TJOperating Junction Temperature Range -40 to 150 °C
TLEAD Maximum Soldering Temperature (at leads) 300 °C
VESD ESD Rating2- HBM 4000 V
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 1.5kΩresistor into each pin.
3. Mounted on a demo board.
Electrical Characteristics
VIN = 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= 25°C.
Symbol Description Conditions Min Typ Max Units
VIN Operation Voltage 2.7 5.5 V
IQQuiescent Current VIN = 5V, ON (ON) = Active, IOUT = 0 15 30 µA
IQ(OFF) Off Supply Current ON (ON) = Inactive, VIN = 5.5V 1 µA
ISD(OFF) Off Switch Current ON (ON) = Inactive, VIN = 5.5V, VOUT = 0 0.03 15 µA
VUVLO Under-Voltage Lockout Rising Edge, 1% Hysteresis 2.0 2.3 2.7 V
VIN = 5.0V 160 180
RDS(ON) On Resistance VIN = 4.5V 165 mΩ
VIN = 3.0V 195 230
ILIM Current Limit RSET = 6.8kΩ0.75 1 1.25 A
ILIM(MIN) Minimum Current Limit 150 mA
VON(L) ON (ON) Input Low Voltage 0.8 V
VON(H) ON (ON) Input High Voltage VIN = 2.7V to 3.6V 2.0 V
VIN = 4.5V to 5.5V 2.4
ION(SINK) ON (ON) Input leakage VON = 5.5V 0.01 1 µA
TRESP Current Limit Response Time VIN = 5V 0.8 µs
TOFF Turn-Off Time VIN = 5V, RL= 10Ω0.4 2 µs
TON Turn-On Time VIN = 5V, RL= 10Ω40 200 µs
TSD Over-Temperature Threshold VIN =5V TJIncreasing 125 °C
TJDecreasing 115
AAT4610
Current Limited Load Switch
4Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 4610.2006.09.1.3
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA= 25°C.
Off-Switch Current vs. Temperature
Temperature (
°
C)
Off-Switch Current (µA)
0.001
0.01
0.1
1
10
-40 -20 0 20 40 60 80 100 120
Off-Supply Current vs. Temperature
0.01
0.1
1
10
-40 -20 0 20 40 60 80 100 120
Temperature (
°
C)
Off-Supply Current (µA)
R
DS(ON)
vs. Temperature
0
50
100
150
200
250
-40 -20 0 20 40 60 80 100
Temperature (
°
C)
R
DS(ON)
(mΩ)
Input = 3V
Input = 5V
Output Current vs. Output Voltage
(R
SET
= 16k
Ω
)
0
0.2
0.4
0.6
012345
Output Voltage (V)
Output Current (A)
Quiescent Current vs. Input Voltage
0
10
20
30
40
2.5 3 3.5 4 4.5 5 5.5
Input Voltage (V)
Input Current (µA)
Quiescent Current vs. Temperature
0
5
10
15
20
25
-40 -20 0 20 40 60 80 100 120
Temperature (
°
C)
Quiescent Current (µA)
AAT4610
Current Limited Load Switch
4610.2006.09.1.3 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 5
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA= 25°C.
0
2
4
6
8
0123
-3
0
3
6
9
Short-Circuit Through 0.6
Time (µs)
Input and Output Voltage (V)
Output Current (A)
Output Voltage
Input Voltage
Output Current
Short-Circuit Through 0.3
Ω
0
2
4
6
8
0123
Time (µs)
Input and Output Voltage (V)
-4
0
4
8
12
Output Current (A)
Output Voltage
Input Voltage
Output Current
-1
0
1
2
3
4
5
6
- 0.5 0 0.5 1
Time (µs)
Voltage (V)
OutputON
Turn Off
(R
L
= 10
Ω
; I
OUT
= I
LIMIT
)
Turn On
(R
L
= 10
Ω
; C
L
= 0.47µF; I
OUT
= I
LIMIT
)
-1
0
1
2
3
4
5
6
- 20 0 20 40 60
Time (µs)
Voltage (V)
OutputON
Turn-Off Time vs. Temperature
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
- 40 - 20 0 20 40 60 80 100
Temperature (
°
C)
Turn-Off Time (µs)
V
IN
= 3V
V
IN
= 5V
Turn-On Time vs. Temperature
0
10
20
30
40
50
60
70
80
-40 -20 0 20 40 60 80 100
Temperature (
°
C)
Turn-On Time (µs)
V
IN
= 5V
V
IN
= 3V
AAT4610
Current Limited Load Switch
6Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 4610.2006.09.1.3
Typical Characteristics
Unless otherwise noted, VIN = 5V, TA= 25°C.
Current Limit vs. Temperature
(RSET = 22.1k
Ω
; VIN - VOUT = 0.5V)
-6
-4
-2
0
2
4
6
-50 - 25 0 25 50 75 100
Temperature (
°
C)
Current Limit (%)
R
SET
Coefficient vs. I
LIM
5
6
7
8
9
10
0 0.5 1 1.5 2
I
LIM
(A)
R
SET
I
LIM
Product (kV)
R
SET
vs. I
LIM
1
10
100
0.1 101
I
LIM
(A)
R
SET
(k
Ω
)
AAT4610
Current Limited Load Switch
4610.2006.09.1.3 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 7
AAT4610
Current Limited Load Switch
8Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 4610.2006.09.1.3
Functional Block Diagram
Current
Limit
1.2V
Reference
Under-
Voltage
Lockout
Over-Temperature
Protection
OUT
SET
GND
R
SET
ON (ON)
IN
Applications Information
Setting Current Limit
In most applications, the variation in ILIM must be
taken into account when determining RSET. The ILIM
variation is due to processing variations from part
to part, as well as variations in the voltages at IN
(Pin 5) and OUT (Pin 1), plus the operating tem-
perature. See the charts "Current Limit vs.
Temperature" and "Output Current vs. VOUT" in the
Typical Characteristics section of this datasheet.
Together, these three factors add up to a ±25% tol-
erance (see ILIM specification in the Electrical
Characteristics section of this datasheet). Figure 1
shows a cold device with a statistically higher cur-
rent limit, and a hot device with a statistically lower
current limit, both with RSET equal to 10.5kΩ. While
the chart, "RSET vs. ILIM" indicates an ILIM of 0.7A
with an RSET of 10.5kΩ, this figure shows that the
actual current limit will be at least 0.525A, and no
greater than 0.880A.
Figure 1: Output Current Using 10.5kΩΩ.
To determine RSET, start with the maximum current
drawn by the load, and multiply it by 1.33 (typi-
cal_ILIM = minimum_ILIM / 0.75). This is the typical
current limit value. Next, refer to "RSET vs. ILIM" and
find the RSET that corresponds to the typical current
limit value. Choose the largest resistor available
that is less than or equal to it. For greater precision,
Ω
0
0.2
0.4
0.6
0.8
1
1.2
0 12345
V
OUT
(V)
I
LIM
(A)
0.88A
0.525A
Device with high current limit at -40°C
Device with low current limit at 85°C
the value of RSET may also be calculated using the
ILIM RSET product found in the chart "RSET
Coefficient vs. ILIM". The maximum current is
derived by multiplying the typical current for the
chosen RSET in the chart by 1.25. A few standard
resistor values are listed in Table 1.
Table 1: Current Limit RSET Values.
Example: A USB port requires 0.5A. 0.5A multiplied
by 1.33 is 0.665A. From the chart "RSET vs. ILIM," RSET
should be less than 11kΩ. 10.5 kΩis a standard value
that is a little less than 11kΩ. The chart gives approx-
imately 0.700A as a typical ILIM value for 10.5kΩ.
Multiplying 0.700A by 0.75 and 1.25 shows that the
AAT4610 will limit the load current to greater than
0.525A but less than 0.875A.
Operation in Current Limit
When a heavy load is applied to the output of the
AAT4610, the load current is limited to the value of
ILIM determined by RSET (see Figure 2). Since the
load is demanding more current than ILIM, the volt-
age at the output drops. This causes the AAT4610 to
dissipate a larger than normal quantity of power, and
results in increased die temperature. When the die
temperature exceeds an over-temperature limit, the
AAT4610 will shut down until is has cooled suffi-
ciently, at which point it will start up again. The
AAT4610 will continue to cycle on and off until the
load is removed, power is removed, or until a logic
high level is applied to ON (Pin 4).
Enable Input
In many systems, power planes are controlled by
integrated circuits which run at lower voltages than
the power plane itself. The enable input ON (Pin 4)
of the AAT4610 has low and high threshold volt-
ages that accommodate this condition. The thresh-
old voltages are compatible with 5V TTL and 2.5V
to 5V CMOS.
Reverse Voltage
The AAT4610 is designed to control current flowing
from IN to OUT. If a voltage is applied to OUT which
is greater than the voltage on IN, large currents may
flow. This could damage the AAT4610.
AAT4610
Current Limited Load Switch
4610.2006.09.1.3 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 9
0
1
2
3
4
5
-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3
Output Voltage (V)
0
0.25
0.5
0.75
1
Output Current (A)
Output Current
Output Voltage
1Ωload is turned on at time = 0
Device Will Device Always
Current Not Current Current Limits
RSET Limit Limit Below Below
(kΩΩ) Typ (mA) (mA) (mA)
40.2 200 150 250
30.9 250 188 313
24.9 300 225 375
22.1 350 263 438
19.6 400 300 500
17.8 450 338 563
16.2 500 375 625
14.7 550 413 688
13.0 600 450 750
10.5 700 525 875
8.87 800 600 1000
7.50 900 675 1125
6.81 1000 750 1250
6.04 1100 825 1375
5.49 1200 900 1500
4.99 1300 975 1625
4.64 1400 1050 1750
Figure 2: Overload Operation.
AAT4610
Current Limited Load Switch
10 Not recommended for new designs; pin-for-pin upgrade: AAT4610A. 4610.2006.09.1.3
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
Ordering Information
Package Information
SOT23-5
All dimensions in millimeters
4
°
±
4
°
0.15
±
0.07
0.45
±
0.15 0.10 BSC
1.20
±
0.25
1.575
±
0.125
2.80
±
0.20
0.40
±
0.10
0.60 REF
2.85
±
0.15
1.90 BSC
0.95
BSC
1.10
±
0.20
10
°
±
5
°
GAUGE PLANE
0.075
±
0.075
0.60 REF
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means
semiconductor products that are in compliance with current RoHS standards, including
the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more
information, please visit our website at http://www.analogictech.com/pbfree.
Package Enable Marking1Part Number (Tape and Reel)2
SOT23-5 ON (active low) AAXYY AAT4610IGV-T1
SOT23-5 ON (active high) AWXYY AAT4610IGV-1-T1
1. XYY = assembly and date code.
2. Sample stock is generally held on all part numbers listed in BOLD.
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