Analogic AAT4608 Current limited load switch in sot-23 package Datasheet

AAT4608
Current Limited Load Switch in SOT-23 Package
General Description
Features
The AAT4608 SmartSwitch™ is a member of
AnalogicTech's Application Specific Power
MOSFET™ (ASPM™) product family. It is a Current
Limited P-channel MOSFET power switch designed
for high-side load-switching applications. This switch
operates 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 AAT4608 is also protected from thermal overload which limits power dissipation and junction temperatures. It can be used
to control loads that require up to 1 A. Current limit
threshold is programmed with a resistor from SET to
ground. The quiescent supply current is typically a
low 15µA max.
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The AAT4608 is available in a 5 pin SOT-23 specified over -40 to 85°C.
Applications
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•
2.7V to 5.5V Input voltage range
Programmable over current threshold
Fast transient response:
<1µs response to short circuit
Low quiescent current
• 15µA typical
• 1µA max with Switch off
160mΩ typical R DS(ON)
Undervoltage Lockout
Thermal shutdown
Temp range -40 to 85°C
4kV ESD Rating
5 pin SOT-23 package
Preliminary Information
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•
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SmartSwitch™
Peripheral ports
Notebook computers
Personal communication devices
Hot swap supplies
Typical Application
INPUT
5
IN
AAT4608
OUTPUT
1
OUT
SOT-23
3
SET
GND
1µF
GND
4608.2001.10.0.9
2
RSET
0.47µF
GND
1
AAT4608
Current Limited Load Switch in SOT-23 Package
Pin Configuration
5-Pin SOT-23
(Top View)
OUT
1
GND
2
SET
3
5
IN
4
NC
Pin Descriptions
2
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
NC
No internal connection.
5
IN
P-channel MOSFET source. Connect 1µF capacitor from IN to GND.
4608.2001.10.0.9
AAT4608
Current Limited Load Switch in SOT-23 Package
Absolute Maximum Ratings
(TA=25°C unless otherwise noted)
Symbol
Description
VIN
VSET, VOUT
IMAX
TJ
TLEAD
VESD
IN to GND
SET, OUT to GND
Maximum Continuous Switch Current
Operating Junction Temperature Range
Maximum Soldering Temperature (at Leads)
ESD Rating1 - HBM
Value
Units
-0.3 to 6
-0.3 to VIN+0.3
2
-40 to 150
300
4000
V
V
A
°C
°C
V
Note: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions 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 1.5kΩ resistor into each pin.
Thermal Characteristics
Symbol
Description
ΘJA
PD
Value
Units
150
667
°C/W
mW
2
Thermal Resistance
Power Dissipation2
Note 2: Mounted on a demo board.
Electrical Characteristics
(VIN = 5V, TA = -40 to 85°C unless otherwise noted. Typical values
are at TA=25°C)
Symbol
VIN
IQ
VUVLO
RDS(ON)
ILIM
ILIM(MIN)
TRESP
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Description
Operation Voltage
Quiescent Current
Undervoltage Lockout
On-Resistance
Current Limit
Minimum Current Limit
Current Limit Response Time
Conditions
Min
Typ
2.7
VIN = 5V, IOUT = 0
Rising edge, 1% hysteresis,
VIN=5.0V
VIN=4.5V
VIN=3.0V
RSET = 6.8kΩ
VIN=5V
2.0
0.5
15
2.3
160
165
195
1
150
0.8
Max
5.5
30
2.7
180
230
2.0
Units
V
µA
V
mΩ
mΩ
mΩ
A
mA
µs
3
AAT4608
Current Limited Load Switch in SOT-23 Package
Typical Characteristics
(Unless otherwise noted, VIN = 5V, TA = 25°C)
Quiescent Current
25
40
20
30
Input ( µA )
Quiescent Current (µA)
Quiescent Current vs. Temperature
15
10
5
20
10
0
-40
-20
0
20
40
60
80
100
120
0
2.5
Temperature (C)
3
3.5
4
4.5
5
5.5
Input ( V )
Output Current vs VOUT
RDS(ON) vs. Temperature
250
200
RDS(ON) (mΩ)
Output Current ( A)
0.6
0.4
RSET =16 kΩ
0.2
Input = 3 V
150
Input = 5V
100
50
0
0
-40
0
1
2
3
4
-20
0
20
40
60
80
100
5
Te mperature (C)
Vout ( V )
Short Circuit through 0.3Ω
Short Circuit through 0.6Ω
Input Voltage
8
4
Output Current
4
2
0
Output Voltage
0
-4
0
1
2
Time (µs)
4
3
9
Input Voltage
6
4
6
3
Output Current
2
0
Output (A)
6
8
Input and Output (V)
12
Output (A)
Input and Output (V)
8
Output Voltage
0
-3
0
1
2
3
Time (µs)
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AAT4608
Current Limited Load Switch in SOT-23 Package
(Unless otherwise noted, VIN = 5V, TA = 25°C)
RSET vs ILIM
RSET coefficent vs I LIM
10
R SET I LIM Product ( kV )
R SET (kΩ)
100
10
1
0.1
9
8
7
6
5
1
10
I LIM (A)
0
0.5
1
1.5
2
I LIM (A)
Current Limit v. Temperature
Current Limit (%)
6%
RSET = 22.1k
V IN -VOUT=0.5V
4%
2%
0%
-2%
-4%
-6%
-50
- 25
0
25
50
75
100
Temperature (C)
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5
AAT4608
Current Limited Load Switch in SOT-23 Package
Functional Block Diagram
IN
OUT
Undervoltage
Lockout
Over-Temp
Protection
1.2V
Reference
Current
Limit
SET
RSET
GND
6
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AAT4608
Current Limited Load Switch in SOT-23 Package
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 3), plus the operating temperature. See charts "Current Limit vs. Temperature",
and "Output Current vs. VOUT". Together these
three factors add up to a ±25% tolerance (see ILIM
specification in Electrical Characteristics section).
In the figure below, a cold device with a statistically higher current limit, and a hot device with a statistically lower current limit, both with RSET equal to
10.5kΩ are shown. While the chart, "R SET 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.
Current Limit Using 10.5 kΩ
1.2
Device with high current limit at -40°C
0.88 A
1
I LIM (A)
0.8
0.6
0.525 A
0.4
Device with low current limit at 85°C
0.2
0
0
1
2
3
4
5
VOUT (V )
To determine RSET, start with the maximum current
drawn by the load, and multiply it by 1.33. (typical_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
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that is less than or equal to it. For greater precision,
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 the table "Current Limit RSET Values".
Current Limit RSET Values
RSET
(kΩ)
Current
Limit typ
(mA)
40.2
30.9
24.9
22.1
19.6
17.8
16.2
14.7
13.0
10.5
8.87
7.50
6.81
6.04
5.49
4.99
4.64
200
250
300
350
400
450
500
550
600
700
800
900
1000
1100
1200
1300
1400
Device will
not current
limit below:
(mA)
150
188
225
263
300
338
375
413
450
525
600
675
750
825
900
975
1050
Device always
current limits
below:
(mA)
250
313
375
438
500
563
625
688
750
875
1000
1125
1250
1375
1500
1625
1750
Example: A USB port requires 0.5A. 0.5A multiplied
by 1.33 is 0.665A. From the chart named "RSET vs.
ILIM", RSET should be less than 11kΩ. 10.5 kΩ is a
standard value that is a little less than 11kΩ but
very close. The chart reads approximately 0.700A
as a typical ILIM value for 10.5kΩ. Multiplying
0.700A by 0.75 and 1.25 shows that the AAT4608
will limit the load current to greater than 0.525A but
less than 0.875A.
7
AAT4608
Current Limited Load Switch in SOT-23 Package
Overload Operation
1
0.75
0.25
0
5
Output Current
4
3
1Ω load is turned on at time = 0
Output (A)
Output ( V )
0.5
Output Voltage
2
1
0
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
Tim e ( s )
Operation in Current Limit
Reverse Voltage
When a heavy load is applied to the output of the
AAT4608, the load current is limited to the value of
ILIM determined by RSET. See the figure "Overload
Operation". Since the load is demanding more current than ILIM, the voltage at the output drops. This
causes the AAT4608 to dissipate a larger than normal quantity of power, and its die temperature to
increase. When the die temperature exceeds an
over temperature limit, the AAT4608 will shut down
until is has cooled sufficiently, at which point it will
startup again. The AAT4608 will continue to cycle
on and off until the load is removed or power is
removed.
The AAT4608 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 cause damage to the AAT4608.
8
4608.2001.10.0.9
AAT4608
Current Limited Load Switch in SOT-23 Package
Ordering Information
Part Number
Package
Marking
Bulk
Tape and Reel
SOT-23-5
N/A
AAT4608IGV-T1
SOT-23-5
N/A
AAT4608IGV-1-T1
Package Information
SOT-23-5
e
Dim
S1
H
E
D
A
A1
S
b
c
I
L
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A
A1
A2
b
c
D
E
e
H
L
S
S1
Θ
Millimeters
Min
Max
0.95
1.45
0.05
0.15
0.90
1.30
0.35
0.50
0.08
0.20
2.84
3.00
1.50
1.70
1.90
2.60
3.00
0.35
0.55
0.47
0.55
.95
0°
10°
Inches
Min
Max
0.037
0.057
0.002
0.006
0.035
0.051
0.014
0.019
0.003
0.078
0.112
0.112
0.059
0.067
0.0748
0.102
0.118
.0137
.0216
0.019
.0216
0.037
0°
10°
9
AAT4608
Current Limited Load Switch in SOT-23 Package
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Advanced Analogic Technologies, Inc.
1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086
Phone (408) 524-9684
Fax (408) 524-9689
10
4608.2001.10.0.9
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