Datasheet AAT4601IHS-T1, AAT4601IHS-B1, AAT4601IAS-T1, AAT4601 Datasheet (Analogic Technologies)
Page 1
AAT4601
1.5A Current Limited P-Channel Switch
General Description
The AAT4601 SmartSwitch™ is part of
AnalogicTech's Application Specific Power
MOSFET™ (ASPM™) product family. It is a 1.5A
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 changes in load current which could cause the supply to fall out of regulation. The AAT4601 has protection from thermal
overload which limits power dissipation and junction temperatures. The maximum current limit
level is 1.5A; the actual threshold is programmed
with a resistor from the SET pin to ground. The quiescent supply current is typically 12µA. In shutdown mode, the supply current decreases to less
than 1µA.
The AAT4601 is available in 8-pin SOP or TSSOP
specified over -40 to 85°C.
SmartSwitch
Features
• 2.7V to 5.5V Input voltage range
• Programmable over current threshold
• Low quiescent current
• 12µA typical
• Less than 1µA with Switch off
• Only 2.5V needed for ON Control
• Thermal Shutdown
• Fault Flag
• 2ms Fault Blanking
• Undervoltage Lockout
• Temperature range -40 to 85°C
• 2kV ESD rating
• UL Approved—File No. E217765
• 8-pin SOP or TSSOP package
Applications
• USB ports
• Notebook computers
• Peripheral ports
• Hot swap supplies
™
Preliminary Information
UL Recognized Component
Typical Application
INPUT
100kΩ
1µF
4601.2001.11.0.92 1
ON
1
2
8
3
IN
IN
FAULT
ON
AAT4601
GND
4
6
OUT
7
OUT
5
SET
R
SET
OUTPUT
1uF
Page 2
AAT4601
1.5A Current Limited P-Channel Switch
Pin Descriptions
Pin # Symbol Function
1,2 IN These pins are the input to the P-channel MOSFET source. Connect a
1µF capacitor from IN to GND.
3 ON Active-Low Enable Input. A logic low turns the switch on.
4 GND Ground
5 SET Current-Limit Set Input. A resistor from SET to ground sets the current
limit for the switch.
6,7 OUT These pins are the P-channel MOSFET drain connection. Connect a 1µF
capacitor from OUT to GND.
8 FAULT Fault-Indication Output. This open-drain output goes low when in current
limit or when the die temperature exceeds +135 ºC, with a 2ms delay
after the fault event occurs.
Pin Configuration
SOP-8/TSSOP-8
(Top View)
1
IN
2
IN
3
ON
GND
4
1 2
8
FAULT
7
OUT
6
OUT
5
SET
2 4601.2001.11.0.92
Page 3
AAT4601
1.5A Current Limited P-Channel Switch
Absolute Maximum Ratings (T
=25°C unless otherwise noted)
A
Symbol Description Value Units
V
IN
V
ON,VFAULT
V
SET,VOUT
I
MAX
T
J
T
LEAD
V
ESD
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.
IN to GND -0.3 to 6 V
ON, FAULT to GND -0.3 to VIN+0.3 V
SET, OUT to GND -0.3 to VIN+0.3 V
Maximum Continuous Switch Current 3 A
Operating Junction Temperature Range -40 to 150 °C
Maximum Soldering Temperature (at Leads) 300 °C
ESD Rating—HBM
1
4000 V
Thermal Characteristics
Symbol Description Value Units
Θ
JA
P
D
Note 2: Mounted on an AATI demo board.
Typical Thermal Resistance
Maximum Power Dissipation
Electrical Characteristics (V
are at TA=25°C)
2
2
= 5V, TA= -40 to 85°C unless otherwise noted. Typical values
IN
100 °C/W
1.25 W
Symbol Description Conditions Min Typ Max Units
V
IN
I
Q
I
Q(OFF)
I
SD(OFF)
V
UVLO
R
DS(ON)
I
LIM
I
LIM(MIN)
TSD Shutdown Temperature VIN= 5V 125 ºC
V
ONL
V
ONH
I
ONSINK
V
FAULTL
I
FSINK
T
RESP
T
BLANK
T
OFF
T
ON
OTMP Over Temperature Shut Down 125 ºC
Note 3: Guaranteed by design.
Operation Voltage 2.7 5.5 V
Quiescent Current VIN= 5V, ON = GND, I
= 0 12 30 µA
OUT
Off Supply Current ON=IN, VIN= 5.5V .004 1 µA
Off Switch Current ON = IN, VIN= 5.5V, V
= 0 .07 15 µA
OUT
Undervoltage Lockout Rising edge, 1% hysteresis, 2.0 2.3 2.7 V
=5.0V 70 mΩ
V
IN
On-Resistance VIN=4.5V 75 130 mΩ
VIN=3.0V 80 150 mΩ
Current Limit R
= 2kΩ 510 715 920 mA
SET
Minimum Current Limit 250 mA
ON Input Low Voltage 0.8 V
=2.7V to 3.6V 2.0 V
V
ON Input High Voltage
IN
VIN=4.5V to 5.5V 2.4 V
ON Input leakage VON= 5.5V 0.01 1 µA
FAULT Logic Output Low Voltage I
FAULT Logic Output High Leakage V
=1mA 0.08 0.4 V
SINK
= 5.5V 0.05 1 µA
FAULT
Current Limit Response Time VIN=5V 2 µs
Fault Blanking Time after Turn-On 2 ms
Turn-Off Time
Turn-On Time
3
3
VIN=5V 20 µs
VIN=5V 200 µs
4601.2001.11.0.92 3
Page 4
Typical Characteristics
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4601
1.5A Current Limited P-Channel Switch
Quiescent Current vs. Temperature
25
20
15
10
5
Quiescent Current (µA)
0
-40 -20 0 20 40 60 80 100 120
Temperature
(°C)
Current Limit
1
0.8
0.6
0.4
Output (A)
0.2
R
= 2 k
SET
W
Input Voltage = 5 V
Quiescent Current
25
20
15
10
Input (µA)
5
0
0123456
Input (V)
2500
2000
1500
1000
Product (V)
R
SET ILIM
Product vs I
LIM
0
012345
Output (V)
Off-Supply Current vs. Temperature
10
1
0.1
0.01
0.001
Off-Supply Current (µA)
0.0001
-40-200 20406080100120140
Temperature
(°C)
500
0 0.5 1 1.5 2
Typical I
LIM
(A)
Off-Switch Current vs. Temperature
10
1
0.1
0.01
0.001
Off-Switch Current (µA)
0.0001
-40 -20 0 20 40 60 80 100 120 140
Temperature (°C)
4 4601.2001.11.0.92
Page 5
Typical Characteristics
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4601
1.5A Current Limited P-Channel Switch
Turn-On vs. Temperature
80
70
60
50
VIN=5V
40
30
20
10
Turn-ON Time (µs)
0
-40 -2 0 0 2 0 4 0 60 80 100 120
VIN=3V
Temperature (°C)
Switch Turn-On Time
6
I
5
4
3
2
1
Voltage (V)
0
-1
-20 -10 0 40 60 80
OUT=ILIMIT
ON
Output
Time (
Turn-Off vs. Temperature
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Turn-OFF Time (µs)
0
V
=3V
IN
VIN=5V
-40 - 20 0 20 40 60 80 100 120
Temperatur e (°C)
Switch Turn-Off Time
6
5
4
I
OUT=ILIMIT
3
2
1
Voltage (V)
0
-1
-4-20246
Output
Time (
ON
Short Circuit through 0.3Ω
8
(V)
6
4
2
Input and Output
0
02468
Output Current
Input Voltage
Output Voltage
Time (µs)
12
8
4
0
-4
Output (A)
8
(V)
6
4
2
Input and Output
0
-20 0 20 40 60 80 100 120 140
Short Circuit through 0.6Ω
Output Current
Input Voltage
Output Voltage
Time (µs)
9
6
3
0
-3
4601.2001.11.0.92 5
Output (A)
Page 6
Typical Characteristics
(Unless otherwise noted, VIN= 5V, TA= 25°C)
AAT4601
1.5A Current Limited P-Channel Switch
Fault Delay vs. Temperature
2.5
2.0
1.5
1.0
0.5
Fault Delay (ms)
0
-40 -2 0 0 20 40 60 80 100
Temperature (°C)
R
100
90
80
(mΩ)
DS(ON)
R
V
70
60
50
40
-40 -2 0 0 20 40 6 0 80
vs. Temperature
DS(ON)
=3V
IN
VIN=4.5V
Temperature (°C)
6 4601.2001.11.0.92
Page 7
Functional Block Diagram
AAT4601
1.5A Current Limited P-Channel Switch
IN
Under-
voltage
Lockout
ON
Over-temp
Protection
1.2V
Reference
Functional Description
The AAT4601 is an integrated MOSFET load
switch with an adjustable current limit, over temperature protection, level shifted input and a fault
flag. The current limit control is combined with an
over temperature thermal limit circuit to provide a
comprehensive system to protect the load switch
under short circuit or other adverse operating conditions. The AAT4601 is ideally suited for control
and protection of peripheral ports such as USB,
RS232 and parallel ports.
The current limit and over temperature circuits will
act independently. The device current limit is activated when the output load current exceeds an
internal threshold level. The internal current limit
threshold is determined by an external resistor
connected between the SET pin and ground. The
minimum current limit threshold is specified by
I
becomes excessive or if a short circuit condition
. If the load switch ambient temperature
LIM(MIN)
OUT
FAULT
Current
Limit
persists, the die temperature will rise causing the
over temperature protection circuit to activate.
If the current limit or over temperature protection
circuits are active for more then two milliseconds,
the system will be informed via the FAULT Flag.
The two millisecond delay allows the AAT4601 to
be turned on into capacitive loads without activating the FAULT Flag. The open drain FAULT output
can be connected directly to system controllers
driven by voltage levels less than the IN pin voltage
without additional level shifting circuitry.
The load switch is turned off by applying a logic high
level to the ON pin. The AAT4601 typically consumes 12µA when operating, when off, the device
draws less then 1µA. In the off state, current is prevented from flowing between the input and output.
The ON function has logic level thresholds that
allow the AAT4601 to be TTL compatible and may
also be controlled by 2.5V to 5.0V CMOS circuits.
The voltage level on either ON or FAULT should not
exceed the input supply level present on the IN pin.
SET
4601.2001.11.0.92 7
Page 8
Applications Information
Setting Current Limit
A simple three-step procedure can be used to
adjust the AAT4601's current limit. First, the maximum current required by the load should be determined. Second, select a resistor that guarantees
adequate current is available to the load under normal conditions. Finally, the maximum current that
can pass through the switch can be calculated and
compared to the maximum current available.
Step 1: The maximum current required by a load
is usually defined in port specifications design
application references. For example, USB ports
are specified to support loads of up to 500 mA.
Step 2: The most convenient method for determining a current limit resistor value is to look it up
in the provided table named "Current Limit R
Values". Find the lowest current value that is
greater than the maximum load current in the given
application. Refer to the column named "Device
will not current limit below". The resistor value
needed is in the corresponding row named "R
For example, a USB port requires 500 mA. The
lowest level where the device will current limit
above 500 mA is 516 mA. The corresponding
resistor value for R
Step 3: Now the required resistor value has been
determined. The maximum current that can be
drawn, even with a short circuit applied to the output, can be determined by reading the column
labeled "Device always current limits below". If the
power supply connected to the AAT4601's input can
provide this current level, the power supply voltage
will not collapse when a short circuit is applied to the
load switch output. For example, a notebook computer has a USB port which is powered by an
AAT4601 with a 2kΩ resistor connected between
the SET pin and GND. If the power supply connected to the AAT4601's IN pin can provide more
than 917 mA, this supply will remain in regulation
even if a short circuit is applied to the USB port.
would be 2kΩ .
SET
SET
SET
AAT4601
1.5A Current Limited P-Channel Switch
Current Limit R
R
SET
(Ω ) Limit typ not current current limits
470 1585 1141 2029
510 1529 1101 1957
560 1466 1055 1876
620 1397 1006 1788
680 1334 960 1707
750 1266 911 1620
820 1206 869 1544
910 1144 823 1464
1000 1089 784 1394
1100 1034 745 1324
1200 986 710 1262
1300 941 677 1204
1500 865 623 1107
1600 829 597 1061
1800 769 554 985
2000 716 516 917
".
2200 673 485 861
2400 633 456 811
2700 582 419 745
3000 539 388 690
3300 502 362 643
3600 470 339 602
3900 442 318 565
4300 410 295 524
4700 382 275 489
5100 358 258 458
5600 332 239 424
6200 306 220 392
6800 283 204 362
7500 268 193 343
Current Device will Device always
(mA) limit below: below:
(mA) (mA)
SET
Values
8 4601.2001.11.0.92
Page 9
AAT4601
0
1
2
3
4
5
6
-0.5 0 0.5 1 1.5 2
Output Voltage
1.5A Current Limited P-Channel Switch
Applications Information
Operation in Current Limit
If an excessive load is applied to the output of an
AAT4601, the load's current will be limited by the
AAT4601's current limit circuitry. Refer to the figure
named "Overload Operation". If a short circuit were
to occur on the load, it would demand more current
than what is allowed by the internal current limiting
circuit and the voltage at the AAT4601's output will
drop. This causes the AAT4601 to dissipate more
power than in normal operation, causing the die temperature to increase. When die temperature exceeds
the internal over temperature threshold, the AAT4601
will shut down. After shutting down, the AAT4601
cools to a level below the over temperature threshold, at which point it will start up again. The AAT4601
will continue to cycle off and on until one of the following events occurs; the load current is reduced to
a level below the AAT4601's current limit setting, the
input power is removed, or until the output is turned
off by a logic high level applied to the ON pin.
Thermal Considerations
Since the AAT4601 has internal current limit and
over temperature protection, junction temperature is
rarely a concern. If an application requires a large
load current in a high temperature operating environment, there is the possibility that the over temperature protection circuit rather than the current
limit circuit will regulate the current available to the
load. In these applications, the maximum current
available without risk of activation of the over temperature circuit can be calculated. The maximum
internal temperature while current limit is not active
can be calculated using Equation 1:
J(MAX)
= I
T
In Equation 1, I
by the load. R
R
of the AAT4601 at high temperature. R
DS(ON)
MAX
× R
MAX
DS(ON)
DS(ON)
(MAX) × R
+ TA(MAX)
θJA
is the maximum current required
(MAX) is the maximum rated
θJA
2
the thermal resistance between the AAT4601's die
and the board onto which it is mounted. TA(MAX) is
the maximum ambient temperature for the printed
circuit board assembly under the AAT4601 when the
load switch is not dissipating power. Equation 1 can
be transformed to provide I
T
I
MAX
SD
=
R
DS(ON)
; Refer to Equation 2.
MAX
(MIN) - TA(MAX)
(MAX) × R
θJA
TSD(MIN) is the minimum temperature required to
activate the AAT4601's over temperature protection. With typical specification of 125°C, 115°C is a
safe minimum value to use.
For example, a portable device is specified to operate in a 50°C environment. The printed circuit
board assembly will operate at temperatures as
high as 85°C. This portable device has a sealed
case and the area of the printed board assembly is
rellatively small causing R
to be approximately
θJA
120°C/W. Using Equation 2,
=
115 - 85
130 × 120
= 1.4 A
I
MAX
If this system requires less than 1.4 A, the thermal
limit will not activate during normal operation.
is
Overload Operation
Input Voltage
1 W is applied to output at t = 0
4601.2001.11.0.92 9
Voltage (V)
Time (s)
R
is 2 k
SET
W
Page 10
AAT4601
1.5A Current Limited P-Channel Switch
Applications Information
Input Capacitor
The input capacitor serves two purposes. First, it
protects the source power supply from transient
current effects generated by the application load
circuit. If a short circuit is suddenly applied to the
output of an AAT4601, there is a microsecond long
period during which a large can current flow before
the current limit circuitry activates. Refer to the
characteristic curve named "Short Circuit Through
0.3Ω." A properly sized input capacitor can dramatically reduce the load switch input transient
response effects seen by the power supply and
other circuitry upstream from the AAT4601.
The second purpose of the input capacitor is to
prevent transient events generated by the load circuit from affecting the operation of the AAT4601.
For example, if an AAT4601 is used in a circuit that
operates from a 3 volt power supply with poor step
load response, it is possible that turning on the load
switch could cause the input power supply to droop
below the AAT4601's under voltage lockout threshold. This drop in voltage would cause the AAT4601
to turn off until the input power supply's voltage
recovers. Since this cycle would be self-perpetuating, the entire circuit could be seen to be unstable.
In the very rare case where capacitor cost is prohibitive, the output load circuit should be slew rate
limited when turned on.
Output Capacitor
In order to insure stability while the device current
limit is active, a small capacitance of approximately
1µF should be used. When the AAT4601 is activated using the ON function, there are no momentary
current transients as in the case of when a short circuit suddenly applied to a device that is already on.
Refer to the characteristic curve named "Switch
Turn-On Time." No matter how big the output
capacitor, output current is limited to the value
allowed by the threshold determined by R
the internal current limiting circuitry. This permits
very large output capacitors to be used.
SET
and
For example, USB ports are specified to have at
least 120µF of down stream capacitance from their
controlling power switch. An output capacitance as
large as 1000µF would not disturb the input power
supply to the AAT4601 used to control the USB port.
ON Input
When the AAT4601 is in the off state, the output is
an open circuit and the device quiecent current
consumption is reduced to less than 1µA. The ON
threshold voltage is set to allow the AAT4601 to be
controlled by 5 volt TTL levels as well as CMOS
power from 2.5 volts to 5 volts. The ON function
control voltage level should not exceed the input
supply level applied to the IN pin.
FAULT Output
A FAULT flag is provided to alert a system if the load
switch is not receiving a sufficient voltage level to
operate properly. If either the current limit or over
temperature circuits in any combination are active
for more than approximately two milliseconds continuously, the FAULT pin is pulled to ground internally through a 100Ω resistance. The 2 millisecond
delay on the FAULT function is intended to prevent
capacitive loads connected to the load switch output from activating FAULT when the device is
turned on. The placement of a pull up resistor
between the FAULT pin and the IN pin is recommended. Reasonable values for the pull up resistor
should range from 10kΩ to 100kΩ. Since FAULT is
an open drain terminal, it may be pulled up to any
voltage that is not greater than the level present on
the IN pin. This is done to allow the AAT4601 to signal ancillary circuitry that is powered by voltage
level less than the level on the IN pin.
Reverse Voltage
The AAT4601 is designed to control current flowing
from IN to OUT. If a voltage is applied to OUT
which is greater than that on IN, a large resulting
reverse current may flow, potentially damaging the
AAT4601.
10 4601.2001.11.0.92
Page 11
AAT4601
1.5A Current Limited P-Channel Switch
Printed Circuit Board Layout
Recommendations
For proper thermal management, and to take
advantage of the low R
circuit board layout rules should be followed: V
and V
traces, and GND should be connected to a ground
plane. For best performance, CINand C
be placed close to the package pins.
Figure 1: AAT4601 Evaluation Figure 2: AAT4601 Evaluation Figure 3: AAT4601 Evaluation
board top side silk screen board component side layout board solder side layout
assembly drawing
should be routed using wider than normal
OUT
of the AAT4601, a few
DS(ON)
OUT
IN
should
Evaluation Board Layout
The AAT4601 evaluation layout follows the printed
circuit board layout recommendations, and can be
used for good applications layout.
Note: Board layout shown is not to scale.
4601.2001.11.0.92 11
Page 12
Ordering Information
AAT4601
1.5A Current Limited P-Channel Switch
Package Marking
SOP-8 AAT4601IAS-B1 AAT4601IAS-T1
TSSOP-8 AAT4601IHS-B1 AAT4601IHS-T1
Package Information
SOP-8
E
H
1 2
D
7(4x)
A
A2
b
y
A1
e
Part Number
Bulk Tape and Reel
Dim
Millimeters Inches
Min Max Min Max
A 1.35 1.75 0.053 0.069
A1 0.10 0.25 0.004 0.010
A2 1.45 0.057
B 0.33 0.51 0.013 0.020
C 0.19 0.25 0.007 0.010
D 4.80 5.00 0.189 0.197
E 3.80 4.00 0.150 0.157
e 1.27 0.050
H 5.80 6.20 0.228 0.244
L 0.40 1.27 0.016 0.050
Y 0.00 0.10 0.000 0.004
θ10° 8° 0° 8°
c
Note:
Q
L
1. PACKAGE BODY SIZES EXCLUDE MOLD FLASH
PROTRUSIONS OR GATE BURRS.
2. TOLERANCE± 0.1000mm (4mil) UNLESS
OTHERWISE SPECIFIED
3. COPLANARITY: 0.1000mm
4. DIMENSION L IS MEASURED IN GAGE PLANE.
5. CONTROLLING DIMENSION IS MILLIMETER;
CONVERTED INCH DIMENSIONS ARE NOT
NECESSARILY EXACT.
12 4601.2001.11.0.92
Page 13
AAT4601
1.5A Current Limited P-Channel Switch
TSSOP-8
1 2
b
Dim
Millimeters Inches
Min Max Min Max
A 1.05 1.20 0.041 0.047
A1 0.05 0.15 0.002 0.006
A2 - 1.05 - 0.041
b 0.25 0.30 0.010 0.012
E
E1
DETAIL A
c 0.127 0.005
D-8 2.90 3.10 0.114 0.122
D-28 9.60 9.80 0.378 0.386
E 4.30 4.50 0.170 0.177
E1 6.20 6.60 0.244 0.260
e 0.65 BSC 0.025 BSC
L 0.50 0.70 0.20 0.028
L1 1.0 0.039
D
e
A1
E
AA2
DETAIL A
0.20
R1
R
1
L
2
L1
R 0.09 - 0.004 R1 0.09 - 0.004 -
θ10° 8° 0° 8°
θ2 12°
4601.2001.11.0.92 13
Page 14
AAT4601
1.5A Current Limited P-Channel Switch
This page intentionally left blank.
Advanced Analogic Technologies, Inc.
1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086
Phone (408) 524-9684
Fax (408) 524-9689
14 4601.2001.11.0.92
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