ANALOGICTECH AAT4670IWP-T1

AAT4670
Dual-Input, Dual-Output Load Switch
General Description
Features
The AAT4670 SmartSwitch is a member of
AnalogicTech’s Application Specific Power MOSFET™ (ASPM™) product family. The AAT4670
consists of dual, independent, 1A current limited,
slew rate controlled P-channel MOSFET power
switches with a dedicated source and drain pin
assigned to each switch. The internal circuitry automatically derives power from the higher of the two
input power source pins with a low operating quiescent current of 18µA. In shutdown mode, the supply
current decreases to less than 1µA. The switches
operate with inputs ranging from 2.2V to 5.5V, making them ideal for 2.5V, 3V, and 5V systems. The
dual configuration permits integration of the load
switch function for systems with two different power
busses. Independent under-voltage lockout circuits
will shut down the corresponding switch if its input
voltage falls below the under-voltage lockout threshold. If the die temperature reaches the thermal limit,
both switches thermal cycle off and on indefinitely
without damage until the thermal condition is
removed. An open drain FAULT output signals an
over-current or over-temperature condition for each
channel. Input logic levels are TTL compatible.
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SmartSwitch™
2.2V to 5.5V Input Voltage Range
1A Current Limit Per Channel
95mΩ Typical RDS(ON)
Fast Transient Response:
— <1µs Response to Short Circuit
Low 18µA Quiescent Current
1µA Max with Switches Off
Slew Rate Controlled
Thermal Shutdown
Fault Flags with 3ms Blanking
Under-Voltage Lockout
Temperature Range: -40°C to +85ºC
Available in TDFN33-12, SOP-8, TSSOP-8, or
MSOP-8 Package
Applications
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The AAT4670 is available in a Pb-free, space-saving, thermally-enhanced TDFN 3x3x0.8mm 12-lead
package. The device is also available in a Pb-free
8-pin SOP, TSSOP, or MSOP package and is specified over the -40°C to +85°C temperature range.
Hot Swap Supplies
Media Bay
Notebook Computer
PDA, Subnotebook
Peripheral Ports
USB Ports
Typical Application
AAT4670
INA
INB
EN
INA
INB
EN
GND
CINA
1μF
GND
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CINB
1μF
OUTA
OUTB
FAULTA
FAULTB
OUTA
OUTB
FAULTA
FAULTB
COUTA
1μF
COUTB
1μF
GND
1
AAT4670
Dual-Input, Dual-Output Load Switch
Pin Descriptions
Pin #
TDFN
Other Pkgs
Symbol
Function
1, 12
8
OUTA
2
1
EN
3
2
FAULTA
Open drain output; signals over-current for OUTA and over-temperature condition.
4
3
FAULTB
Open drain output; signals over-current for OUTB and over-temperature condition.
5
4
GND
Ground connection.
6, 7
5
OUTB
P-channel MOSFET drain channel B.
8, 9
6
INB
P-channel MOSFET source channel B.
10, 11
7
INA
P-channel MOSFET source channel A.
P-channel MOSFET drain channel A.
Active-low enable input (logic low turns the switches on).
EP
Exposed paddle (bottom); connect to ground as closely as possible to
the device.
Pin Configuration
TDFN33-12
3
10
4
9
5
8
6
7
OUTA
INA
INA
INB
INB
OUTB
8
OUTA
7
INA
3
6
INB
4
5
OUTB
8
OUTA
2
11
1
12
2
2
1
1
OUTA
EN
FAULTA
FAULTB
GND
OUTB
SOP-8
7
INA
EN
1
FAULTA
2
FAULTB
GND
TSSOP-8
2
MSOP-8
EN
1
INA
FAULTA
2
6
INB
FAULTB
3
6
INB
5
OUTB
GND
4
5
OUTB
EN
1
8
OUTA
FAULTA
2
7
FAULTB
3
GND
4
4670.2006.09.1.4
AAT4670
Dual-Input, Dual-Output Load Switch
Absolute Maximum Ratings1
TA = 25°C, unless otherwise noted.
Symbol
Description
VINA,B
VOUTA,B
VFAULTA,B
IOUT
TJ
VESD
TLEAD
INA or INB to GND
OUTA or OUTB to GND
FAULTA or FAULTB to GND
Output Current
Operating Junction Temperature Range
ESD Rating2 - HBM
Maximum Soldering Temperature (at Leads)
Value
Units
-0.3 to 6
-0.3 to 6
-0.3 to 6
Internally Limited
-40 to 150
4000
300
V
V
V
A
°C
V
°C
Value
Units
Thermal Characteristics3
Symbol
Description
ΘJA
Maximum Thermal Resistance
PD
Maximum Power Dissipation
SOP-8
TDFN33-12
SOP-8
TDFN33-12
100
50
1.25
2.0
°C/W
W
1. 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.
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
AAT4670
Dual-Input, Dual-Output Load Switch
Electrical Characteristics
VIN = 5V, TA = 25°C, unless otherwise noted. Bold values designate -40°C to +85°C temperature range.
Symbol Description
VIN
IQ
ILIM
t1
t2
t3
t4
VEN(L)
Operation Voltage
Quiescent Current
Off Supply Current
Off Switch Current
Under-Voltage Lockout
On-Resistance Channel
A or B
Switch Resistance
Temperature Coefficient
Current Limit Channel A or B
Output Turn-On Delay Time
Output Rise Time
Output Turn-Off Delay Time
Output Fall Time
EN Input Low Voltage
VEN(H)
EN Input High Voltage
IQ(OFF)
ISD(OFF)
VUVLO
RDS(ON)
TCRDS
IEN(SINK)
tRESP
VFAULTLOW
ISINK
Tblank
TSD
EN Input Leakage
Current Loop Response
FAULT Logic Output Low
FAULT Logic Output High
Leakage Current
Fault Blanking Time
Over-Temperature Threshold
Conditions
Min
Typ
2.2
VINA or VINB = 5V IOUTA = IOUTB = 0
EN = VIN, VINA = VINB = 5V, OUTA, OUTB Open
EN = VIN, VINA = VINB = 5V, VOUTA = VOUTB = 0V
18
0.1
1.7
95
105
VIN = 5.0V
VIN = 3.0V
Max Units
5.5
40
1
1
2.2
130
150
2800
VOUT < VIN to 0.5V
VIN = 5V, OUT = 0 to 10%, RLOAD = 20Ω
VIN = 5V, OUT = 10% to 90%, RLOAD = 20Ω
VIN = 5V, OUT = 100% to 90%, RLOAD = 20Ω
VIN = 5V, OUT = 90% to 10%, RLOAD = 20Ω
VIN = 2.7V to 5.5V1
VIN = 2.7V to < 3.6V
VIN = 3.6V to 5.5V
VEN = 5.5V
VIN = 5V
ISINK = 1mA
VFAULT = 5.5V
1.0
1.25
100
100
10
5
V
µA
µA
µA
V
mΩ
ppm/°C
1.50
1000
1000
20
20
0.8
2.0
2.4
A
µs
µs
µs
µs
V
V
0.01
750
0.5
3
125
1
0.4
1
µA
ns
V
µA
ms
°C
1. For VIN outside this range, consult typical EN threshold curve.
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4670.2006.09.1.4
AAT4670
Dual-Input, Dual-Output Load Switch
Typical Characteristics
Quiescent Current vs. Temperature
Quiescent Current vs. Input Voltage
20
18
25
Input Current (μA)
Quiescent Current (μA)
30
20
15
10
5
0
16
14
12
10
8
6
4
2
0
-40
-20
0
20
40
60
80
100
120
0
1
2
Off-Supply Current vs. Temperature
5
6
1.0000
Off-Switch Current (μA)
Off-Supply Current (μA)
4
Off-Switch Current vs. Temperature
1.0000
0.1000
0.0100
0.0010
0.0001
0.0000
-40
-20
0
20
40
60
80
100
0.1000
0.0100
0.0010
0.0001
0.0000
120
-40
-20
0
Temperature (°C)
20
40
60
80
100
120
Temperature (°C)
Current Limit vs. Output Voltage
RDS(ON) vs. Temperature
1.4
150
1.2
140
1.0
RDS(ON) (mΩ)
Output Current (A)
3
Input Voltage (V)
Temperature (°C)
0.8
0.6
0.4
130
VIN = 3V
120
110
100
90
VIN = 5V
80
0.2
70
0.0
60
0
1
2
3
Output Voltage (V)
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4
5
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
5
AAT4670
Dual-Input, Dual-Output Load Switch
Typical Characteristics
FAULT Delay
Start Into 0.6Ω Load
Turn-On/Off Response with 20Ω 1µF Loads
EN (5V/div)
FAULT (5V/div)
ON (5V/div)
OUTB (5V/div) INB = 5V
FAULT (5V/div)
OUTA (5V/div) INA = 3V
VOUT (1V/div)
IINA + IINB (200mA/div)
IIN (500mA/div)
Time (100µs/div)
Time (500µs/div)
Short Circuit Through 0.3Ω
9
4
6
3
Output Current
2
0
Output Voltage
0
-3
-1
0
1
2
3
4
8
12
Input Voltage
6
4
4
Output Current
2
0
0
Output Voltage
-2
-4
-1
Time (μs)
8
Output Current (A)
Input Voltage
6
Input and Output Voltage (V)
8
Output Current (A)
Input and Output Voltage (V)
Short Circuit Through 0.6Ω
0
1
2
3
4
Time (μs)
Typical EN Threshold vs. Input Voltage
Thermal Shutdown Response
ON (5V/div)
FAULT (5V/div)
VOUT (1V/div)
IIN (500mA/div)
EN Threshold (V)
2.4
2.2
2
1.8
VEN(H)
1.6
1.4
1.2
VEN(L)
1
0.8
0.6
1.5
Time (200ms/div)
6
2
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
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AAT4670
Dual-Input, Dual-Output Load Switch
Functional Block Diagram
INA
OUTA
ILIM
Slew
Rate
UVLO
EN
OTMP
UVLO
ILIM
Slew
Rate
INB
OUTB
FAULTA
FAULTB
GND
Functional Description
The AAT4670 dual channel load switch, implemented with isolated independent P-channel MOSFET
devices, is ideal for applications where dual power
supplies are in continuous use. Typical applications
for this include products with multiple USB ports, or
ports requiring protection that operate from separate
power supplies. The input power supplies can be
any voltage between 2.2V and 5.5V in any combination; one supply is not required to be the higher voltage. Internally, the power supply for the control circuitry will automatically switch to the higher of the two
supplies. In the case where the supplies are equal,
±30mV of hysteresis prevents the internal supply
from oscillating between the two input supplies. The
low impedance P-channel MOSFET devices are
identical in size, allowing for layout flexibility. They
are controlled by a patented fast acting current loop
and respond to short circuits in a fraction of a
microsecond, easing requirements on the input
capacitors. With such fast transient response time,
the upstream power supply rail is naturally isolated
from the protected port.
a high ambient temperature or an over-current condition causes the die temperature to reach the internal thermal limit, both power devices are switched off
until the die temperature cools to a level below the
thermal limit threshold. The device will thermal cycle
indefinitely until the over-current or high temperature
condition is removed. Due to the high thermal conductivity of silicon and the size of the die, the temperature across the die is relatively uniform at high
temperatures; therefore, as a precaution, both power
devices are switched off when the thermal threshold
is reached. Since the power devices operate from
independent power supplies, independent undervoltage lockout circuits are employed. If the power
supply to one channel falls below the under-voltage
lockout threshold, the other channel will remain
active. A current limit condition is reported by the
open drain FAULT output associated with the appropriate channel. A thermal limit condition is reported
by both FAULT outputs. A three millisecond blanking
interval prevents false reporting during the charging
of a capacitive load, which typically occurs during
device turn-on, but may also occur during a port hot
plug-in event.
The AAT4670 is internally protected from thermal
damage by an over-temperature detection circuit. If
The AAT4670 is ideally suited for protection of peripheral ports such as USB, PS2, and parallel ports.
4670.2006.09.1.4
7
AAT4670
Dual-Input, Dual-Output Load Switch
Applications Information
Input Capacitor
The input capacitors, CINA and CINB, protect the
input power supplies from current transients generated by loads attached to the AAT4670. If a short
circuit is suddenly applied to an output of the
AAT4670, there is a 750 nanosecond period during
which a large current flows before current limit circuitry activates. (See characteristic curve "Short
Circuit Through 0.3Ω.") In this event, a properly
sized input capacitor can dramatically reduce the
voltage transient seen by the power supply and
other circuitry upstream from the AAT4670. CIN
should be located as close to the device VIN pin as
practically possible. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for
CIN. There is no specific capacitor equivalent series
resistance (ESR) requirement for CIN. However, for
higher current operation, ceramic capacitors are
recommended for CIN due to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as
batteries in portable devices.
than approximately three milliseconds, the associated FAULT flag is pulled to ground through
approximately 100Ω. Removal of voltage or current transients of less than three milliseconds prevents capacitive loads connected to either
AAT4670 output from activating the associated
FAULT flag when they are initially attached. Pull-up
resistances of 1kΩ to 100kΩ are recommended.
Since FAULT is an open drain terminal, it may be
pulled up to any unrelated voltage less than the
maximum operating voltage of 5.5V, allowing for
level shifting between circuits.
Thermal Considerations
Since the AAT4670 has internal current limit and
over-temperature protection, junction temperature
is rarely a concern. However, if the application
requires large currents in a hot environment, it is
possible that temperature, rather than current limit,
will be the dominant regulating condition. In these
applications, the maximum current available without risk of an over-temperature condition must be
calculated. The maximum internal temperature
while current limit is not active can be calculated
using Equation 1.
Output Capacitor
In order to insure stability while the current limit is
active, a small capacitance of approximately 1µF is
required on each output. No matter how big the
output capacitor, output current is limited to the
value set by the AAT4670 current limiting circuitry,
allowing very large output capacitors to be used.
For example, USB ports are specified to have at
least 120µF of capacitance downstream from their
controlling power switch. The current limiting circuit
will allow an output capacitance of 1000µF or more
without disturbing the upstream power supply.
Attaching Loads
Capacitive loads attached to the AAT4670 will charge
at a rate no greater than the current limit setting.
Eq. 1: TJ(MAX) = IMAX2 · RDS(ON)(MAX) · RΘJA + TA(MAX)
In Equation 1, IMAX is the maximum current
required by the load. RDS(ON)(MAX) is the maximum
rated RDS(ON) of the AAT4670 at high temperature.
RθJA is the thermal resistance between the
AAT4670 die and the board onto which it is mounted. TA(MAX) is the maximum temperature that the
PCB under the AAT4670 would be if the AAT4670
were not dissipating power. Equation 1 can be
rearranged to solve for IMAX; Equation 2.
Eq. 2:
IMAX =
TSD(MIN) - TA(MAX)
RDS(ON)(MAX) · RΘJA
FAULT Output
FAULT flags are provided to alert the system if an
AAT4670 load is not receiving sufficient voltage to
operate properly. If current limit or over-temperature circuits in any combination are active for more
8
TSD(MIN) is the minimum temperature required to
activate the AAT4670 over-temperature protection.
With typical specification of 125°C, 115°C is a safe
minimum value to use.
4670.2006.09.1.4
AAT4670
Dual-Input, Dual-Output Load Switch
For example, if an application is specified to operate in 50°C environments, the PCB operates at
temperatures as high as 85°C. The application is
sealed and its PCB is small, causing RθJA to be
approximately 120°C/W. Using Equation 2:
Eq. 3:
IMAX =
To prevent thermal limiting, the operating load current in the application must be less than 1.25A
which lies in the current limiting range. So, in this
application, any operating current below the current limit threshold is allowed.
115 - 85
= 1.25A
160m · 120
Timing Diagram
EN
OUT
t1
4670.2006.09.1.4
t2
t3
t4
9
AAT4670
Dual-Input, Dual-Output Load Switch
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
SOP-8
4670
AAT4670IAS-T1
TSSOP-8
4670
AAT4670IHS-T1
MSOP-8
BFXYY
AAT4670IKS-T1
TDFN33-12
AAT4670IWP-T1
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 Information
3.90 ± 0.10
6.00 ± 0.20
SOP-8
4.90 ± 0.10
1.27 BSC
45°
4° ± 4°
1.55 ± 0.20
0.42 ± 0.09 × 8
0.175 ± 0.075
0.375 ± 0.125
0.235 ± 0.045
0.825 ± 0.445
All dimensions in millimeters.
1. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
10
4670.2006.09.1.4
AAT4670
Dual-Input, Dual-Output Load Switch
6.40 ± 0.20
4.40 ± 0.10
TSSOP-8
12° REF × 4
3.00 ± 0.10
1.05 MAX
0.245 ± 0.055 × 8
1.20 MAX
0.65 BSC
0.145 ± 0.055
4° ± 4°
0.60 ± 0.15
0.10 ± 0.05
DETAIL A
12°
1.00
REF
All dimensions in millimeters.
4670.2006.09.1.4
11
AAT4670
Dual-Input, Dual-Output Load Switch
MSOP-8
4° ± 4°
4.90 ± 0.10
3.00 ± 0.10
1.95 BSC
0.95 REF
0.60 ± 0.20
PIN 1
3.00 ± 0.10
0.85 ± 0.10
0.95 ± 0.15
10° ± 5°
GAUGE PLANE
0.254 BSC
0.155 ± 0.075
0.075 ± 0.075
0.65 BSC
0.30 ± 0.08
All dimensions in millimeters.
12
4670.2006.09.1.4
AAT4670
Dual-Input, Dual-Output Load Switch
TDFN33-12
2.40 ± 0.05
Detail "B"
3.00 ± 0.05
Index Area
(D/2 x E/2)
0.3 ± 0.10 0.16 0.375 ± 0.125
0.075 ± 0.075
3.00 ± 0.05
1.70 ± 0.05
Top View
Bottom View
Pin 1 Indicator
(optional)
0.23 ± 0.05
Detail "A"
0.45 ± 0.05
0.1 REF
0.05 ± 0.05
0.229 ± 0.051
+ 0.05
0.8 -0.20
7.5° ± 7.5°
Option A:
C0.30 (4x) max
Chamfered corner
Side View
Option B:
R0.30 (4x) max
Round corner
Detail "B"
Detail "A"
All dimensions in millimeters.
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830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
4670.2006.09.1.4
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