Analogic AAT4670IAS-B1 Dual-input, dual-output load switch Datasheet

AAT4670
Dual-Input, Dual-Output Load Switches
General Description
Features
The AAT4670 SmartSwitch™ is part of the Analogic
Tech Application Specific Power MOSFET
(ASPM™) line of products. 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.
•
•
•
•
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
Temp range -40 to 85ºC
8-pin SOP, TSSOP or MSOP packages
Preliminary Information
•
•
•
•
•
•
•
•
SmartSwitch™
Applications
•
•
•
•
•
•
Notebook Computer
PDA, Subnotebook
USB ports
Peripheral ports
Hot swap supplies
Media bay
The AAT4670 is available in 8 pin SOP, TSSOP or
MSOP specified over -40 to 85 °C temperature
range.
Typical Application
AAT4670
7
INA
INB
6
EN
1
INA
INB
EN
GND
CINA
1µF
GND
4670.2002.1.0.92
CINB
1µF
4
OUTA
OUTB
FAULTA
FAULTB
8
OUTA
OUTB
5
2
3
FAULTA
FAULTB
COUTA
1µF
COUTB
1µF
GND
1
AAT4670
Dual-Input, Dual-Output Load Switches
Pin Descriptions
Pin #
Symbol
Function
1
EN
2
FAULTA
Open drain output signals over-current for OUTA and over-temperature condition
3
FAULTB
Open drain output signals over-current for OUTB and over-temperature condition
4
GND
Ground connection
5
OUTA
P-channel MOSFET drain channel A
6
INA
P-channel MOSFET source channel A
7
INB
P-channel MOSFET source channel B
8
OUTB
Active-low Enable input (Logic low turns the switches on)
P-channel MOSFET drain channel B
Pin Configuration
SOP-8
5
FAULTA
FAULTB
GND
2
8
7
3
6
4
5
OUTB
INB
INA
OUTA
EN
1
FAULTA
FAULTB
GND
2
8
7
2
6
4
1
1
3
EN
MSOP-8
2
7
OUTB
INB
INA
OUTA
1
FAULTA
FAULTB
GND
2
8
2
1
1
2
EN
TSSOP-8
3
6
4
5
OUTB
INB
INA
OUTA
4670.2002.1.0.92
AAT4670
Dual-Input, Dual-Output Load Switches
Absolute Maximum Ratings
(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 Rating1 - 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
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
ΘJA
PD
Description
Maximum Thermal Resistance2 (SOP-8)
Maximum Power Dissipation2 (SOP-8)
Value
Units
100
1.25
°C/W
W
Note 2: Mounted on a demo board.
Electrical Characteristics
(VIN = 5V, TA = 25°C unless otherwise noted. Bold values designate
-40 to 85°C temperature range)
Symbol Description
VIN
IQ
Conditions
IQ(OFF)
ISD(OFF)
VUVLO
Operation Voltage
Quiescent Current
Off Supply Current
Off Switch Current
Undervoltage Lockout
VINA or VINB = 5V IOUTA = IOUTB = 0
EN = VIN, VINA=VINB =5V, OUTA, OUTB open
EN = VIN, VINA=VINB =5V, VOUTA=VOUTB =0V
RDS(ON)
On-Resistance Channel A or B
VIN=5.0V
VIN=3.0V
TCRDS
ILIM
t1
t2
t3
t4
VEN(L)
Switch Resistance Tempco
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
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
VOUT < VIN - 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 5.5V3
VIN=2.7V to <3.6V
VIN=3.6V to 5.5V
VEN=5.5V
VIN=5V
ISINK = 1mA
VFAULT = 5.5V
Min Typ
Max Units
2.2
5.5
40
1
1
2.2
130
150
18
1.0
V
µA
µA
µA
V
0.1
1.7
95
mΩ
105
2800
ppm/°C
1.25 1.50
A
100 1000
µs
100 1000
µs
10
20
µs
5
20
µs
0.8
V
2.0
2.4
V
0.01
750
0.5
3
125
1
0.4
1
µA
ns
V
µA
ms
°C
Note 3: For VIN outside this range consult typical EN threshold curve.
4670.2002.1.0.92
3
AAT4670
Dual-Input, Dual-Output Load Switches
Typical Characteristics
Quiescent Current vs. Temperature
Quiescent Current vs. Input Voltage
20
18
25
16
20
14
Input (µA)
Quiescent Current (µA)
30
15
10
6
4
5
2
0
0
-40
-20
0
20
40
60
80
100
120
0
1
2
3
4
5
6
Temperature (°C)
Input (V)
Off-Supply Current vs. Temperature
Off-Switch Current vs. Temperature
1.0000
Off-Switch Current (µA)
1.0000
Off-Switch Current (µA)
12
10
8
0.1000
0.0100
0.0010
0.0001
0.0000
0.1000
0.0100
0.0010
0.0001
0.0000
-40
-20
0
20
40
60
80
100
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
RDS(ON) (mΩ)
Output (A)
1.0
0.8
0.6
0.4
130
120
VIN=3V
110
100
90
VIN=5V
80
0.2
70
0.0
60
0
1
2
3
Output (V)
4
4
5
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
4670.2002.1.0.92
AAT4670
Dual-Input, Dual-Output Load Switches
Typical Characteristics
Turn-ON/OFF Response with 20Ω 1µF loads
FAULT Delay
Start Into 0.6Ω Load
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)
100µs/div
500µs/div
Short Circuit Through 0.3Ω
Short Circuit Through 0.6Ω
4
6
3
Output Current
2
0
Output Voltage
0
Input and Output (V)
Input Voltage
6
8
0
1
2
3
Input Voltage
6
8
4
4
Output Current
2
0
0
Output Voltage
-3
-1
12
Output (A)
9
Output (A)
Input and Output (V)
8
-2
4
-4
-1
0
1
Time (µs)
2
3
4
Time (µs)
Typical EN Threshold vs. VIN
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
200ms/div
4670.2002.1.0.92
2
2.5
3
3.5
4
4.5
5
5.5
VIN (V)
5
AAT4670
Dual-Input, Dual-Output Load Switches
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 off of 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, which eases requirements on the input capacitors. With such fast transient response time, the
upstream power supply rail is naturally isolated from
the protected port. The AAT4670 is internally protected from thermal damage by an over temperature
detection circuit. If a high ambient temperature or an
6
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, and therefore, as a precaution, both power devices are switched off when
the thermal threshold is reached. Since the power
devices operate off of independent power supplies,
independent under voltage 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 ideally suited for protection of peripheral ports such as USB, PS2 and parallel ports.
4670.2002.1.0.92
AAT4670
Dual-Input, Dual-Output Load Switches
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 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.
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 down stream 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.
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
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
4670.2002.1.0.92
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.
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.
IMAX=
TSD(MIN) - TA(MAX)
RDS(ON)(MAX) × RθJA
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.
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,
IMAX=
115 - 85
= 1.25 A
160m × 120
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.
7
AAT4670
Dual-Input, Dual-Output Load Switches
Timing Diagram
EN
OUT
t1
t2
t3
t4
Ordering Information
Package
8
Marking
Part Number
Bulk
Tape and Reel
SOP-8
AAT4670IAS-B1
AAT4670IAS-T1
TSSOP-8
AAT4670IHS-B1
AAT4670IHS-T1
MSOP-8
AAT4670IKS-B1
AAT4670IKS-T1
4670.2002.1.0.92
AAT4670
Dual-Input, Dual-Output Load Switches
Package Information
SOP-8
Dim
E H
D
7 (4x)
A
c
A2
b
y
4670.2002.1.0.92
e
A1
Θ
L
A
A1
A2
B
C
D
E
e
H
L
Y
θ1
Millimeters
Min
Max
1.35
1.75
0.10
0.25
1.45
0.33
0.51
0.19
0.25
4.80
5.00
3.80
4.00
1.27
5.80
6.20
0.40
1.27
0.00
0.10
0°
8°
Inches
Min
Max
0.053
0.069
0.004
0.010
0.057
0.013
0.020
0.007
0.010
0.189
0.197
0.150
0.157
0.050
0.228
0.244
0.016
0.050
0.000
0.004
0°
8°
Note:
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.
9
AAT4670
Dual-Input, Dual-Output Load Switches
TSSOP-8
Dim
E
D
DETAIL A
E1
A
A1
A2
b
c
D-8
D-28
E
E1
e
L
L1
R
R1
θ1
θ2
Millimeters
Min
Max
1.05
1.20
0.05
0.15
1.05
0.25
0.30
0.127
2.90
3.10
9.60
9.80
4.30
4.50
6.20
6.60
0.65 BSC
0.50
0.70
1.0
0.09
0.09
0°
8°
Inches
Min
Max
0.041
0.047
0.002
0.006
0.041
0.010
0.012
0.005
0.114
0.122
0.378
0.386
0.170
0.177
0.244
0.260
0.025 BSC
0.20
0.028
0.039
0.004
0.004
0°
8°
12°
E
0.20
e
R1
A2
A
R
θ1
A1
L
b
DETAIL A
10
θ2
L1
4670.2002.1.0.92
AAT4670
Dual-Input, Dual-Output Load Switches
MSOP-8
t
e1
E1
E
PIN 1
L
D
t1
A2
A
e
4670.2002.1.0.92
b
GAUGE PLANE
L1
A1
Dim
e1 t1
C
(1)
A
A1
A2
b
C
D
E
E1
e
e1
L
L1
L2
θ
θ2
Millimeters
Min
Max
0.08
1.10
0.00
0.15
0.75
0.95
0.22
0.38
0.08
0.23
2.90
3.10
4.80
5.00
2.90
3.10
0.65 BSC
1.95 BSC
0.40
0.80
0.95 REF
0.254 BSC
0°
8°
5°
15°
Inches
Min
Max
0.003
0.043
0.000
0.005
0.029
0.037
0.008
0.014
0.003
0.009
0.114
0.122
0.188
0.196
0.114
0.122
0.025 BSC
0.076 BSC
0.015
0.031
0.037 REF
0.010 BSC
0°
8°
5°
15°
Note:
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.
11
AAT4670
Dual-Input, Dual-Output Load Switches
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Advanced Analogic Technologies, Inc.
1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086
Phone (408) 524-9684
Fax (408) 524-9689
12
4670.2002.1.0.92
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