Datasheet AAT4670IKS-T1, AAT4670IKS-B1, AAT4670IHS-T1, AAT4670IHS-B1, AAT4670IAS-T1 Datasheet (Analogic Technologies)

AAT4670

Dual-Input, Dual-Output Load Switches

General Description

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.

The AAT4670 is available in 8 pin SOP, TSSOP or
MSOP specified over -40 to 85 °C temperature
range.

SmartSwitch

Features

• 2.2V to 5.5V input voltage range

• 1A current limit per channel

• 95mΩ typical R

• 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

Applications

• Notebook Computer

• PDA, Subnotebook

• USB ports

• Peripheral ports

• Hot swap supplies

• Media bay

DS(ON)

™

Preliminary Information

Typical Application

INA
INB
EN

AAT4670

FAULTA

FAULTB

GND

4

OUTA
OUTB

8

5

2

3

FAULTA
FAULTB

C

OUTA

1µF

OUTA

OUTB

C

OUTB

1µF

INA
INB

C

INA

1µF

EN

C

1µF

7

6

1

INB

GND GND

4670.2002.1.0.92 1

AAT4670

Dual-Input, Dual-Output Load Switches

Pin Descriptions

Pin # Symbol Function

1 EN Active-low Enable input (Logic low turns the switches on)

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 P-channel MOSFET drain channel B

Pin Configuration

EN

FAULTA
FAULTB

GND

SOP-8 TSSOP-8 MSOP-8

1 2

1

2

3

4

8

OUTB

7

INB

6

INA

5

OUTA

EN

FAULTA
FAULTB

GND

1 2

1

2

3

4

8

OUTB

7

INB

6

INA

5

OUTA

EN

FAULTA
FAULTB

GND

1

2

3

4

1 2

8

OUTB

7

INB

6

INA

5

OUTA

2 4670.2002.1.0.92

AAT4670

Dual-Input, Dual-Output Load Switches

Absolute Maximum Ratings (T

=25°C unless otherwise noted)

A

Symbol Description Value Units

V

INA,B

V

OUTA,B

V

FAULTA,B

I

OUT

T

J

V

ESD

T

LEAD

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.

INA or INB to GND -0.3 to 6 V
OUTA or OUTB to GND -0.3 to 6 V
FAULTA or FAULTB to GND -0.3 to 6 V
Output Current Internally Limited A
Operating Junction Temperature Range -40 to 150 °C
ESD Rating1- HBM 4000 V
Maximum Soldering Temperature (at Leads) 300 °C

Thermal Characteristics

Symbol Description Value Units

Θ

JA

P

D

Note 2: Mounted on a demo board.

Electrical Characteristics (V

-40 to 85°C temperature range)

Maximum Thermal Resistance2(SOP-8) 100 °C/W
Maximum Power Dissipation2(SOP-8) 1.25 W

= 5V, TA= 25°C unless otherwise noted. Bold values designate

IN

Symbol Description Conditions Min Typ Max Units

V

I

I

Q(OFF)

I

SD(OFF)

V

UVLO

R

DS(ON)

T

CRDS

I

LIM

t
t
t
t

V

EN(L)

V

EN(H)

I

EN(SINK)

t

RESP

V

FAULTLOW

I

SINK

T

blank

T

Note 3: For VINoutside this range consult typical EN threshold curve.

Operation Voltage 2.2 5.5 V

IN

Quiescent Current V

Q

Off Supply Current EN = VIN, V
Off Switch Current EN = VIN, V

INA

or V

INB

INA=VINB

INA=VINB

= 5V I

OUTA

= I

= 0 18 40 µA

OUTB

=5V, OUTA, OUTB open 1 µA
=5V, V

OUTA=VOUTB

=0V 0.1 1 µA

Undervoltage Lockout 1.7 2.2 V

V

=5.0V 95 130

On-Resistance Channel A or B

IN

VIN=3.0V 105 150
Switch Resistance Tempco 2800 ppm/°C
Current Limit Channel A or B V
Output Turn-On Delay Time VIN=5V, OUT=0 to 10%, R

1

Output Rise Time VIN=5V, OUT=10% to 90%, R

2

Output Turn-Off Delay Time VIN=5V, OUT=100% to 90%, R

3

Output Fall Time VIN=5V, OUT=90% to 10%, R

4

EN Input Low Voltage VIN=2.7V to 5.5V

EN Input High Voltage

< VIN- 0.5V 1.0 1.25 1.50 A

OUT

=20Ω 100 1000 µs

LOAD

=20Ω 100 1000 µs

LOAD

=20Ω 10 20 µs

LOAD

=20Ω 5 20 µs

3

V

=2.7V to <3.6V 2.0

IN

LOAD

VIN=3.6V to 5.5V 2.4
EN Input Leakage VEN=5.5V 0.01 1 µA
Current Loop Response VIN=5V 750 ns
FAULT logic Output Low I
FAULT Logic Output High V

= 1mA 0.4 V

SINK

= 5.5V 0.5 1 µA

FAULT

Leakage Current
Fault Blanking Time 3 ms
Over-temperature threshold 125 °C

SD

mΩ

0.8 V

V

4670.2002.1.0.92 3

Typical Characteristics

AAT4670

Dual-Input, Dual-Output Load Switches

Quiescent Current vs. Temperature

30

25

20

15

10

5

Quiescent Current (µA)

0

-40 -20 0 20 40 60 80 100 120

Temperature (°C)

Off-Supply Current vs. Temperature

1.0000

0.1000

0.0100

0.0010

Quiescent Current vs. Input Voltage

20

18

16

14

12

10

8

Input (µA)

6

4

2

0

0 1234 56

Input (V)

Off-Switch Current vs. Temperature

1.0000

0.1000

0.0100

0.0010

0.0001

Off-Switch Current (µA)

0.0000

-40 -20 0 20 40 60 80 100 120

Temperature (°C)

Current Limit vs. Output Voltage

1.4

1.2

1.0

0.8

0.6

0.4

Output (A)

0.2

0.0
012345

Output (V)

0.0001

Off-Switch Current (µA)

0.0000

-40 -20 0 20 40 60 80 100 120

Temperature (°C)

R

vs. Temperature

DS(ON)

150

140

130

120

110

(mΩ)

100

DS(ON)

90

R

80

70

60

-40 -20 0 20 40 60 80 100 120

VIN=3V

VIN=5V

Temperature (°C)

4 4670.2002.1.0.92

Typical Characteristics

AAT4670

Dual-Input, Dual-Output Load Switches

Turn-ON/OFF Response with 20Ω 1µF loads

EN (5V/div)

FAULT (5V/div)

OUTB (5V/div) INB = 5V

OUTA (5V/div) INA = 3V

I

+ I

(200mA/div)

INA

INB

100µs/div

Short Circuit Through 0.6Ω

8

6

4

2

Input and Output (V)

0

-10 1234

Input Voltage

Output Current

Output Voltage

Time (µs)

9

6

3

0

-3

Output (A)

FAULT Delay

Start Into 0.6Ω Load

ON (5V/div)

FAULT (5V/div)

V

(1V/div)

OUT

IIN (500mA/div)

500µs/div

Short Circuit Through 0.3Ω

8

6

4

2

0

Input and Output (V)

-2

-1 0 1 2 3 4

Time (µs)

Input Voltage

Output Current

Output Voltage

12

8

4

0

-4

Output (A)

Thermal Shutdown Response

ON (5V/div)

FAULT (5V/div)

V

(1V/div)

OUT

IIN (500mA/div)

200ms/div

2.4

2.2

2

1.8

1.6

1.4

1.2

EN Threshold (V)

1

0.8

0.6

Typical EN Threshold vs. V

V

EN(H)

V

EN(L)

1.5 2 2.5 3 3.5 4 4.5 5 5.5

V

(V)

IN

IN

4670.2002.1.0.92 5

Functional Block Diagram

INA OUTA

AAT4670

Dual-Input, Dual-Output Load Switches

UVLO

OTMP

UVLO

INB

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

I

LIM

I

LIM

Slew
Rate

EN

Slew
Rate

OUTB

FAULTA

FAULTB

GND

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.

6 4670.2002.1.0.92

AAT4670

Dual-Input, Dual-Output Load Switches

Applications Information

Input Capacitor

The input capacitors, C
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 capaci-

tor can dramatically reduce the voltage transient
seen by the power supply and other circuitry
upstream from the AAT4670. CINshould be located
as close to the device VINpin 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 CINdue 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 cur-
rent transients of less than three milliseconds pre­vents capacitive loads connected to either

INA

and C

, protect the input

INB

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.

T

J(MAX)

In Equation 1, I
required by the load. R
mum rated R
ature. R
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 I

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 R
approximately 120°C/W. Using Equation 2,

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.

2

= I

× R

MAX

DS(ON)

is the thermal resistance between the

θJA

I

=

MAX

I

=

MAX

(MAX) × R

DS(ON)

is the maximum current

MAX

(MAX) is the maxi-

DS(ON)

+ TA(MAX)

θJA

of the AAT4670 at high temper-

; Equation 2.

MAX

(MIN) - TA(MAX)

T

SD

R

160m × 120

DS(ON)

115 - 85

(MAX) × R

= 1.25 A

θJA

θJA

to be

4670.2002.1.0.92 7

Timing Diagram

EN

OUT

AAT4670

Dual-Input, Dual-Output Load Switches

t1 t2 t3 t4

Ordering Information

Package Marking

SOP-8 AAT4670IAS-B1 AAT4670IAS-T1

TSSOP-8 AAT4670IHS-B1 AAT4670IHS-T1

MSOP-8 AAT4670IKS-B1 AAT4670IKS-T1

Bulk Tape and Reel

Part Number

8 4670.2002.1.0.92

Package Information

SOP-8

AAT4670

Dual-Input, Dual-Output Load Switches

y

7 (4x)

Dim

Millimeters Inches

Min Max Min Max

A 1.35 1.75 0.053 0.069

E

H

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

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

A

A2

A1

e

b

Θ

L

c

θ10° 8° 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.

4670.2002.1.0.92 9

TSSOP-8

AAT4670

Dual-Input, Dual-Output Load Switches

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

c 0.127 0.005

E

E1

DETAIL A

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

R 0.09 - 0.004 -

R1 0.09 - 0.004 -

θ10° 8° 0° 8°

D

e

A2

E

0.20

R1

A

R

θ1

θ2 12°

b

A1

DETAIL A

θ2

L

L1

10 4670.2002.1.0.92

MSOP-8

AAT4670

Dual-Input, Dual-Output Load Switches

PIN 1

e1

e1 t1

t

Dim

Millimeters Inches

Min Max Min Max

A 0.08 1.10 0.003 0.043
A1 0.00 0.15 0.000 0.005
A2 0.75 0.95 0.029 0.037

b 0.22 0.38 0.008 0.014

E1

E

C 0.08 0.23 0.003 0.009
D 2.90 3.10 0.114 0.122

E 4.80 5.00 0.188 0.196
E1 2.90 3.10 0.114 0.122

(1)

L

L1

D

t1

C

e 0.65 BSC 0.025 BSC

e1 1.95 BSC 0.076 BSC

L 0.40 0.80 0.015 0.031

L1 0.95 REF 0.037 REF
L2 0.254 BSC 0.010 BSC

A

e

A1

A2

b

GAUGE PLANE

θ 0° 8° 0° 8°

θ2 5° 15° 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.

4670.2002.1.0.92 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 [phone]
Fax [phone]

12 4670.2002.1.0.92