Datasheet AAT4650IHS-T1, AAT4650IHS-B1, AAT4650IAS-T1, AAT4650 Datasheet (Analogic Technologies)

AAT4650

5V/3V PC Card Power Switch

General Description

The AAT4650 SmartSwitch™ is a single channel PC
Card (PCMCIA) power switch. It is used to select
between two different voltage inputs, each between

2.7V and 5.5V. An internal switch powers the cir­cuitry from whichever input voltage is higher. The
device's output, VCC, is slew rate controlled and cur­rent limited, in compliance with PC Card specifica­tions. The current limit response time to a short cir­cuit is typically 1µs. The internal P-Channel MOS­FET switches are configured to break before make,
that is, both switches cannot be closed at the same
time. Controlled by a 2 bit parallel interface, the four
states for V
Ground. When in the ground state, VCCis pulled to

ground by a 5kΩ resistor. An open drain FAULT out-

put is asserted during over-current conditions.
During power up slewing, FAULT also signals that
V

is out of tolerance. An internal over temperature

CC

sensor forces VCCto a high impedance state when
an over-temperature condition exists. Quiescent
current is typically a low 15µA, as long as ICCis less
than approximately 500mA. Above this load current,
the quiescent current increases to 200µA.

are VCC5, VCC3, Hi-impedance, or

CC

SmartSwitch

Features

• 2.7V to 5.5V Input voltage range

• 85mΩ (5V) typical R

• Low quiescent current 15µA (typ)

• Reverse-blocking switches

• Short-circuit protection

• Over-temperature protection

• FAULT flag output

• Temp range -40 to 85°C

• 8 pin SOP or TSSOP package

Applications

• Notebook Computer

• PDA, Subnotebook

• Power Supply Multiplexer Circuit

DS(ON)

™

Preliminary Information

The AAT4650 is available in 8-pin SOP and
TSSOP packages specified over -40 to 85°C.

Typical Application

VCC5

CC3

V

CTL1
CTL0

FAULT

CIN5

1µF

CIN3

1µF

GND GND

8

5

3

2

4

1

VCC5

V

CC3

CTL1
CTL0
FAULT
GND

AAT4650

V

CC

6,7

COUT

0.1µF

VCC

4650.2001.10.0.93 1

CTL1

CTL0

1 2

VCC5
V

CC

V

CC

VCC3

GND

FAULT

5V/3V PC Card Power Switch

Pin Descriptions

Pin # Symbol Function

1 GND Ground connection

2 CTL0 Control input (see Control Logic Table below)

3 CTL1 Control input (see Control Logic Table below)

4 FAULT Open drain output signals over-current condition

AAT4650

5V

3 3V supply

CC

6VCCOutput (see Control Logic Table below)

7VCCOutput (see Control Logic Table below)

8V

5 5V supply

CC

Pin Configuration

SO-8 / TSSOP-8

(Top View)

1

2

3

4

8

7

6

5

Control Logic Table

CTL1 CTL0 Function Result

0 0 OFF 5k VCCto GND

01 5v V

10 3v V

CC=VCC

CC=VCC

1 1 HiZ Both FETs OFF

2 4650.2001.10.0.93

5

3

AAT4650

5V/3V PC Card Power Switch

Absolute Maximum Ratings (T

=25°C unless otherwise noted)

A

Symbol Description Value Units

VCC3, VCC5 IN to GND -0.3 to 6 V

V

CC

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.

OUT to GND -0.3 to 6 V
Maximum Continuous Switch Current Current Limited A
Operating Junction Temperature Range -40 to 150 °C
Maximum Soldering Temperature (at Leads) 300 °C
ESD Rating1— HBM 4000 V

Thermal Characteristics

Symbol Description Value Units

Θ

JA

P

D

Note 2: Mounted on an FR4 board.

Thermal Resistance (SOP-8)
Power Dissipation (SOP-8)

Electrical Characteristics (V

are at TA=25°C; bold values designate full temperature range)

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

VCCOutput

I

Hi-Z High impedance Output OFF mode, VCC=0V 1 µA

CC

Iccsc Short Circuit Current Limit V

R

DS(ON)

Tcrds Switch Resistance Tempco 2800 ppm/ºC

VCCSwitching Time (Refer to Figure 1)

t1 Output Turn-On Delay Time VCC=0v to 10% of 3.3V, R
t2 Output Turn-On Delay Time VCC=0v to 10% of 5.0V, R
t3 Output Rise Time VCC=10% to 90% of 3.3V, R
t4 Output Rise Time VCC=10% to 90% of 5.0V, R
t5 Output Turn-Off Delay Time VCC=3.3 to 90% of 3.3V, R
t6 Output Turn-Off Delay Time VCC=5.0 to 90% of 5.0V, R
t7 Output Fall Time to OFF State VCC=90% to 10% of 3.3V, R
t8 Output Fall Time to OFF State VCC=90% to 10% of 5.0V, R
t9 Output Fall Time to Hi-Z State VCC=90% to 10% of 3.3V, R
t10 Output Fall Time to Hi-Z State V

Leakage Current

On-Resistance

CC=VCCIN

-0.5V, ON mode VCC3 1.0 2.0 A

or VCC5 selected, TA=25°C
V

=3.0v, TA=25°C 85 110 mΩ

CC

VCC=5.0v, TA=25°C 80 100 mΩ

=10Ω 500 2000 µs

OUT

=10Ω 500 1500 µs

OUT

=10Ω 300 1000 3000 µs

LOAD

=10Ω 300 1000 3000 µs

LOAD

=10Ω 400 µs

LOAD

=10Ω 400 µs

LOAD

=10Ω 200 µs

LOAD

=10Ω 200 µs

LOAD

=10Ω 1500 µs

LOAD

=90% to 10% of 5.0V, R

CC

=10Ω 2000 µs

LOAD

4650.2001.10.0.93 3

AAT4650

5V/3V PC Card Power Switch

Symbol Description Conditions Min Typ Max Units

Power Supply

VCC3V
VCC5V

ICC3V

ICC5V

Parallel Interface

V

CTLLOW

V

CTLHI

I

SINKCTL

V

FAULTLOW

I

SINKFAULT

Other

OTMP Over Temperature Shutdown 125 degC

3 Operation Voltage 2.7 5.5 V

CC

5 Operation Voltage 2.7 5.5 V

CC

V

=5V or HiZ or OFF, 1 µA

3 Supply Current VCC3<VCC5, ICCOut=0

CC

CC

VCC=3.3v, VCC3<VCC5, ICCOut=0 5 20 µA

=Off, VCC5>VCC3, ICCOut=0 1 µA

V

CC

5 Supply Current

CC

VCC=HiZ, VCC5>VCC3, ICCOut=0 10 40 µA
VCC=3.3v, VCC5>VCC3 ,ICCOut=0 10 40 µA
VCC=5v, VCC5>VCC3, ICCOut=0 15 40 µA

CTL Input Low Voltage 0.8 V
CTL Input High Voltage VCC3 or VCC5=2.7 to 3.6V 2.0 V

VCC3 or VCC5=4.5 to 5.5V 2.4 V
CTL Input leakage V
FAULT Logic Output Low I

= 5.5V 0.01 1 µA

CTL

=1mA 0.4 V

SINK

Voltage
FAULT Logic Output High V

= 5.5V 0.05 1 µA

FAULT

Leakage Current

Timing Diagram

5

0

5

0

Figure 1: VCCSwitching Time Diagram

Refer to VCCSwitching Time specifications under the Electrical Characteristics section for definitions of t1
to t10.

CTL0,1

Vcc

t1, t2 t5, t6 t7, t8

t3, t4

t9, t10

4 4650.2001.10.0.93

Typical Characteristics

(Unless otherwise noted, TA= 25°C)

AAT4650

5V/3V PC Card Power Switch

Quiescent Current vs. Temperature

(I

5)

CC

30

25

VCC3=3V

5=5V

V

20

CC

15

10

5

0

Quiescent Current (µA)

-40 -20 0 20 40 60 80 100 120

CTL0=5V
CTL1=0V

Temperature (C)

Current Limit VCC=VCC5

2

Ta=25C

1.5

1

0.5

0

0123456

Vout

Current Limit VCC=VCC3

2

1.5

0.5

Ta=25C

1

0

00.511.522.53

Vout

Off-Switch Current vs. Temperature (ICC3)

1.0000

VCC3=3V
V

5=5V

CC

-40 -20 0 20 40 60 80 100 120

Off-Switch Current (µA)

0.1000

0.0100

0.0010

0.0001

0.0000

CTL1=0V
CTL0=0V

Temperature (C)

Off-Switch Current vs. Temperature ICC5

1.0000

VCC5=5V

0.1000

V

3=3V

CC

0.0100

0.0010

0.0001

Off-Switch Current (µA)

0.0000

-40 -20 0 20 40 60 80 100 120

CTL1=0V
CTL0=0V

Temperature (C)

120.0

110.0

100.0

90.0

80.0

70.0

60.0

Rdson vs. Temperature

VCC=VCC3=3.0V

V

-40-200 20406080100120

Temperature (C)

CC=VCC

5=5.0V

4650.2001.10.0.93 5

(Unless otherwise noted, TA= 25°C)

AAT4650

5V/3V PC Card Power Switch

Turn-ON/OFF Response with 10

Ohm 1µF load

CTL1 (5V/div)

FAULT (5V/div)

VCC(2V/div)

I

VCC3

500µs/div

(200mA/div)

Thermal Shutdown Response

(5V/div)

CTL1

FAULT (5V/div)

VCC(1V/div)

I

(500mA/div)

VCC5

100ms / div

Turn-ON/OFF Response with 15

Ohm 1µFload

CTL0 (5V/div)

FAULT (5V/div)

VCC(2V/div)

I

(200mA/div)

VCC5

500µs/div

Short Circuit Through 0.3 Ohm

8

Time

(µs)

Input Voltage

Output Current

Output Voltage

6

4

2

Input and Output (V)

0

-202 46810

11

8

5

2

-1

Output (A)

Short Circuit Through 0.6 Ohm

8

6

4

2

Input and Output (V)

0

-20246810

Input Voltage

Output Current

Output Voltage

Time (µs)

9

6

3

Output (A)

0

-3

6 4650.2001.10.0.93

Functional Block Diagram

AAT4650

5V/3V PC Card Power Switch

CTL1
CTL0

Over

Temperature

Control

Logic

VCC3V

Body Ctl

Over

Current

Slew
Rate

5

CC

Over

Current

Slew
Rate

GND

5KΩ

V

CC

FAULT

Functional Description

ing circuit will slowly slew the V

output to the new

CC

voltage level which protects the upstream power

The AAT4650 is a single channel power switch that
can be used in any application where dual power
supply multiplexing is required. Typical applications
for this include PC card applications not requiring a
12 volt power supply, or applications where power is
switched, for example, between 5 volts for operation
and 3.3 volts for standby mode. The AAT4650 oper­ates with input voltages ranging from 2.7 to 5.5 volts
in any combination and automatically powers its
internal circuitry off of whichever input voltage is
higher. Two identical low RDSP-channel MOSFETS
serve as the power multiplexing circuit with a com­mon drain as the Vcc output and independent
sources as the two Vcc3 and Vcc5 inputs. A two bit
parallel interface determines the state of the multi­plexer: Vcc=Vcc3, Vcc=Vcc5, Vcc with resistive pull
down to ground, or Vcc hi-impedance. When the
state is set to either of the two inputs, the multiplex-

4650.2001.10.0.93 7

supply from sudden load transients. When the
resistive pull down is chosen for VCC, the VCCoutput
is quickly discharged by the resistive pull down.
The AAT4650 always serves as an electronic fuse
by limiting the load current if it exceeds the current
limit threshold. During power up into a short, the
current will gradually increase until the current limit
is reached. During a sudden short circuit on the out­put, the current limit will respond in 1 µs to isolate
and protect the upstream power supply from the
load short circuit. In most applications, because the
response time is so fast, a short circuit to VCCwill
not affect the upstream supply, so system function­ality will not be affected. In the case of an over cur­rent condition, an open drain FAULT flag output will
signal the event. The FAULT output is also active
during output voltage slew, and becomes inactive
once the output is within regulation.

AAT4650

5V/3V PC Card Power Switch

Applications Information

Input Capacitor

Typically a 1µF or larger capacitor is recommended
for CIN. A CINcapacitor is not required for basic
operation, however, it is useful in preventing load
transients from affecting up stream circuits. C
should 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 C
inherent capability over tantalum capacitors to with­stand input current surges from low impedance
sources such as batteries in portable devices.

Output Capacitor

A 0.1µF or greater capacitor is generally required
between Vcc and GND. Likewise, with the output
capacitor, there is no specific capacitor ESR
requirement. If desired, C

may be increased to

OUT

accommodate any load transient condition.

Parallel Interface / Break Before Make

A two bit parallel interface determines the state of
the Vcc output. The logic levels are compatible with
CMOS or TTL logic. A logic low value must be less
than 0.8 volts, and a logic high value must be greater
than 2.4 volts. In cases where the interface pins rap­idly change state directly from 3v to 5v (or vice
versa), internal break before make circuitry prevents
any back flow of current from one input power sup­ply to the other. In addition, the body connections of
the internal P-channel MOSFET switches are
always set to the highest potential of Vcc3, Vcc5, or
Vcc, which prevents any body diode conduction,
power supply backflow, or possible device damage.

FAULT Output

The FAULT output is pulled to ground by an open
drain N-channel MOSFET during an over current or
output slew condition. It should be pulled up to the
reference power supply of the controller IC via a

nominal 100KΩ resistor.

Voltage Regulation

The PC Card Specification calls for a regulated 5
volt supply tolerance of +/-5%. Of this, a typical
power supply will drop less than 2%, and the PCB
traces will drop another 1%. This leaves 2% for the
AAT4650 as the PC card switch. In the PC card
application, the maximum allowable current for the

due to their

IN

AAT4650 is dominated by voltage regulation rather
than by thermal considerations, and is set by either
the current limit or the maximum R

of the P-chan-

DS

nel MOSFET. The maximum RDSat 85°C is calcu­lated by applying the RDSTempco to the maximum
room temperature RDS:

R

IN

R

DS(MAX)

DS(MAX)

= R

x (1 + TC x ∆T), or

DS25

= 105mΩ x (1 + 0.0028 x 60) = 122mΩ

The maximum current is equal to the 2% tolerance
of the 5 volt supply (100mV) across the AAT4650
divided by R

I

MAX5

. Or

DS(MAX)

= 100mV / 122mΩ = 820mA

For the 3.3 volt supply in the PC card application,
the conditions are a bit relaxed, with the allowable
voltage regulation drop equal to 300mV. With a 2%
supply, and 1% PCB trace regulation, the PC card
switch can have a 200mV drop. So

I

= 200mV / 134mΩ = 1.5A

MAX3

Since 1.5A is the nominal current limit value, the
AAT4650 will current limit before I

MAX3

is reached.

Thermal issues are not a problem in the SO-8 pack-

age since Θ

, the package thermal resistance, is

JA

only 120°C/W. At any given ambient temperature
(TA) the maximum package power dissipation can
be determined by the following equation:

P

D(MAX)

= [T

J(MAX)

- T

] / Θ

A

JA

Constants for the AAT4650 are maximum junction
temperature, T

resistance, Θ

JA

= 125°C, and package thermal

J(MAX)

= 120°C/W. Worst case conditions
are calculated at the maximum operating tempera­ture where TA= 85°C. Typical conditions are cal­culated under normal ambient conditions where T
= 25°C. At TA= 85°C, P
25°C, P

D(MAX)

= 833mW.

= 333mW. At TA=

D(MAX)

A

Maximum current is given by the following equation:

I

OUT(MAX)

= (P

D(MAX)

For the AAT4650 at 85°C, I

OUT(MAX)

/ RDS)

1/2

= 1.65A, a
value greater than the internal minimum current
limit specification.

Overcurrent and Overtemperature
Protection

Because many AAT4650 applications provide power
to external devices, it is designed to protect its host
device from malfunctions in those peripherals

8 4650.2001.10.0.93

AAT4650

5V/3V PC Card Power Switch

through slew rate control, current limiting, and ther­mal limiting. The AAT4650 current limit and thermal
limit serve as an immediate and reliable electronic
fuse without any increase in RDSfor this function.
Other solutions such as a poly fuse do not protect
the host power supply and system from mishandling,
or short circuited peripherals, they will only prevent a
fire. The AAT4650 high speed current limit and
thermal limit not only prevent fires, they also isolate
the power supply and entire system from any activi­ty at the external port, and report a mishap by means
of a FAULT signal.

Overcurrent and overtemperature go hand in hand.
Once an overcurrent condition exists, the current
supplied to the load by the AAT4650 is limited to the
overcurrent threshold. This results in a voltage drop
across the AAT4650 which causes excess power
dissipation and a package temperature increase. As
the die begins to heat up, the overtemperature circuit
is activated. If the temperature reaches the maxi­mum level, the AAT4650 automatically switches off
the P-channel MOSFETs. While they are off, the
overtemperature circuit remains active. Once the
temperature has cooled by approximately 10°C, the
P-channel MOSFETs are switched back on. In this
manner, the AAT4650 is thermally cycled on and off
until the short circuit is removed. Once the short is
removed, normal operation automatically resumes.

To save power, the full high speed overcurrent cir­cuit is not activated until a lower threshold of cur­rent (approximately 700mA) is exceeded in the
power device. When the load current exceeds this

crude threshold, the AAT4650 quiescent current
increases from 15µA to 150µA. The high speed
overcurrent circuit works by linearly limiting the cur­rent when the current limit is reached. As the volt­age begins to drop on Vcc due to current limiting,
the current limit magnitude varies, and generally
decreases as the Vcc voltage drops to 0 volts.

Switching Vcc Voltage

The AAT4650 meets PC card standards for switch­ing the Vcc output by providing a ground path for
Vcc as well as a hi impedance state. The PC card
protocol for determining low voltage operations is
to first power the peripheral with 5 volts and poll for

3.3 volt operation. When transitioning from 5 volts
to 3.3 volts, Vcc must be discharged to less than

0.8 volts to provide a hard reset. The resistive
ground state (CTL1=0, CTL0=0) will accommodate
this. The ground state will also guarantee the Vcc
voltage to be discharged within the specified
100ms amount of time.

Printed Circuit Board Layout
Recommendations

For proper thermal management, to minimize PCB
trace resistance, and to take advantage of the low
R
rules should be followed: Vcc3, Vcc5, and Vcc
should be routed using wider than normal traces, the
two Vcc pins (6 and 7) should be connected to the
same wide PCB trace, and GND should be connect­ed to a ground plane. For best performance, CINand
C

of the AAT4650, a few circuit board layout

DS(ON)

should be placed close to the package pins.

OUT

Typical PC Card Application Circuit

Power

Supply

PC Card

Controller

4650.2001.10.0.93 9

5V

3.3V

V

CC

FAULT

CTL1
CTL0

C

IN5

1µF

100KΩ

C

IN3

1µF

8

VCC5

5

V

3

CTL1

2

CTL0

4

FAULT

1

GND

CC

3

AAT4650

PC Card

6,7

V

CC

C

OUT

0.1µF

Slot

V

CC

Evaluation Board Layout

The AAT4650 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.

AAT4650

5V/3V PC Card Power Switch

Figure 2: Evaluation board Figure 3: Evaluation board Figure 4: Evaluation board
top side silk screen layout / component side layout solder side layout
assembly drawing

10 4650.2001.10.0.93

Ordering Information

AAT4650

5V/3V PC Card Power Switch

Package Marking

SO-8 AAT4650IAS-B1 AAT4650IAS-T1

TSSOP-8 AAT4650IHS-B1 AAT4650IHS-T1

Package Information

SOP-8

E

H

D

7(4x)

A

A2

b

y

A1

e

Q

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

c

L

Y 0.00 0.10 0.000 0.004

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.

4650.2001.10.0.93 11

TSSOP-8

AAT4650

5V/3V PC Card Power Switch

1 2

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

E

0.20

R1

AA2

R

1

θ2 12°

b

A1

DETAIL A

2

L

L1

Advanced Analogic Technologies, Inc.

1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086
Phone [phone]
Fax [phone]

12 4650.2001.10.0.93