SmartSwitch
TM
AAT4651
5V/3V PC Card Power Switch
4651.2005.06.1.1
1
General Description
The AAT4651 SmartSwitchTM 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 cir-
cuitry from whichever input voltage is higher. The
device's output, V
CC
, is slew rate controlled and cur-
rent limited, in compliance with PC card specifica-
tions. The current limit response time to a short cir-
cuit is typically 1s. The internal P-channel MOS-
FET 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
three states for V
CC
are V
CC5
, V
CC3
, or ground.
When in the ground state, V
CC
is pulled to ground by
an 200
resistor. An open drain FAULT output is
asserted during over-current conditions. During
power-up slewing, FAULT also signals that V
CC
is
out of tolerance. An internal over-temperature sen-
sor forces V
CC
to a high impedance state when an
over-temperature condition exists. Quiescent cur-
rent is typically a low 15A, as long as I
CC
is less
than approximately 500mA. Above this load current,
the quiescent current increases to 200A.
The AAT4651 is available in a Pb-free, 8-pin SOP
or TSSOP package and is specified over the -40C
to +85C temperature range.
Features
2.7V to 5.5V Input Voltage Range
80m
(5V) Typical R
DS(ON)
Low Quiescent Current: 15A (Typ)
Reverse-Blocking Switches
Short-Circuit Protection
Over-Temperature Protection
FAULT Flag Output
Temperature Range: -40C to +85C
8-Pin SOP or TSSOP Package
Applications
Notebook Computer
PDA, Subnotebook
Power Supply Multiplexer Circuit
Typical Application
C
OUT
0.1
F
VCC5
C
IN5
1
F
C
IN3
1
F
VCC3
VCCD1
VCCD0
FAULT
VCC
GND
AAT4651
8
5
2
3
4
1
6,7
VCC3
VCC5
GND
GND
VCC
VCCD1
VCCD0
FAULT
Pin Descriptions
Pin Configuration
SOP-8
TSSOP-8
(Top View)
(Top View)
Control Logic Table
VCCD1
VCCD0
Function
Result
0
0
OFF
80
V
CC
to GND
0
1
3.3V
V
CC
= V
CC3
1
0
5V
V
CC
= V
CC5
1
1
OFF
80
V
CC
to GND
GND
VCCD1
VCCD0
FAULT
VCC5
VCC
VCC
VCC3
4
3
2
1
5
6
7
8
1
2
VCC
VCC5
VCC
VCC3
GND
VCCD1
VCCD0
FAULT
1
2
3
4
8
7
6
5
Pin #
Symbol
Function
1
GND
Ground connection.
2
VCCD1
Control input (see Control Logic Table below).
3
VCCD0
Control input (see Control Logic Table below).
4
FAULT
Open drain output; signals over-current condition.
5
VCC3
3V supply.
6
VCC
Output (see Control Logic Table below).
7
VCC
Output (see Control Logic Table below).
8
VCC5
5V supply.
AAT4651
5V/3V PC Card Power Switch
2
4651.2005.06.1.1
Absolute Maximum Ratings
1
T
A
= 25C, unless otherwise noted.
Thermal Characteristics
3
Symbol
Description
Value
Units
JA
Thermal Resistance (SOP-8)
120
C/W
Thermal Resistance (TSSOP-8)
150
P
D
Power Dissipation (SOP-8)
1.0
W
Power Dissipation (TSSOP-8)
833
mW
Symbol
Description
Value
Units
V
CC3
, V
CC5
IN to GND
-0.3 to 6
V
V
CC
OUT to GND
-0.3 to 6
V
I
MAX
Maximum Continuous Switch Current
Current Limited
A
T
J
Operating Junction Temperature Range
-40 to 150
C
V
ESD
ESD Rating
2
-- HBM
4000
V
AAT4651
5V/3V PC Card Power Switch
4651.2005.06.1.1
3
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi-
tions 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 1.5k
resistor into each pin.
3. Mounted on an FR4 board.
Electrical Characteristics
V
CC5
= 5.0V, V
CC3
= 3.3V, T
A
= -40C to +85C, unless otherwise noted. Typical values are at T
A
= 25C; bold
values designate full temperature range.
Symbol
Description
Conditions
Min Typ Max Units
V
CC
Output
Iccsc
Short-Circuit Current Limit
V
CC
= V
CCIN
-0.5V, On Mode V
CC3
1.0
2.5
A
or V
CC5
Selected, T
A
= 25C
V
CC
= 3.0V, T
A
= 25C
85
110
m
R
DS(ON)
On-Resistance
V
CC
= 5.0V, T
A
= 25C
80
100
m
R
CLAMP
Clamp Resistance
V
CC
= Clamped to GND,
80
200
I
CCOUT
= 10mA Sinking
Tcrds
Switch Resistance
2800
ppm/C
Temperature Coefficient
V
CC
Switching Time (Refer to Figure 1)
t1
Output Turn-On Delay Time
V
CC
= 0V to 10% of 3.3V, R
OUT
= 10
500
2000
s
t2
Output Turn-On Delay Time
V
CC
= 0V to 10% of 5.0V, R
OUT
= 10
500
1500
s
t3
Output Rise Time
V
CC
= 10% to 90% of 3.3V, R
LOAD
= 10
300
1000 3000
s
t4
Output Rise Time
V
CC
= 10% to 90% of 5.0V, R
LOAD
= 10
300
1000 3000
s
t5
Output Turn-Off Delay Time
V
CC
= 3.3V to 90% of 3.3V, R
LOAD
= 10
400
s
t6
Output Turn-Off Delay Time
V
CC
= 5.0V to 90% of 5.0V, R
LOAD
= 10
400
s
t7
Output Fall Time to Off State
V
CC
= 90% to 10% of 3.3V, R
LOAD
= 10
200
s
t8
Output Fall Time to Off State
V
CC
= 90% to 10% of 5.0V, R
LOAD
= 10
200
s
Power Supply
V
CC3
V
CC3
Operation Voltage
2.7
5.5
V
V
CC5
V
CC5
Operation Voltage
2.7
5.5
V
V
CC
= 5V or Off, V
CC3
< V
CC5
,
1
I
CC3
V
CC3
Supply Current
I
CC
Out = 0
A
V
CC
= 3.3V, V
CC3
< V
CC5
, I
CC
Out = 0
5
20
I
CC5
V
CC5
Supply Current
V
CC
= Off, V
CC5
> V
CC3
, I
CC
Out = 0
1
V
CC
= 3.3V, V
CC5
> V
CC3
, I
CC
Out = 0
10
40
A
V
CC
= 5V, V
CC5
> V
CC3
, I
CC
Out = 0
15
40
Parallel Interface
VCCD LOW VCCD Input Low Voltage
V
CC3
or V
CC5
= 3.0V to 5.5V
1
0.8
V
VCCD HI
VCCD Input High Voltage
V
CC3
or V
CC5
= 2.7V to 3.6V
2.0
V
V
CC3
or V
CC5
= 4.5V to 5.5V
2.4
I
SINK VCCD
VCCD Input leakage
V
CTL
= 5.5V
0.01
1
A
V
FAULTLOW
FAULT Logic Output Low
I
SINK
= 1mA
0.4
V
Voltage
I
SINKFAULT
FAULT Logic Output High
V
FAULT
= 5.5V
0.05
1
A
Leakage Current
Other
OTMP
Over-Temperature Shutdown
125
C
AAT4651
5V/3V PC Card Power Switch
4
4651.2005.06.1.1
1. For VCCD outside this range, consult Typical VCCD Threshold curve.
Typical Characteristics
Unless otherwise noted, T
A
= 25C.
R
DS(ON)
vs. Temperature
60.0
70.0
80.0
90.0
100.0
110.0
120.0
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
R
DS(ON)
(m
)
V
CC
= V
CC3
= 3.0V
V
CC
= V
CC5
= 5.0V
Off-Switch Current vs. Temperature
(I
CC5
)
0.0000
0.0001
0.0010
0.0100
0.1000
1.0000
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
V
CC5
= 5V
V
CC3
= 3V
VCCD1 = 0V
VCCD0 = 0V
Off-Switch Current (
A)
Off-Switch Current vs. Temperature
(I
CC3
)
0.0000
0.0001
0.0010
0.0100
0.1000
1.0000
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
V
CC3
= 3V
V
CC5
= 5V
VCCD1 = 0V
VCCD0 = 0V
Off-Switch Current (
A)
Current Limit
(V
CC
= V
CC5
)
0
0.5
1
1.5
2
0
1
2
3
4
5
6
Output Voltage (V)
Current Limit
(V
CC
= V
CC3
)
0
0.5
1
1.5
2
0
0.5
1
1.5
2
2.5
3
Output Voltage (V)
Quiescent Current vs. Temperature
(I
CC5
)
0
5
10
15
20
25
30
-40
-20
0
20
40
60
80
100
120
Temperature (
C)
V
CC3
= 3V
V
CC5
= 5V
VCCD1
VCCD0 = 0V
= 5V
Quiescent Current (
A)
AAT4651
5V/3V PC Card Power Switch
4651.2005.06.1.1
5
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