LTC1470/LTC1471
Single and Dual
PCMCIA Protected
3.3V/5V V
CC
Switches
FEATURES
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DESCRIPTION
The LTC
®
1470 switches the V
CC
pins of a Personal Com-
puter Memory Card International Association (PCMCIA)
card slot between three operating states: OFF, 3.3V and
5V. Two low R
DS(ON)
N-channel power MOSFETs are
driven by a built-in charge pump which generates a
voltage higher than the supply voltage to fully enhance
each switch when selected by the input control logic.
The LTC1470 inputs are compatible with industry stan-
dard PCMCIA controllers. A built-in XOR ensures that both
switches are never on at the same time. This function also
makes the LTC1470 compatible with both active-low and
active-high controllers (see Applications Information sec-
tion). The switch rise times are controlled to eliminate
power supply glitching.
The LTC1470 features built-in SafeSlot
TM
current limit and
thermal shutdown. The output is limited to 1A during short
circuit to ground but 2A of peak operating current is
allowed.
The LTC1471 is a dual version of the LTC1470 and is
available in a 16-pin SO package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
SafeSlot is a trademark of Linear Technology Corporation.
Single 3.3V/5V Switch in 8-Pin SO Package
Dual 3.3V/5V Switch in 16-Pin SO Package
Built-In Current Limit and Thermal Shutdown
Built-In Charge Pumps (No 12V Required)
Extremely Low R
DS(ON)
MOSFET Switches
Output Current Capability: 1A
Inrush Current Limited (Drives 150µF Loads)
Quiescent Current in Standby: 1µA
No Parasitic Body Diodes
Built-In XOR Function Eliminates “Glue” Logic
Break-Before-Make Switching
Controlled Rise and Fall Times
APPLICATIONS
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Notebook Computers
Palmtop Computers
Pen-Based Computers
Handi-Terminals
PC Card Reader/Writers
3.3V/5V Power Supply Switch
TYPICAL APPLICATION
Dual Slot PCMCIA 3.3V/5V V
CC
Switch
5V
0.1µF
5V
IN
3V
IN
AOUT
LTC1471
AEN1
PCMCIA
CARD SLOT
CONTROLLER
AEN0
BEN1
(Hi-Z/3.3V/5V)
BOUT
BEN0
GND
V
CC
10k
1470/71 TA01
Linear Technology PCMCIA Product Family
DEVICE
DESCRIPTION
Single PCMCIA VPP Driver/Regulator
Dual PCMCIA VPP Driver/Regulator
Single PCMCIA Switch Matrix
Dual PCMCIA Switch Matrix
Single Protected V
CC
3.3V/5V Switch Matrix
Dual Protected V
CC
3.3V/5V Switch Matrix
Protected V
CC
and VPP Switch Matrix
PACKAGE
8-Pin SO
16-Pin SO*
14-Pin SO
24-Pin SSOP
8-Pin SO
16-Pin SO*
16-Pin SO*
3.3V
0.1µF
V
CC
(Hi-Z/3.3V/5V)
V
CC
10k
V
CC
PCMCIA
CARD SLOT
PCMCIA
CARD SLOT
LT
®
1312
LT1313
LTC1314
LTC1315
LTC1470
LTC1471
LTC1472
+
1µF
+
1µF
*Narrow Body
U
U
U
1
LTC1470/LTC1471
ABSOLUTE
MAXIMUM
RATINGS
3.3V Supply Voltage (Note 1) .................................. 7V
5V Supply Voltage (Note1) ....................................... 7V
Enable Input Voltage ........................ 7V to (GND – 0.3V)
Output Voltage (OFF) (Note 1) ......... 7V to (GND – 0.3V)
Output Short-Circuit Duration .......................... Indefinite
Operating Temperature ............................... 0°C to 70°C
Junction Temperature .......................................... 100°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
OUT 1
5V
IN
2
EN1 3
EN0 4
8
7
6
5
OUT
3V
IN
3V
IN
GND
LTC1470CS8
S8 PART MARKING
1470
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 100°C,
θ
JA
= 150°C/W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL
3V
IN
5V
IN
I
3VIN
PARAMETER
3.3V Supply Voltage Range
5V Supply Voltage Range
3.3V Supply Current
3V
IN
= 3.3V, 5V
IN
= 5V (Note 2), T
A
= 25°C, unless otherwise noted.
MIN
2.70
4.75
TYP
MAX
3.60
5.25
0.01
40
0.01
0.01
100
140
0.12
0.14
q
CONDITIONS
Program to Hi-Z (Note 3)
Program to 3.3V, No Load (Note 3)
Program to 5V, No Load (Note 3)
Program to Hi-Z (Note 3)
Program to 3.3V (Note 3)
Program to 5V (Note 3)
Program to 3.3V, I
OUT
= 500mA
Program to 5V, I
OUT
= 500mA
Program to Hi-Z, 0V
≤
V
OUT
≤
5V (Note 3)
Program to 3.3V, V
OUT
= 0V (Note 4)
Program to 5V, V
OUT
= 0V (Note 4)
I
5VIN
5V Supply Current
R
ON
I
LKG
I
LIM3V
I
LIM5V
V
ENH
V
ENL
I
EN
3.3V Switch ON Resistance
5V Switch ON Resistance
Output Leakage Current OFF
3.3V Current Limit
5V Current Limit
Enable Input High Voltage
Enable Input Low Voltage
Enable Input Current
0V
≤
V
EN
≤
5V
2
U
U
W
W W
U
W
TOP VIEW
AOUT 1
A5V
IN
2
AEN1 3
AEN0 4
GND 5
B3V
IN
6
B3V
IN
7
BOUT 8
16 AOUT
15 A3V
IN
14 A3V
IN
13 GND
12 BEN0
11 BEN1
10 B5V
IN
9
BOUT
ORDER PART
NUMBER
LTC1471CS
S PACKAGE
16-LEAD PLASTIC SO
T
JMAX
= 100°C,
θ
JA
= 100°C/W
UNITS
V
V
µA
µA
µA
µA
µA
µA
Ω
Ω
µA
A
A
V
q
q
q
q
q
q
10
80
10
10
160
200
0.16
0.18
±10
1
1
q
q
q
2.0
0.8
±1
V
µA
LTC1470/LTC1471
ELECTRICAL CHARACTERISTICS
SYMBOL
t
0
to t
3
t
3
to t
5
t
0
to t
5
PARAMETER
Delay and Rise Time (Note 5)
Delay and Rise Time (Note 5)
Delay and Rise Time (Note 5)
3V
IN
= 3.3V, 5V
IN
= 5V (Note 2), T
A
= 25°C, unless otherwise noted.
MIN
0.2
0.2
0.2
TYP
0.32
0.52
0.38
MAX
1.0
1.0
1.0
UNITS
ms
ms
ms
CONDITIONS
Transition from 0V to 3.3V, R
OUT
= 100Ω, C
OUT
= 1µF
Transition from 3.3V to 5V, R
OUT
= 100Ω, C
OUT
= 1µF
Transition from 0V to 5V, R
OUT
= 100Ω, C
OUT
= 1µF
The
q
denotes the specifications which apply over the full operating
temperature range.
Note 1:
For the LTC1470, the two output pins (1, 8) must be connected
together and the two 3.3V supply input pins (6 , 7) must be connected
together. For the LTC1471, the two AOUT pins (1, 16) must be connected
together, the two BOUT pins (8, 9) must be connected together, the two
A3V
IN
supply input pins (14, 15) must be connected together, the two
B3V
IN
supply pins (6, 7) must be connected together and the two GND
pins (5, 13) must be connected together.
Note 2:
Power for the input logic and charge pump circuitry is derived
from the 5V
IN
supply pin(s) which must be continuously powered.
Note 3:
Measured current is per channel with the other channel
programmed off for the LTC1471.
Note 4:
The output is protected with foldback current limit which reduces
the short-circuit (0V) currents below peak permissible current levels at
higher output voltages.
Note 5:
To 90% of final value.
TYPICAL PERFORMANCE CHARACTERISTICS
3V
IN
Supply Current (OFF)
5
4
3
2
1
0
–1
0
T
A
= 25°C
PROGRAMMED TO OFF
120
100
80
60
40
20
0
4
1470/71 G04
3V
IN
SUPPLY CURRENT (µA)
3V
IN
SUPPLY CURRENT (µA)
5V
IN
SUPPLY CURRENT (µA)
3
1
2
3V
IN
SUPPLY VOLTAGE (V)
5V
IN
Supply Current (3.3V ON)
300
250
200
150
100
50
0
T
A
= 25°C
PROGRAMMED
TO 3.3V, NO LOAD
3.3V SWITCH RESISTANCE (Ω)
5V
IN
SUPPLY CURRENT (µA)
5V
IN
SUPPLY CURRENT (µA)
0
1
2
3
4
5
5V
IN
SUPPLY VOLTAGE (V)
U W
6
1470/71 G03
(LTC1470 or 1/2 LTC1471)
5V
IN
Supply Current (OFF)
5
4
3
2
1
0
–1
T
A
= 25°C
PROGRAMMED TO OFF
3V
IN
Supply Current (3.3V ON)
T
A
= 25°C
PROGRAMMED TO
3.3V, NO LOAD
0
3
1
2
3V
IN
SUPPLY VOLTAGE (V)
4
1470/71 G05
0
1
2
3
4
5
5V
IN
SUPPLY VOLTAGE (V)
6
1470/71 G01
5V
IN
Supply Current (5V ON)
300
250
200
150
100
50
0
T
A
= 25°C
PROGRAMMED
TO 5V, NO LOAD
0.30
0.25
0.20
0.15
0.10
0.05
0
3.3V Switch Resistance
PROGRAMMED
TO 3.3V
0
1
5
2
3
4
5V
IN
SUPPLY VOLTAGE (V)
6
0
25
50
75
100
JUNCTION TEMPERATURE (°C)
125
1470/71 G07
1470/71 G02
3
LTC1470/LTC1471
TYPICAL PERFORMANCE CHARACTERISTICS
5V Switch Resistance
OUTPUT VOLTAGE (V) INRUSH CURRENT (A)
OUTPUT VOLTAGE (V) INRUSH CURRENT (A)
0.30
0.25
0.20
0.15
0.10
0.05
0
0
25
50
75
100
JUNCTION TEMPERATURE (°C)
125
1470/71 G06
PROGRAMMED
TO 5V
5V SWITCH RESISTANCE (Ω)
PIN FUNCTIONS
LTC1470
OUT (Pins 1, 8):
Output Pins. The outputs of the LTC1470
are switched between three operating states: OFF, 3.3V
and 5V. These pins are protected against accidental short
circuits to ground by SafeSlot current limit circuitry which
protects the socket, the card, and the system power
supplies against damage. A second level of protection is
provided by thermal shutdown circuitry which protects
both switches against over-temperature conditions.
5V
IN
(Pin 2):
5V Input Supply Pin. The 5V
IN
supply pin
serves two purposes. The first purpose is as the power
supply input for the 5V NMOS switch. The second purpose
is to provide power for the input, gate drive, and protection
circuitry for both the 3.3V and 5V V
CC
switches. This pin
must therefore be continuously powered.
EN1, EN0 (Pins 3, 4):
Enable Inputs. The two V
CC
Enable
inputs are designed to interface directly with industry
standard PCMCIA controllers and are high impedance
CMOS gates with ESD protection diodes to ground, and
should not be forced below ground. Both inputs have
about 100mV of built-in hysteresis to ensure clean switch-
ing between operating modes. The LTC1470 is designed
to operate
without
12V power. The gates of the V
CC
NMOS
switches are powered by charge pumps from the 5V
IN
supply pins (see Applications Information section for
more detail). The Enable inputs should be turned off (both
asserted high or both asserted low) at least 100µs before
the 5V
IN
power is removed to ensure that both V
CC
NMOS
switch gates are fully discharged and both switches are in
the high impedance mode.
GND (Pin 5):
Ground Connection.
3V
IN
(Pins 6, 7):
3V Input Supply Pins. The 3V
IN
supply
pins serve as the power supply input for the 3.3V switches.
These pins do not provide any power to the internal control
circuitry and therefore do not consume any power when
unloaded or turned off.
4
U W
(LTC1470 or 1/2 LTC1471)
Inrush Current (5V Switch)
3
2
1
0
C
OUT
= 150µF
R
OUT
= 10Ω
6
4
2
0
– 0.2
0
0.2
0.4 0.6 0.8
TIME (ms)
1.0
1.2 1.4
1470/71 G08
Inrush Current (3.3V Switch)
3
2
1
0
C
OUT
= 15µF
R
OUT
= 6.6Ω
6
4
2
0
– 0.2
0
0.2
C
OUT
= 150µF
R
OUT
= 6.6Ω
0.4 0.6 0.8
TIME (ms)
1.0
1.2 1.4
1470/71 G09
T
J
= 25°C
C
OUT
= 150µF
R
OUT
= 6.6Ω
CURRENT
LIMITED
T
J
= 25°C
C
OUT
= 15µF
R
OUT
= 10Ω
U
U
U
LTC1470/LTC1471
PIN FUNCTIONS
LTC1471
AOUT, BOUT(Pins 1, 16, 8, 9):
Output Pins. The outputs
of the LTC1471 are switched between three operating
states: OFF, 3.3V and 5V. These pins are protected against
accidental short circuits to ground by SafeSlot current
limit circuitry which protects the socket, the card, and the
system power supplies against damage. A second level of
protection is provided by thermal shutdown circuitry.
5V
IN
(Pins 2, 10):
5V Input Supply Pins. The 5V
IN
supply
pins serve two purposes. The first purpose is as the power
supply input for the 5V NMOS switches. The second
purpose is to provide power for the input, gate drive, and
protection circuitry. These pins must therefore be con-
tinuously powered.
EN1, EN0 (Pins 3, 4, 11, 12):
Enable Inputs. The enable
inputs are designed to interface directly with industry
standard PCMCIA controllers and are high impedance
CMOS gates with ESD protection diodes to ground, and
should not be forced below ground. All four inputs have
about 100mV of built-in hysteresis to ensure clean switch-
ing between operating modes. The LTC1471 is designed
to operate
without
12V power. The gates of the V
CC
NMOS
switches are powered by charge pumps from the 5V
IN
supply pins (see Applications Information section for
more detail). The enable inputs should be turned off at
least 100µs before the 5V
IN
power is removed to ensure
that all NMOS switch gates are fully discharged and are in
the high impedance mode.
GND (Pins 5, 13):
Ground Connections.
3V
IN
(Pins 6, 7, 14, 15):
3V Input Supply Pins. The 3V
IN
supply pins serve as the power supply input for the 3.3V
switches. These pins do not not provide any power to the
internal control circuitry, and therefore, do not consume
any power when unloaded or turned off.
BLOCK DIAGRAM
EN0
TTL-TO-CMOS
CONVERTER
EN1
TTL-TO-CMOS
CONVERTER
W
U
U
U
(LTC1470 or 1/2 LTC1471)
5V
IN
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
0.14Ω
BREAK-BEFORE-
MAKE SWITCH
AND CONTROL
OSCILLATOR
AND BIAS
CHARGE
PUMP
CURRENT LIMIT
AND THERMAL
SHUTDOWN
OUTPUT
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
0.12Ω
3V
IN
LTC1470-BD01
5
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