LINER LTC1472CS

LTC1472
Protected PCMCIA VCC and
VPP Switching Matrix
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FEATURES
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DESCRIPTIO
Both VCC and VPP Switching in a Single Package
Built-In Current Limit and Thermal Shutdown
16-Pin (Narrow) SOIC Package
Inrush Current Limited (Drives 150µF Loads)
Continuous 12V Power Not Required
Extremely Low RDS(ON) NMOS Switches
Guaranteed 1A VCC Current and 120mA VPP Current
1µA Quiescent Current in Standby
No External Components Required
Compatible with Industry Standard Controllers
Break-Before-Make Switching
Controlled Rise and Fall Times
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APPLICATIO S
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The LTC®1472 switching matrix routes power to both the
VCC and VPP power supply pins of the PCMCIA compatible
card socket. The VCC output of the LTC1472 is switched
between three operating states: OFF, 3.3V, and 5V. The
VPP output is switched between four operating states: 0V,
VCC, 12V, and Hi-Z. The output voltages are selected by
two sets of digital inputs which are compatible with
industry standard PC Card controllers (see Truth Tables).
The VCC output of the LTC1472 can supply up to 1A of
current and the VPP output up to 120mA. Both switches
have built-in SafeSlotTM current limiting and thermal shutdown to protect the card, socket and power supply against
accidental short-circuit conditions.
The LTC1472 is designed to conserve power by automatically dropping to 1µA standby current when the two
outputs are switched OFF. A shutdown pin is provided
which holds the external 12V regulator in standby mode
except when required for VPP power.
OpenCable Set Top Box
Notebook Computers
Palmtop Computers
Pen-Based Computers
Bar-Code Readers
The LTC1472 is available in 16-pin SO package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
SafeSlot is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
Linear Technology PCMCIA Product Family
Protected PCMCIA VCC and VPP Card Driver
12V
3.3V
3VIN
SHDN
0.1µF
VPPOUT
LTC1472
PACKAGE
LT 1312
Single PCMCIA VPP Driver/Regulator
8-Pin SO
LT1313
Dual PCMCIA VPP Driver/Regulator
16-Pin SO*
VPP1
LTC1314
Single PCMCIA Switch Matrix
14-Pin SO
VPP2
LTC1315
Dual PCMCIA Switch Matrix
24-Pin SSOP
PCMCIA
CARD SLOT
LTC1470
Protected VCC 5V/3.3V Switch Matrix
8-Pin SO
VCC
LTC1471
Dual Protected VCC 5V/3.3V Switch Matrix
16-Pin SO*
VCC
LTC1472
Protected VCC and VPP Switch Matrix
16-Pin SO*
®
TO 12V REGULATOR
OV, VCC, 12V, Hi-Z
0.1µF
VDD
VPP EN0
PCMCIA
CARD SLOT
CONTROLLER
DESCRIPTION
VPPIN
5VIN
5V
DEVICE
0.1µF
0.1µF
VPP EN1
VCC(IN)
VCC EN0
VCC(OUT)
VCC EN1
GND
OFF, 3.3V, 5V
+
10k
1µF
LTC1472-TA01
*Narrow Body
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LTC1472
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5VIN Supply Voltage ................................... – 0.3V to 7V
3VIN Supply Voltage ....................................– 0.3V to 7V
VPPIN Supply Voltage .............................– 0.3V to 13.2V
VCC(IN) Supply Voltage ................................... – 0.3 to 7V
VDD(IN) Supply Voltage ................................– 0.3V to 7V
VPPOUT (OFF) .........................................– 0.3V to 13.2V
VCC(OUT) (OFF) .............................................– 0.3V to 7V
Enable Inputs ............................................ – 0.3V to 5VIN
VPPOUT Short-Circuit Duration ........................ Indefinite
VCC(OUT) Short-Circuit Duration ....................... Indefinite
Operating Temperature Range ..................... 0°C to 70°C
Junction Temperature ........................................... 100°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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(Note 1)
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ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
VCC(OUT) 1
16 VCC(OUT)
5VIN 2
15 3VIN
VCC EN1 3
14 3VIN
VCC EN0 4
13 GND
VPPIN 5
12 VCC(IN)
SHDN 6
11 VPPOUT
VPP EN0 7
10 GND
VPP EN1 8
9
LTC1472CS
VDD
S PACKAGE
16-LEAD PLASTIC SO
TJMAX = 100°C, θJA = 100°C/W
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
(VCC Switch Section) The ● denotes specifications which apply over the full operating temperature range, otherwise specifications
are at TA = 25°C. 5VIN = 5V, 3VIN = 3.3V, VPP EN0 = VPP EN1 = OV, (Note 2) unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
MAX
UNITS
5VIN
5VIN Supply Voltage Range
(Note 3)
4.75
TYP
5.25
V
3VIN
3VIN Supply Voltage Range
(Note 4)
0
3.60
V
I5VIN
5VIN Supply Current
Program to Hi-Z
Program to 5V, No Load
Program to 3.3V, No Load
●
●
●
0.01
140
100
10
200
160
µA
µA
µA
I3VIN
3VIN Supply Current
Program to Hi-Z.
Program to 5V, No Load
Program to 3.3V, No Load
●
●
●
0.01
0.01
40
10
10
80
µA
µA
µA
RON
5V Switch On Resistance
3.3V Switch On Resistance
Program to 5V, IOUT = 500mA
Program to 3.3V, IOUT = 500mA
0.14
0.12
0.18
0.16
Ω
Ω
ILKG
Output Leakage Current OFF
VCC EN0 = VCC EN1 = 0V or 5V, 0V ≤ VCC(OUT) ≤ 5V
±10
µA
ILIM5V
VCC(OUT) 5V Current Limit
Program to 5V, VCC(OUT) = 0V (Note 5)
ILIM3V
VCC(OUT) 3.3V Current Limit
Program to 3.3V, VCC(OUT) = 0V (Note 5)
VCCENH
VCC Enable Input High Voltage
●
VCCENL
VCC Enable Input Low Voltage
●
IVCCEN
VCC Enable Input Current
0V ≤ VCCEN ≤ 5V
±1
µA
tVCC1
Delay + Rise Time
From 0V to 3.3V, RLOAD = 100Ω, CLOAD = 1µF (Note 6)
0.2
0.32
1
ms
tVCC2
Delay + Rise Time
From 3.3V to 5V, RLOAD = 100Ω, CLOAD = 1µF (Note 6)
0.2
0.52
1
ms
tVCC3
Delay + Rise Time
From 0V to 5V, RLOAD = 100Ω, CLOAD = 1µF (Note 6)
0.2
0.38
1
ms
●
1
A
1
A
2
V
0.8
V
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LTC1472
ELECTRICAL CHARACTERISTICS
(VPP Switch Section) The ● denotes specifications which apply over the full operating temperature range, otherwise specifications
are at TA = 25°C. VDD = 5V, VCC(IN) = 5V, VPPIN = 12V, VCCEN0 = VCCEN1 = 0V, (Note 2) unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
VCC(IN)
VCC Input Voltage Range
MAX
UNITS
3
5.5
V
VPPIN
VPP Input Voltage Range
(Note 7)
VDD
Logic Supply Voltage Range
(Note 8)
●
0
12.6
V
●
4.5
5.5
V
ICCIN
VCC(IN) Supply Current, No Load
Program to VPPIN or VCC(IN) VPPIN = 12V
Program to 0V or Hi-Z
●
●
35
0.01
60
10
µA
µA
IPPIN
VPPIN Supply Current, No Load
Program to VPPIN or VCC(IN)
Program to 0V or Hi-Z
●
●
40
0.01
80
10
µA
µA
IDD
VDD Supply Current, No Load
Program to VPPIN
Program to VCC(IN), VPPIN = 0V
Program to VCC(IN), VPPIN = 12V
Program to 0V or Hi-Z
●
●
●
●
70
85
40
0.01
120
150
80
10
µA
µA
µA
µA
IVPPOUT
Hi-Z Output Leakage Current
Program to Hi-Z, 0V < VPPOUT < 12V
●
0.01
10
µA
RON
On Resistance VPPOUT to VPPIN
On Resistance VPPOUT to VCC(IN)
On Resistance VPPOUT to GND
VPPIN = 12V, ILOAD = 120mA
VCC(IN) = 5V, ILOAD = 5mA
VDD = 5V, ISINK = 1mA
0.50
1.70
100
1
5
250
Ω
Ω
Ω
VPPENH
VPP Enable Input High Voltage
VDD = 5V
●
VPPENL
VPP Enable Input Low Voltage
VDD = 5V
●
0.8
V
IVPPEN
VPP Enable Input Current
0V < VPP EN < VDD
●
±1
µA
VSDH
SHDN Output High Voltage
Program to 0V, VCC(IN) or Hi-Z, ILOAD = 400µA
●
VSDL
SHDN Output Low Voltage
Program to VPPIN, ISINK = 400µA
●
0.4
V
ILIMVCC
VPPOUT Current Limit, VCC(IN)
Program to VCC(IN), VPPOUT = 0V (Note 5)
ILIMVPP
VPPOUT Current Limit, VPPIN
Program to VPPIN, VPPOUT = 0V (Note 5)
tVPP1
Delay and Rise Time
From 0V to VCC(IN),VPPIN = 0V (Note 9)
5
15
50
µs
tVPP2
Delay and Rise Time
From 0V to VPPIN (Note 9)
25
85
250
µs
tVPP3
Delay and Rise Time
From VCC(IN) to VPPIN (Note 9)
30
100
300
µs
tVPP4
Delay and Fall Time
From VPPIN to VCC(IN) (Note 10)
5
15
50
µs
tVPP5
Delay and Fall Time
From VPPIN to 0V (Note 11)
10
35
100
µs
tVPP6
Delay and Fall Time
From VCC(IN) to 0V, VPPIN = 0V (Note 11)
10
30
100
µs
tVPP7
Output Turn-On Delay
From Hi-Z to VCC(IN) (Note 9)
5
15
50
µs
tVPP8
Output Turn-On Delay
From Hi-Z to VPPIN (Note 9)
25
85
250
µs
●
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: VENH = 5V, VENL = 0V. See VCC and VPP Switch Truth Tables for
programming enable inputs for desired output states.
Note 3: Power for the VCC input logic and charge pump circuitry is derived
from the 5VIN power supply which must be continuously powered. 12V
and 3.3V power is not required to control the NMOS VCC switches. (See
Applications Information.)
Note 4: The two 3VIN supply input pins (14 and 15) must be connected
together and the two VCC(OUT) output pins (1 and 16) must be connected
together. The 3VIN supply pins do not need to be continuously powered
and may drop to 0V when not required.
Note 5: The VCC and VPP output are protected with foldback current limit
which reduces the short-circuit (0V) currents below peak permissible
current levels at higher output voltages.
TYP
2
V
3.5
V
60
mA
100
mA
Note 6: To 90% of final value.
Note 7: 12V power is only required when VPPOUT is programmed to 12V.
The external 12V regulator can be shutdown at all other times. Built-in
charge pumps power the internal NMOS switches from the 5V VDD supply
when 12V is not present.
Note 8: Power for the VPP input logic and charge pump circuitry is derived
from the VDD power supply which must be continuously powered.
Note 9: To 90% of the final value, COUT = 0.1µF, ROUT = 2.9k.
Note 10: To 10% of the final value, COUT = 0.1µF, ROUT = 2.9k.
Note 11: To 50% of the initial value, COUT = 0.1µF, ROUT = 2.9k.
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LTC1472
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TYPICAL PERFORMANCE CHARACTERISTICS
5VIN Supply Current (5V ON)
5VIN Supply Current (OFF)
2
1
250
5VIN SUPPLY CURRENT (µA)
3
300
TA = 25°C VCC(OUT)
PROGRAMMED
TO 5V, NO LOAD
200
150
100
50
0
0
1
5
2
3
4
5VIN SUPPLY VOLTAGE (V)
6
0
1
5
2
3
4
5VIN SUPPLY VOLTAGE (V)
3
2
1
TA = 25°C VCC(OUT)
PROGRAMMED TO
3.3V, NO LOAD
80
60
40
0.20
0.15
0.10
0
4
OUTPUT VOLTAGE (V) INRUSH CURRENT (A)
0.10
0.05
0
25
50
75
100
JUNCTION TEMPERATURE (°C)
125
LT1472 TPC07
25
50
75
100
JUNCTION TEMPERATURE (°C)
Inrush Current (3.3V Switch)
3
2
TJ = 25°C
CURRENT
LIMITED
1
0
6
COUT = 150µF
ROUT = 10Ω
COUT = 15µF
ROUT = 10Ω
4
2
0
– 0.2
0
0.2
0.4 0.6 0.8
TIME (ms)
125
LT1472 TPC06
Inrush Current (5V Switch)
0.15
0
0.25
LTC1472 TPC05
LTC1472 TPC04
0.20
VCC(OUT)
PROGRAMMED
TO 5V
0
3
1
2
3VIN SUPPLY VOLTAGE (V)
0
3.3V Switch Resistance
6
0.05
0
4
VCC(OUT)
PROGRAMMED
TO 3.3V
5
2
3
4
5VIN SUPPLY VOLTAGE (V)
5V Switch Resistance
20
0.30
1
0.30
100
0
3
1
2
3VIN SUPPLY VOLTAGE (V)
0
LTC1472 TPC03
5V SWITCH RESISTANCE (Ω)
3VIN SUPPLY CURRENT (µA)
3VIN SUPPLY CURRENT (µA)
0
6
120
TA = 25°C OUTPUT
PROGRAMMED TO OFF
0.25
100
3VIN Supply Current (3.3V ON)
5
0
150
LTC1472 TPC02
3VIN Supply Current (OFF)
–1
200
50
LTC1472 TPC01
4
TA = 25°C VCC(OUT)
PROGRAMMED
TO 3.3V, NO LOAD
250
1.0
1.2 1.4
LTC1472 TPC08
OUTPUT VOLTAGE (V) INRUSH CURRENT (A)
4
5VIN SUPPLY CURRENT (µA)
5VIN SUPPLY CURRENT (µA)
TA = 25°C VCC(OUT)
PROGRAMMED TO OFF
0
3.3V SWITCH RESISTANCE (Ω)
5VIN Supply Current (3.3V ON)
300
5
–1
(VCC Section) VPP EN0 = VPP EN1 = 0V
3
TJ = 25°C
2
COUT = 150µF
ROUT = 6.6Ω
1
0
6
COUT = 15µF
ROUT = 6.6Ω
4
COUT = 150µF
ROUT = 6.6Ω
2
0
– 0.2
0
0.2
0.4 0.6 0.8
TIME (ms)
1.0
1.2 1.4
LTC1472 TPC09
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LTC1472
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TYPICAL PERFORMANCE CHARACTERISTICS (VPP Section) VCC EN0 = VCC EN1 = 0V
VCC(IN) Supply Current (No Load)
VPPIN Supply Current (OFF)
100
60
VPPOUT PROGRAMMED
TO VPPIN OR VCC(IN)
40
20
0
VPPOUT PROGRAMMED
TO 0V OR Hi-Z
4
3
2
1
0
–1
2
3
4
5
VCC(IN) SUPPLY VOLTAGE (V)
2
8
6
10
4
VPPIN SUPPLY VOLTAGE
100
80
VPPOUT PROGRAMMED
TO VPPIN
60
40
VPPOUT PROGRAMMED
TO VCC(IN)
20
12
14
0
8
6
10
4
VPPIN SUPPLY VOLTAGE
2
LTC1472 TPC11
LTC1472 TPC10
VDD Supply Current (OFF)
12
14
LTC1472 TPC12
VDD Supply Current (No Load)
120
5
TA = 25°C
VPPOUT PROGRAMMED
TO 0V OR Hi-Z
TA = 25°C
VPPOUT PROGRAMMED
TO VPPIN, NO LOAD
100
VDD SUPPLY CURRENT (µA)
4
3
2
1
80
60
40
20
0
–1
TA = 25°C
VPPIN = 12V
NO LOAD
0
0
6
0
0
1
5
2
3
4
VDD SUPPLY VOLTAGE (V)
6
0
1
5
2
3
4
VDD SUPPLY VOLTAGE (V)
VDD Supply Current (ON)
Switch Resistances
120
10
TA = 25°C
VPPOUT PROGRAMMED
TO VPPIN, NO LOAD
100
80
VPPIN = 0V
60
6
LTC1472 TPC14
LTC1472 TPC13
SWITCH RESISTANCE (Ω)
1
VDD SUPPLY CURRENT (µA)
0
TA = 25°C
VPPOUT PROGRAMMED
TO 0V OR Hi-Z
VPPIN SUPPLY CURRENT (µA)
VPPIN SUPPLY CURRENT (µA)
80
VDD SUPPLY CURRENT (µA)
VCC(IN) SUPPLY CURRENT (µA)
TA = 25°C
–20
VPPIN Supply Current (No Load)
120
5
40
VPPIN = 12V
VCCIN TO VPPOUT
1
VPPIN TO VPPOUT
20
0
0
1
5
2
3
4
VDD SUPPLY VOLTAGE (V)
6
LTC1472 TPC15
0.1
0
20
40
60
TEMPERATURE (°C)
80
100
LTC1472 TPC16
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LTC1472
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PIN FUNCTIONS
Enable Input (Pins 3,4,7,8)
VCC(IN) Supply (Pin 12)
The two VCC and two VPP Enable inputs are designed to
interface directly with industry standard PCMCIA controllers. They are high impedance CMOS gates with ESD
protection diodes to ground, and should not be forced
above 5VIN or below ground. Both sets of inputs have
about 100mV of built-in hysteresis to ensure clean switching between operating modes.
The VCC(IN) supply pin is typically connected directly to the
VCC(OUT) pin from the VCC switch section of the LTC1472.
It can also be connected directly to a 3.3V or 5V power
supply if desired. This supply pin does not provide any
power to the internal control circuitry and is simply the
input to the VCC(IN)-VPPOUT switch and therefore does not
consume any power when unloaded or turned off.
Shutdown Output (Pin 6)
5VIN Supply (Pin 2)
The LTC1472 is designed to operate without continuous
12V power. The gates of the VCC NMOS switches are
powered by charge pumps from the 5VIN supply, and the
gates of the VPP NMOS switches are powered by charge
pumps powered from the VDD supply when 12V is not
present at the VPPIN pin (see Application Information for
more details). Therefore, the external 12V regulator can be
shut down most of the time, and only turned on when
programming the socket VPP pin to 12V.
The 5VIN 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 VCC
switches, this pin must be continuously powered.
The shutdown output is active high; i.e. the system 12V
regulator is shut down when this output is held high and
turned on when this output is held low.
VPPIN Supply (Pin 5)
The VPPIN supply pin serves two purposes. The first
purpose is to provide power and gate drive for the VPPINVPPOUT switch. The second purpose is to provide optional
12V gate drive for the VCC(IN)-VPPOUT switch. If, however,
this 12V power is not available, gate drive is obtained
automatically from the 5V VDD supply by an internal 5V to
12V charge pump converter.
VDD Supply (Pin 9)
The VDD pin provides power for the input, charge pump
and control circuitry for the VPP section of the LTC1472
and therefore must be continuously powered. The standby
quiescent current is typically 0.1µA when the VPPOUT pin
is programmed to 0V or Hi-Z and only rises to micropower
levels when the VPP switches are active.
The enable inputs should be turned off (both asserted high
or both asserted low) at least 100µs before the 5VIN power
is removed to ensure that both VCC NMOS switch gates are
fully discharged and both switches are in the high impedance mode.
3VIN Supply (Pins 14,15)
The 3VIN supply pin serves as the power supply input for
the 3.3V switch. This pin does not provide any power to the
internal control circuitry and therefore does not consume
any power when unloaded or turned off.
VCC(OUT) and VPPOUT Output (Pins 1,11,16)
The VCC output of the LTC1472 is switched between the
three operating states: OFF, 3.3V, and 5V. The VPP output
is switched between four operating states: 0, VCC, 12V and
Hi-Z. Both pins are protected against accidental shortcircuit conditions to ground by independent SafeSlot
foldback current-limit circuitry which protects the socket,
card and the system power supplies against damage. A
second level of protection is provided by independent
thermal shut down circuitry which protects each switch
against overtemperature conditions.
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LTC1472
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BLOCK DIAGRAM
5VIN
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
VCC EN0
VCC EN1
TTL-TO-CMOS
CONVERTER
BREAK-BEFOREMAKE SWITCH
AND CONTROL
OSCILLATOR
AND BIAS
TTL-TO-CMOS
CONVERTER
CHARGE
PUMP
0.14Ω
CURRENT LIMIT
AND THERMAL
SHUTDOWN
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
VCC(OUT)
0.12Ω
3VIN
VDD
VPPIN
SHDN
VPP EN0
TTL-TO-CMOS
CONVERTER
BREAK-BEFOREMAKE SWITCH
VPP EN1
TTL-TO-CMOS
CONVERTER
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
OSCILLATOR
AND BIAS
CHARGE
PUMP
0.5Ω
CURRENT LIMIT
AND THERMAL
SHUTDOWN
VCC(IN)
VPPIN
+
10V
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CHARGE
PUMP
1.7Ω
–
VPPOUT
100Ω
LTC1470-BD01
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OPERATION
The LTC1472 protected switch matrix is designed to be a
complete single slot solution for VCC and VPP switching in
a PCMCIA compatible card system. The LTC1472 consists
of two independent functional sections: the VCC switching
section, and the VPP switching section.
THE VCC SWITCHING SECTION
The VCC switching section of the LTC1472 consist of the
following functional blocks:
VCC Switch Input TTL-CMOS Converters
The LTC1472 VCC inputs are designed to accommodate a
wide range of 3V and 5V logic families. The input threshold
voltage is approximately 1.4V with approximately 100mV
of hysteresis. The inputs enable the bias generator, the
gate charge pumps and the protection circuity which are
powered from the 5VIN supply. Therefore, when the inputs
are turned off, the entire circuit is powered down and the
5VIN supply current drops below 1µA.
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LTC1472
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OPERATION
VCC XOR Input Circuitry
The LTC1472 ensures that the 3.3V and 5V switches are
never turned on at the same time by employing an XOR
function which locks out the 3.3V switch when the 5V
switch is turned on, and locks out the 5V switch when the
3.3V switch is turned on. This XOR function also makes it
possible for the LTC1472 to work with either active-low or
active-high PCMCIA VCC switch control logic (see Applications Information for further details).
to ground. Both switches also have independent thermal
shutdown which limits the power dissipation to safe
levels.
VCC Switch Truth Table
VCC EN0
VCC EN1
VCC(OUT)
0
0
OFF
1
0
5V
0
1
3.3V
1
1
OFF
VCC Break-Before-Make Switch Control
THE VPP SWITCHING SECTION
The LTC1472 has built-in delays to ensure that the 3.3V
and 5V switch are non-overlapping. Further, the gate
charge pumps include circuity which ramps the NMOS
switches on slowly (400µs typical rise time) but turn off
much more quickly (typically 10µs).
The VPP switching section of the LTC1472 consists of the
following functional blocks:
VCC Bias, Oscillator and Gate Charge Pump
When either the 3.3V or 5V switch is enabled, a bias
current generator and high frequency oscillator are turned
on. An on-chip capacitive charge pump generates approximately 12V of gate drive for the internal low RDS(ON)
NMOS VCC switches from the 5VIN power supply. Therefore, an external 12V supply is not required to switch the
VCC output. The 5VIN supply current drops below 1µA
when both switches are turned off.
VCC Gate Charge and Discharge Control
Both VCC switches are designed to ramp on slowly (400µs
typical rise time). Turn off time is much quicker
(typically 10µs).
To ensure that both VCC NMOS switch gates are fully
discharged, program the switch to the high impedance
mode at least 100µs before turning off the 5VIN power
supply.
VCC Switch Protection
Two levels of protection are designed into each of the
power switches in the LTC1472. Both VCC switches are
protected against accidental short circuits with SafeSlot
fold-back current limit circuits which limit the output
current to typically 1A when the VCC(OUT) output is shorted
VPP Switch Input TTL-CMOS Converters
The VPP inputs are designed to accommodate a wide
range of 3V and 5V logic families. The input threshold
voltage is 1.4V with ≈ 100mV of hysteresis. The inputs
enable the bias generator, the gate charge pumps and the
protection circuitry. When the inputs are turned off, the
entire circuit is powered down and the VDD and VPPIN
supply currents drop below 1µA.
VPP Break-Before-Make Switch Control
The VPP input section has built-in delays to ensure that the
VPP switchs are non-overlapping. Further, the gate charge
pumps include circuitry which ramps the NMOS switches
on slowly but turns them off quickly.
VPP Bias, Oscillator and Gate Charge Pump
When either the VPPIN-VPPOUT or VCC(IN)-VPPOUT switch
is enabled, a bias current generator and high frequency
oscillator are turned on. An on-chip capacitive charge
pump generates approximately 23V of gate drive for the
internal low RDS(ON) NMOS VPPIN-VPPOUT switch from
the VPPIN power supply. The gate of the VCC(IN)-VPPOUT
NMOS switch is either powered by the external 12V
regulator (if left on) or automatically from a built-in charge
pump powered from the VDD supply when the external 12V
supply drops below 10V. The VDD supply current drops
below 1µA when switched to either the 0V or Hi-Z mode.
1472fa
8
LTC1472
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OPERATION
VPP Gate Charge and Discharge Control
The VPP switches are designed to ramp slowly (typically
tens of µs) between output modes to reduce supply
glitching when powering large capacitive loads.
cally 100mA when protecting the 12V VPPIN supply and
60mA when protecting the VCC(IN) supply. (Higher operating currents are allowed at higher output voltages). Both
switches also have thermal shutdown.
VPP Switch Truth Table
VPP Switch Protection
VPP EN0
VPP EN1
0
0
0V
0
1
VCC(IN)
1
0
VPPIN
1
1
Hi-Z
Both VPP power switches are protected against accidental
short circuits with SafeSlot fold-back current limit circuits
which limit the short-circuit (0V) output current to typi-
VPPOUT
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APPLICATIONS INFORMATION
The LTC1472 is a complete single slot VCC and VPP power
supply switch matrix with SafeSlot current limit protection
on both outputs. It is designed to interface directly with
industry standard PCMCIA card controllers and to industry standard 12V regulators.
10µH
COILCRAFT
DO1608-103
5V
100µF
10V
+
2
®
The XOR VCC input function allows the LTC1472 to interface directly to the active-low VCC control outputs of the
CL-PD6710 for 3.3V/5V voltage selection (see the VCC
Switch Truth Table). Therefore, no “glue” logic is required
to interface to this PCMCIA compatible controller.
The LTC1472 provides SafeSlot current-limit protection
for the LT1301 step-up regulator, the system 3.3V and 5V
regulators, the socket and the card. Further, depending
upon the system regulator’s own current limits, it may
allow the system power supplies to continue operation
during a card/slot short circuit without losing data, etc.
(12V)
7
VIN
SW
SENSE
SEL
LT1301
3
Interfacing to the CL-PD6710 and the LT 1301
Figure 1 shows the LTC1472 interfaced to a standard
PCMCIA slot controller and an LT1301 step-up switching
regulator. The LTC1472 accepts logic control directly
from the CL-PD6710 and in turn, controls the LT1301 to
provide clean 12V VPP programming power when required. The LT1301 is then shutdown (10µA standby
current) at all other times to conserve power.
6
MBRS130LT3
ILIM
SHDN
PGND
GND
8
1
4
+
0.1µF
5
NC
47µF
16V
TANT
0.1µF
3.3V
10k
0.1µF
3VIN
5V
SHDN
3VIN
0V, VCC,
12V, Hi-Z
VPPIN
5VIN
0.1µF
VPPOUT
VCC(IN)
0.1µF
VPP1
VPP2
LTC1472
CL-PD6710
PCMCIA
CARD SLOT
VDD
VPP_PGM
VPP EN0
VPP_VCC
VPP EN1
VCC(OUT)
VCC _3
VCC EN0
VCC(OUT)
VCC _5
VCC EN1
GND
OFF,
3.3V, 5V
10k
GND
+
VCC
VCC
1µF
TANT
LTC1472-F01
Figure 1. Direct Interface to Industry Standard PCMCIA
Controller and LT1301 Step-Up Switching Regulator
1472fa
9
LTC1472
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APPLICATIONS INFORMATION
Interfacing to “365” Type Controllers
at the VDD and 5VIN supply pins for proper operation and
should always be present when a card is powered (whether
it is a 5V or 3.3V only card).
The LTC1472 also interfaces directly with “365” type
controllers as shown in Figure 2. The VCC Enable inputs
are connected differently than to the CL-PD6710 controller because the “365” type controllers use active-high
logic control of the VCC switches (see the VCC Switch Truth
Table). No “glue logic” is required to interface to this type
of PCMCIA compatible controller.
If the 5V power must be turned off, for example, to enter
a 3.3V only full system “sleep” mode, the 5V supply must
be turned off at least 100µs after the VCC and VPP switches
have been programmed to the Hi-Z or 0V states. This
ensures that the gates of the NMOS switches are completely discharged.
12V Power Requirements
Also, the VCC switches cannot be operated properly without 5V power. They must be programmed to the off state
at least 100µs prior to turning the 5V supply off, or they
may be left in an indeterminate state.
Note that in Figure 2, a “local” 5V to 12V converter is not
used. The LTC1472 works equally well with or without
continuous 12V power. If the main power supply system
has 12V continuously available, simply connect it to the
VPPIN pin. Internal circuitry automatically senses its presence and uses it to switch the internal VPP switches.
Supply Bypassing
For best results, bypass the supply input pins with 1µF
capacitors as close as possible to the LTC1472. Sometimes, much larger capacitors are already available at the
outputs of the 3.3V, 5V and 12V power supply. In this case,
it is still good practice to use 0.1µF capacitors as close as
possible to the LTC1472, especially if the power supply
output capacitors are more than 2" away on the printed
circuit board.
The 12V shutdown output can be used to shut down the
system 12V power supply (if not required for any purpose
other than VPP programming).
5V Power Requirements
The LTC1472 has been designed to operate without continuous 12V power, but continuous 5V power is required
12V
12V SHUTDOWN
(OPTIONAL)
10k
3.3V
0.1µF
3VIN
SHDN
3VIN
VPPIN
5VIN
5V
0.1µF
(0V, VCC, 12V, Hi-Z)
VPPOUT
0.1µF
VCC(IN)
LTC1472
“365”TYPE
CONTROLLER
VPP EN0
A_VPP_EN1
VPP EN1
A_VCC _EN0
VCC EN0
A_VCC _EN1
VCC EN1
GND
VCC(OUT)
(OFF, 3.3V, 5V)
VCC(OUT)
10k
GND
VPP2
PCMCIA
CARD SLOT
VDD
A_VPP_EN0
VPP1
+
1µF
TANT
VCC
VCC
LTC1472-F02
Figure 2. Direct Interface to Industry Standard PCMCIA Controller and LT1301 Step-Up Switching Regulator
1472fa
10
LTC1472
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APPLICATIONS INFORMATION
Output Capacitors
The VCC(OUT) pin is designed to ramp on slowly, typically
400µs rise time. Therefore, capacitors as large as 150µF
can be driven without producing voltage spikes on the
5VIN or 3VIN supply pins (see graphs in Typical Performance Characteristics). The VCC(OUT) pin should have a
0.1µF to 1µF capacitor for noise reduction and smoothing.
The VPPOUT pin should have a 0.01µF to 0.1µF capacitor
for noise reduction. The VPPIN capacitors should be at
least equal to the VPPOUT capacitors to ensure smooth
transitions between output voltages without creating spikes
on the system power supply lines.
Supply Sequencing
Because the 5V supply is the source of power for both the
VCC and VPP switch control logic, it is best to sequence the
power supplies such that the 5V supply is powered before
or simultaneous to the application of 3.3V or 12V power.
It is interesting to note however, that all of the switches in
the LTC1472 are NMOS transistors which require charge
pumps to generate gate voltages higher than the supply
rails for full enhancement. Because the gate voltages start
a 0V when the supplies are first activated, the switches
always start in the off state and do not produce glitches at
the output when powered.
Some PCMCIA switch matrix products employ PMOS
switches for 12V VPP control and great care must be taken
to ensure that the 5V control logic is powered before the
12V supply is turned on. If this sequence is not followed,
the PMOS VPP switch gate may start at ground potential
and the VPP output may be inadvertently forced to 12V.
Although, not advisable, it is possible to power the 12V
VPPIN supply pin of the LTC1472 prior to application of 5V
power. Only about 50µA flows to the VPPOUT pin under
these conditions.
If the 5V supply must be turned off, it is important to
program all switches to the Hi-Z or 0V state at least 100µs
before the 5V power is removed to ensure that all NMOS
switch gates are fully discharged to 0V.
Whenever possible however, it is best to leave the 5VIN and
VDD pins continuously powered. The LTC1472 quiescent
current drops to < 1µA with all the switches turned off and
therefore no 5V power is consumed in the standby mode.
1472fa
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LTC1472
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TYPICAL APPLICATIONS
Dual Protected PCMCIA Power Management System
33µH*
COILCRAFT
DO3316-333
3.3V or 5V
+
100µF
10V
6
2
3
MBRS130LT3
12V
7
VIN
SW
SENSE
SEL
LT1301
ILIM
SHDN
PGND
GND
8
1
4
+
0.1µF
5
NC
47µF
16V
TANT
0.1µF
3.3V
10k
0.1µF
3VIN
SHDN
3VIN
VPPIN
5VIN
5V
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
VCC(IN)
0.1µF
VPP1
VPP2
LTC1472
PCMCIA
CARD SLOT
VDD
A_VPP_PGM
VPP EN0
A_VPP_VCC
VPP EN1
A_VCC_3
VCC EN0
A_VCC_5
VCC EN1
GND
VCC(OUT)
OFF, 3.3V, 5V
VCC(OUT)
10k
+
GND
3.3V
10k
VCC
VCC
1µF
TANT
0.1µF
0.1µF
CL-PD6720
3VIN
SHDN
3VIN
5VIN
5V
VPPIN
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
VCC(IN)
0.1µF
VPP1
VPP2
LTC1472
PCMCIA
CARD SLOT
VDD
B_VPP_PGM
VPP EN0
B_VPP_VCC
VPP EN1
B_VCC _3
VCC EN0
B_VCC _5
VCC EN1
GND
VCC(OUT)
OFF, 3.3V, 5V
VCC(OUT)
10k
+
GND
1µF
TANT
VCC
VCC
LTC1472-TA02
*FOR 5V TO 12V CONVERSION USE 10µH, COILCRAFT DO1608-103. SEE LT1301 DATA SHEET
FOR MORE DETAILED INFORMATION ON INDUCTOR AND CAPACITOR SELECTION.
1472fa
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LTC1472
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TYPICAL APPLICATIONS
Single Protected PCMCIA Power Management System
Using the LT1301 Powered from 3.3V or 5V
33µH*
COILCRAFT
DO3316-333
3.3V OR 5V
+
100µF
10V
2
MBRS130LT3
6
7
VIN
SW
SEL
SENSE
LT1301
3
ILIM
SHDN
PGND
GND
8
1
12V
4
+
0.1µF
5
NC
47µF
16V
TANT
0.1µF
3.3V
10k
0.1µF
3VIN
5V
SHDN
3VIN
VPPIN
5VIN
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
VCC(IN)
0.1µF
LTC1472
CL-PD6710
VPP EN0
VPP_VCC
VPP EN1
VCC(OUT)
VCC _3
VCC EN0
VCC(OUT)
VCC _5
VCC EN1
GND
OFF, 3.3V, 5V
10k
GND
VPP2
PCMCIA
CARD SLOT
VDD
VPP_PGM
VPP1
+
1µF
TANT
VCC
VCC
LTC1472 TA03
*FOR 5V TO 12V CONVERSION USE 10µH, COILCRAFT D01608-103. SEE LT1301 DATA SHEET
FOR MORE DETAILED INFORMATION ON INDUCTION AND CAPACITOR SELECTION.
1472fa
13
LTC1472
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TYPICAL APPLICATIONS
Single Protected PCMCIA Power Management System
Using the LT1121 Powered from an Auxiliary Winding for 12V VPP Power
*13V TO 20V
(MAY BE FROM
AUXILIARY
WINDING)
+
8
10µF
10V
IN
5V
OUT
100k
12V
1
200pF
LT1121CS8
5
SHDN
ADJ
PGND
121k
2
GND
+
1µF
TANT
56.2k
3
6, 7
2N7002
3.3V
0.1µF
0.1µF
3VIN
5V
SHDN
3VIN
VPPIN
5VIN
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
VCC(IN)
0.1µF
VPP1
VPP2
LTC1472
CL-PD6710
PCMCIA
CARD SLOT
VDD
VPP_PGM
VPP EN0
VPP_VCC
VPP EN1
VCC(OUT)
VCC _3
VCC EN0
VCC(OUT)
VCC _5
VCC EN1
GND
OFF, 3.3V, 5V
10k
GND
+
1µF
TANT
VCC
VCC
LTC1472 TA04
*SEE THE LTC1142 DATA SHEET FOR AN EXAMPLE OF A 3.3V/5V DUAL REGULATOR WITH AUXILIARY WINDING 15V OUTPUT
1472fa
14
LTC1472
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TYPICAL APPLICATIONS
Dual Protected PCMCIA Power Management System
Powered by System 12V Supply
12V
0.1µF
3.3V
NC
0.1µF
3VIN
5V
SHDN
3VIN
VPPIN
5VIN
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
0.1µF
VCC(IN)
VPP1
VPP2
LTC1472
PCMCIA
CARD SLOT
VDD
A_VPP_PGM
VPP EN0
A_VPP_VCC
VPP EN1
VCC(OUT)
A_VCC _3
VCC EN0
VCC(OUT)
A_VCC _5
VCC EN1
GND
OFF, 3.3V, 5V
10k
+
GND
VCC
VCC
1µF
TANT
12V
0.1µF
CL-PD6720
3.3V
NC
0.1µF
3VIN
5V
SHDN
3VIN
VPPIN
5VIN
0.1µF
0V, VCC, 12V, Hi-Z
VPPOUT
0.1µF
VCC(IN)
VPP1
VPP2
LTC1472
PCMCIA
CARD SLOT
VDD
B_VPP_PGM
VPP EN0
B_VPP_VCC
VPP EN1
VCC(OUT)
B_VCC _3
VCC EN0
VCC(OUT)
B_VCC _5
VCC EN1
GND
OFF, 3.3V, 5V
10k
GND
+
1µF
TANT
VCC
VCC
LTC1472 TA05
1472fa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of circuits as described herein will not infringe on existing patent rights.
15
LTC1472
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PACKAGE DESCRIPTION
S Package
16-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.386 – .394
(9.804 – 10.008)
NOTE 3
.045 ±.005
.050 BSC
16
N
15
14
13
12
11
10
9
N
.245
MIN
.160 ±.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
1
.030 ±.005
TYP
2
3
N/2
N/2
RECOMMENDED SOLDER PAD LAYOUT
1
.010 – .020
× 45°
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
2
3
4
5
.053 – .069
(1.346 – 1.752)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
1. DIMENSIONS IN
7
8
.004 – .010
(0.101 – 0.254)
0° – 8° TYP
.016 – .050
(0.406 – 1.270)
6
S16 0502
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC3405/LTC3405A
LTC3405A-1.5
LTC3405A-1.8
300mA (IOUT), 1.5MHz, Synchronous Step-Down
DC/DC Converters
95% Efficiency, VIN = 2.7V to 6V, VOUT = 0.8V, IQ = 20µA
ISD = <1µA, ThinSOT Package
LTC3406/LTC3406B
600mA (IOUT) 1.5MHz, Synchronous Step-Down
DC/DC Converter
95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 0.6V, IQ = 20µA
ISD = <1µA, ThinSOT Package
LTC3411
1.25A (IOUT), 4MHz, Synchronous Step-Down
DC/DC Converter
95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 0.8V, IQ = 60µA
ISD = <1µA, MS10 Package
LTC3412
2.5A (IOUT), 4MHz, Synchronous Step-Down
DC/DC Converter
95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 0.8V, IQ = 60µA
ISD = <1µA, TSSOP16E Package
LTC3413
3A (IOUT), Sink/Source, 2MHz, Monolithic Synchronous
Regulator for DDR/QDR Memory Termination
90% Efficiency, VIN = 2.25V to 5.5V, VOUT = VREF/2, IQ = 280µA
ISD = <1µA, TSSOP16E Package
LT3430
60V, 2.75A (IOUT), 200kHz, High Efficiency Step-Down
DC/DC Converter
90% Efficiency, VIN = 5.5V to 60V, VOUT = 1.20V, IQ = 2.5mA
ISD = 25µA, TSSOP16E Package
LTC3440
600mA (IOUT), 2MHz, Synchronous Buck-Boost
DC/DC Converter
95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 2.5V, IQ = 25µA
ISD = <1µA, MS Package
1472fa
16
Linear Technology Corporation
LT/LT 0705 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1995