Datasheet LTC1472 Datasheet (Linear Technology)

LTC1472

FEATURES

■

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 R

■

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

NMOS Switches

DS(ON)

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APPLICATIONS

■

Notebook Computers

■

Palmtop Computers

■

Pen-Based Computers

■

Handi-Terminals

■

Bar-Code Readers

Protected PCMCIA V

CC

and

VPP Switching Matrix

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DESCRIPTION

The LTC®1472 switching matrix routes power to both the VCC and VPP power supply pins of the PCMCIA compatible card socket. The V 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.

The LTC1472 is available in 16-pin SO.

, LTC and LT are registered trademarks of Linear Technology Corporation.

SafeSlot is a trademark of Linear Technology Corporation.

output of the LTC1472 is switched

CC

TYPICAL APPLICATION

Protected PCMCIA VCC and VPP Card Driver

3.3V

5V

CARD SLOT

CONTROLLER

PCMCIA

0.1µF

3V

IN

5V

IN

LTC1472

V

DD

VPP EN0

VPP EN1 V

EN0

CC

V

EN1

CC

GND

VPP

SHDN

VPP

V

CC(IN)

V

CC(OUT)

IN

TO 12V REGULATOR OV, V

OUT

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0.1µF

, 12V, Hi-Z

CC

0.1µF

OFF, 3.3V, 5V

+

10k

12V

1µF

VPP1 VPP2

PCMCIA

CARD SLOT V

CC

V

CC

LTC1472-TA01

Linear Technology PCMCIA Product Family

DEVICE DESCRIPTION PACKAGE

LT®1312 Single PCMCIA VPP Driver/Regulator 8-Pin SO LT1313 Dual PCMCIA VPP Driver/Regulator 16-Pin SO* LTC1314 Single PCMCIA Switch Matrix 14-Pin SO LTC1315 Dual PCMCIA Switch Matrix 24-Pin SSOP LTC1470 Protected VCC 5V/3.3V Switch Matrix 8-Pin SO LTC1471 Dual Protected VCC 5V/3.3V Switch Matrix 16-Pin SO* LTC1472 Protected VCC and VPP Switch Matrix 16-Pin SO* *Narrow Body

1

LTC1472

TOP VIEW

S PACKAGE

16-LEAD PLASTIC SO



T

JMAX

= 100°C, θJA = 100°C/W

1 2 3 4 5 6 7 8

16 15 14 13 12 11 10

9

V

CC(OUT)



5V

IN



V

CC

EN1

V

CC

EN0

VPP

IN



SHDN VPP EN0 VPP EN1



V

CC(OUT)

3V

IN

3VIN GND V

CC(IN)

VPP

OUT

GND V

DD

WW

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ABSOLUTE MAXIMUM RATINGS

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PACKAGE/ORDER INFORMATION

5VIN Supply Voltage ................................... – 0.3V to 7V

3VIN Supply Voltage ................................... –0.3V to 7V

VPPIN Supply Voltage ............................ –0.3V to 13.2V

V V VPP V

Supply Voltage...................................–0.3 to 7V

CC(IN)

Supply Voltage ............................... –0.3V to 7V

DD(IN)

(OFF) ........................................ –0.3V to 13.2V

OUT

CC(OUT)

(OFF) ............................................ –0.3V to 7V

Enable Inputs.............................................. –0.3V to 7V

VPP V

Short-Circuit Duration ........................ Indefinite

OUT

CC(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

ELECTRICAL CHARACTERISTICS

5VIN = 5V, 3VIN = 3.3V, VPP EN0 = VPP EN1 = OV, TA = 25°C, (Note 1) unless otherwise noted.

(VCC Switch Section)

Consult factory for Industrial and Military grade parts.

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ORDER PART

NUMBER

LTC1472CS

W

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SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

5V

IN

3V

IN

I

5VIN

I

3VIN

R

ON

I

LKG

I

LIM5V

I

LIM3V

V

CCENH

V

CCENL

I

VCCEN

t

VCC1

t

VCC2

t

VCC3

2

5VIN Supply Voltage Range (Note 2) 4.75 5.25 V 3VIN Supply Voltage Range (Note 3) 0 3.60 V 5VIN Supply Current Program to Hi-Z ● 0.01 10 µA

Program to 5V, No Load Program to 3.3V, No Load

3VIN Supply Current Program to Hi-Z. ● 0.01 10 µA

Program to 5V, No Load Program to 3.3V, No Load

5V Switch On Resistance Program to 5V, I

3.3V Switch On Resistance Program to 3.3V, I Output Leakage Current OFF V V

5V Current Limit Program to 5V, V

CC(OUT)

V

3.3V Current Limit Program to 3.3V, V

CC(OUT)

VCC Enable Input High Voltage ● 2V V

Enable Input Low Voltage ● 0.8 V

CC

V

Enable Input Current 0V ≤ V

CC

Delay + Rise Time From 0V to 3.3V, R Delay + Rise Time From 3.3V to 5V, R Delay + Rise Time From 0V to 5V, R

EN0 = V

CC

CCEN

= 500mA 0.14 0.18 Ω

OUT

= 500mA 0.12 0.16 Ω

OUT

EN1 = 0V or 5V, 0V ≤ V

CC

= 0V (Note 4) 1 A

CC(OUT)

= 0V (Note 4) 1 A

CC(OUT)

≤ 5V ● ±1 µA

= 100Ω, C

LOAD

= 100Ω, C

LOAD

≤ 5V ● ±10 µA

CC(OUT)

= 1µF (Note 5) 0.2 0.32 1 ms = 1µF (Note 5) 0.2 0.52 1 ms

= 1µF (Note 5) 0.2 0.38 1 ms

● 140 200 µA

● 100 160 µA

● 0.01 10 µA

● 40 80 µA

LTC1472

ELECTRICAL CHARACTERISTICS

VDD = 5V, V

= 5V, VPPIN = 12V, V

CC(IN)

CCEN0

= V

CCEN1

(VPP Switch Section)

= 0V, TA= 25°C, (Note 1), unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC(IN)

VPP V

DD

I

CCIN

I

PPIN

I

DD

I

VPPOUT

R

ON

VPP VPP I

VPPEN

V

SDH

V

SDL

I

LIMVCC

I

LIMVPP

t

VPP1

t

VPP2

t

VPP3

t

VPP4

t

VPP5

t

VPP6

t

VPP7

t

VPP8

IN

ENH

ENL

VCC Input Voltage Range ● 3 5.5 V VPP Input Voltage Range (Note 6) ● 0 12.6 V Logic Supply Voltage Range (Note 7) ● 4.5 5.5 V V

Supply Current, No Load Program to VPPIN or V

CC(IN)

Program to 0V or Hi-Z

VPPIN Supply Current, No Load Program to VPPIN or V

Program to 0V or Hi-Z

VDD Supply Current, No Load Program to VPP

Program to V Program to V

IN

, VPPIN = 0V ● 85 150 µA

CC(IN)

, VPPIN = 12V ● 40 80 µA

CC(IN)

Program to 0V or Hi-Z Hi-Z Output Leakage Current Program to Hi-Z, 0V < VPP On Resistance VPP

On Resistance VPP On Resistance VPP

to VPP

OUT OUT OUT

IN

to V

CC(IN)

to GND VDD = 5V, I

VPPIN = 12V, I

V

CC(IN)

= 120mA 0.50 1 Ω

LOAD

= 5V, I

= 5mA 1.70 5 Ω

LOAD

= 1mA 100 250 Ω

SINK

VPPIN = 12V ● 35 60 µA

CC(IN)

< 12V ● 0.01 10 µA

OUT

● 0.01 10 µA

● 40 80 µA

● 0.01 10 µA

● 70 120 µA

● 0.01 10 µA

VPP Enable Input High Voltage VDD = 5V ● 2V VPP Enable Input Low Voltage VDD = 5V ● 0.8 V VPP Enable Input Current 0V < VPP EN < VDD ● ±1 µA SHDN Output High Voltage Program to 0V, V SHDN Output Low Voltage Program to VPPIN, I VPP

Current Limit, V

OUT

VPP

Current Limit, VPP

OUT

CC(IN)

IN

Delay and Rise Time From 0V to V

Program to V

CC(IN)

Program to VPPIN, VPP

CC(IN)

or Hi-Z, I

CC(IN)

= 400µA ● 0.4 V

SINK

, VPP

= 0V (Note 4) 60 mA

OUT

= 0V (Note 4) 100 mA

OUT

= 400µA ● 3.5 V

LOAD

,VPPIN = 0V (Note 8) 5 15 50 µs Delay and Rise Time From 0V to VPPIN (Note 8) 25 85 250 µs Delay and Rise Time From V Delay and Fall Time From VPPIN to V

to VPPIN (Note 8) 30 100 300 µs

CC(IN)

(Note 9) 5 15 50 µs

CC(IN)

Delay and Fall Time From VPPIN to 0V (Note 10) 10 35 100 µs Delay and Fall Time From V Output Turn-On Delay From Hi-Z to V

to 0V, VPPIN = 0V (Note 10) 10 30 100 µs

CC(IN)

(Note 8) 5 15 50 µs

CC(IN)

Output Turn-On Delay From Hi-Z to VPPIN (Note 8) 25 85 250 µs

The ● denotes the specifications which apply over the full operating temperature range. Note 1: V

ENH

= 5V, V

= 0V. See VCC and VPP Switch Truth Tables for

ENL

programming enable inputs for desired output states. Note 2: Power for the V

from the 5V

power supply which must be continuously powered. 12V

IN

and 3.3V power is not required to control the NMOS V

input logic and charge pump circuitry is derived

CC

switches. (See

CC

Applications Information.) Note 3: The two 3V

together and the two V together. The 3V

supply input pins (14 and 15) must be connected

IN

supply pins do not need to be continuously powered

IN

output pins (1 and 16) must be connected

CC(OUT)

and may drop to 0V when not required. Note 4: The V

and VPP output are protected with foldback current limit

CC

which reduces the short-circuit (0V) currents below peak permissible current levels at higher output voltages.

Note 5: To 90% of final value. Note 6: 12V power is only required when VPP

is programmed to 12V.

OUT

The external 12V regulator can be shutdown at all other times. Built-in charge pumps power the internal NMOS switches from the 5V V

supply

DD

when 12V is not present. Note 7: Power for the VPP input logic and charge pump circuitry is derived

from the V

Note 8: To 90% of the final value, C Note 9: To 10% of the final value, C Note 10: To 50% of the initial value, C

power supply which must be continuously powered.

DD

= 0.1µF, R

OUT

= 0.1µF, R

OUT

= 0.1µF, R

OUT OUT

= 2.9k. = 2.9k.

= 2.9k.

OUT

3

LTC1472

TIME (ms)

–0.2

INRUSH CURRENT (A)OUTPUT VOLTAGE (V)



0

1

1.4

LTC1472 TPC09

6

4

0

0.2

0.6

1.0

2

3

2

0

0.4

0.8

1.2

C

OUT

= 150µF

R

OUT

= 6.6Ω

C

OUT

= 150µF

R

OUT

= 6.6Ω

C

OUT

= 15µF

R

OUT

= 6.6Ω

TJ = 25°C

5VIN SUPPLY VOLTAGE (V)

0

5V

IN

SUPPLY CURRENT (µA)

50

100

150

200

300

1

234

LTC1472 TPC03

56

250

TA = 25°C V

CC(OUT)

 PROGRAMMED TO 3.3V, NO LOAD

W

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TYPICAL PERFORMANCE CHARACTERISTICS

(VCC Section) VPP EN0 = VPP EN1 = 0V

5VIN Supply Current (OFF)

5

TA = 25°C V PROGRAMMED TO OFF

4

3

2

1

SUPPLY CURRENT (µA)

IN

5V

0

–1

0

5

T PROGRAMMED TO OFF

4

3

2

CC(OUT)

234

1

5VIN SUPPLY VOLTAGE (V)

= 25°C OUTPUT

A

5VIN Supply Current (5V ON) 5VIN Supply Current (3.3V ON)



56

LTC1472 TPC01

300

250

200

150

100

SUPPLY CURRENT (µA)

IN

5V

50

0

TA = 25°C V PROGRAMMED TO 5V, NO LOAD

0

1

5VIN SUPPLY VOLTAGE (V)



CC(OUT)

234

56

LTC1472 TPC02

5V Switch Resistance3VIN Supply Current (3.3V ON)3VIN Supply Current (OFF)

120

T PROGRAMMED TO

100

3.3V, NO LOAD

80

60

= 25°C V

A

CC(OUT)



0.30

0.25

0.20

0.15

V



CC(OUT)

PROGRAMMED TO 5V

SUPPLY CURRENT (µA) 3V

3.3V SWITCH RESISTANCE (Ω)

4

1

IN

0

–1



0

12

3VIN SUPPLY VOLTAGE (V)

3.3V Switch Resistance

0.30 V



CC(OUT)

PROGRAMMED

0.25 TO 3.3V

0.20

0.15

0.10

0.05

0

25 50 75 100

JUNCTION TEMPERATURE (°C)



3



LTC1472 TPC04

LT1472 TPC07

4

125

40

SUPPLY CURRENT (µA)

IN

3V

20

0



0

3

2

1

0

INRUSH CURRENT (A)OUTPUT VOLTAGE (V)



6

4

2

0 –0.2

12

3VIN SUPPLY VOLTAGE (V)

CURRENT

LIMITED

C

= 150µF

OUT

= 10Ω

R

OUT

0

0.2

0.6

0.4 TIME (ms)



C

OUT

R

OUT

0.8

1.0

3



LTC1472 TPC05

TJ = 25°C

= 15µF = 10Ω

1.2

LTC1472 TPC08

4

1.4

0.10

5V SWITCH RESISTANCE (Ω)

0.05

0

25 50 75 100 JUNCTION TEMPERATURE (°C)

125

LT1472 TPC06

Inrush Current (3.3V Switch)Inrush Current (5V Switch)

VPPIN SUPPLY VOLTAGE

0

VPP

IN

SUPPLY CURRENT (µA)

80

100

120

610

LTC1472 TPC12

60

40

24

81214

20

0

TA = 25°C VPP

IN

= 12V

NO LOAD

VPP

OUT

PROGRAMMED

TO V

CC(IN)

VPP

OUT

PROGRAMMED

TO VPP

IN

W

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TYPICAL PERFORMANCE CHARACTERISTICS

V

100

80

Supply Current (No Load)

CC(IN)

TA = 25°C

VPPIN Supply Current (OFF) VPPIN Supply Current (No Load)

5

TA = 25°C

PROGRAMMED

VPP

OUT

4

TO 0V OR Hi-Z

LTC1472

(VPP Section) VCC EN0 = VCC EN1 = 0V

3

2

1

SUPPLY CURRENT (µA)

IN

VPP

0

–1

0

24

610

VPPIN SUPPLY VOLTAGE

81214

SUPPLY CURRENT (µA)

CC(IN)

V

–20

60

VPP

PROGRAMMED

OUT

OR V

TO VPP

IN

40

20

0

VPP

OUT

TO 0V OR Hi-Z

234

1

V

SUPPLY VOLTAGE (V)

CC(IN)

PROGRAMMED

56

LTC1472 TPC10

VDD Supply Current (OFF) VDD Supply Current (No Load)

120

TA = 25°C

PROGRAMMED

VPP

100

SUPPLY CURRENT (µA)

DD

V

OUT

, NO LOAD

TO VPP

IN

80

60

40

20

0

234

1

VDD SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

DD

V

–1

5

TA = 25°C VPP

4

TO 0V OR Hi-Z

3

2

1

0

PROGRAMMED

OUT

234

1

VDD SUPPLY VOLTAGE (V)

56

LTC1472 TPC13

LTC1472 TPC11

56

LTC1472 TPC14

VDD Supply Current (ON)

120

TA = 25°C

PROGRAMMED

VPP

100

SUPPLY CURRENT (µA)

DD

V

OUT

, NO LOAD

TO VPP

IN

80

60

40

20

0

VPPIN = 0V

234

1

VDD SUPPLY VOLTAGE (V)

VPPIN = 12V

56

LTC1472 TPC15

Switch Resistances

10



1



SWITCH RESISTANCE (Ω)



0.1 020406080

VCCIN TO VPP

VPPIN TO VPP

TEMPERATURE (°C)

OUT

 100

LTC1472 TPC16

5

LTC1472

UUU

PIN FUNCTIONS

Enable Input (Pins 3,4,7,8)

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 below ground. Both sets of inputs have about 100mV of built-in hysteresis to ensure clean switching between operating modes.

Shutdown Output (Pin 6)

The LTC1472 is designed to operate 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 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.

without

continuous

V

The V V 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 V consume any power when unloaded or turned off.

5VIN Supply (Pin 2)

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 V switches,

The enable inputs should be turned off (both asserted high or both asserted low) at least 100µ s 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)

Supply (Pin 12)

CC(IN)

supply pin is typically connected directly to the

CC(IN)

CC(OUT)

pin from the VCC switch section of the LTC1472.

this pin must be continuously powered

CC(IN)

-VPP

switch and therefore does not

OUT

.

CC

VPPIN Supply (Pin 5)

The VPPIN supply pin serves two purposes. The first purpose is to provide power and gate drive for the VPPINVPP 12V gate drive for the V 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 0.1µ A when the VPP is programmed to 0V or Hi-Z and only rises to micropower levels when the VPP switches are active.

switch. The second purpose is to provide optional

OUT

CC(IN)

-VPP

switch. If, however,

OUT

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.

V

CC(OUT)

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.

and VPP

Output (Pins 1,11,16)

OUT

6

BLOCK DIAGRAM

W

LTC1472

5V

IN

V

CC

V

CC

EN0

EN1

V

SHDN

VPP EN0

VPP EN1

DD

TTL-TO-CMOS

CONVERTER

TTL-TO-CMOS

CONVERTER

TTL-TO-CMOS

CONVERTER

TTL-TO-CMOS

CONVERTER

VPP

10V

GATE CHARGE

AND

DISCHARGE

CONTROL LOGIC

BREAK-BEFORE-

MAKE SWITCH AND CONTROL

BREAK-BEFORE-

MAKE SWITCH



IN

+

OSCILLATOR

AND BIAS

GATE CHARGE

AND

DISCHARGE

CONTROL LOGIC

OSCILLATOR

AND BIAS

GATE CHARGE

AND

DISCHARGE

CONTROL LOGIC

CHARGE

PUMP

GATE CHARGE

AND

DISCHARGE

CONTROL LOGIC

CHARGE

PUMP

CURRENT LIMIT

AND THERMAL

SHUTDOWN

CHARGE

PUMP

CURRENT LIMIT

AND THERMAL

SHUTDOWN

1.7Ω

–

0.5Ω

0.14Ω

0.12Ω

VPP

VCC

VPP

V

CC(OUT)

3V

IN

(IN)

OUT

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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:

100Ω

LTC1470-BD01

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.

7

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).

VCC Break-Before-Make Switch Control

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).

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 R

DS(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 (400µ s 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 V

CC(OUT)

output is shorted

to ground. Both switches also have independent thermal shutdown which limits the power dissipation to safe levels.

VCC Switch Truth Table

V

EN0 V

CC

0 0 OFF 105V 0 1 3.3V 1 1 OFF

EN1 V

CC

CC(OUT)

THE VPP SWITCHING SECTION

The VPP switching section of the LTC1472 consists of the following functional blocks:

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 VPP

IN

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-VPP

OUT

or V

CC(IN)

-VPP

OUT

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 R the VPPIN power supply. The gate of the V

NMOS VPPIN-VPP

DS(ON)

switch from

OUT

-VPP

CC(IN)

OUT

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 1µ A when switched to either the 0V or Hi-Z mode.

8

U

3VIN3V

IN

SHDN

5V

IN

V

DD

VPP EN0

VPP EN1

V

CC

EN0

V

CC

EN1

VPP

IN

VPP

OUT

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

GND

LTC1472

V

IN

SEL

SHDN PGND

SW

SENSE

I

LIM

GND

LT1301

3.3V

0.1µF

5V

0.1µF

CL-PD6710

VPP_V

CC

VPP_PGM

V

CC

_3

V

CC

_5

PCMCIA

CARD SLOT

VPP1

VPP2

V

CC

V

CC

0.1µF

10k

1µF TANT

OFF,

3.3V, 5V

0.1µF

47µF 16V TANT

(12V)

100µF

10V

10µH

COILCRAFT

DO1608-103

3

2

10k

+

6

7

4

5

NC

MBRS130LT3

0V, V

CC

,

12V, Hi-Z

1

8

LTC1472-F01

OPERATION

LTC1472

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.

VPP Switch Protection

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-

U

WUU

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.

Interfacing to the CL-PD6710 and the LT®1301

cally 100mA when protecting the 12V VPPIN supply and 60mA when protecting the V

supply. (Higher operat-

CC(IN)

ing currents are allowed at higher output voltages). Both switches also have thermal shutdown.

VPP Switch Truth Table

VPP EN0 VPP EN1 VPP

000V 01V 1 0 VPP 1 1 Hi-Z

OUT

CC(IN)

IN

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.

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 V 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.

CC

Figure 1. Direct Interface to Industry Standard PCMCIA Controller and LT1301 Step-Up Switching Regulator

9

LTC1472

U

WUU

APPLICATIONS INFORMATION

Interfacing to “365” Type Controllers

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.

12V Power Requirements

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.

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

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).

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 100µ s 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.

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.

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 0.1µ F 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.

10

12V

12V SHUTDOWN

(OPTIONAL)

IN

V

SHDN

VPP

OUT

V

CC(IN)

CC(OUT)

10k

IN

10k

+

(0V, VCC, 12V, Hi-Z)

0.1µF

(OFF, 3.3V, 5V)

1µF TANT

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

LTC1472-F02

3.3V

5V

“365”TYPE

CONTROLLER

A_VPP_EN0

A_VPP_EN1 A_V

CC

A_V

CC

_EN0

_EN1

0.1µF

3VIN3V

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

V

EN1

CC

GND GND

LTC1472

Figure 2. Direct Interface to Industry Standard PCMCIA Controller and LT1301 Step-Up Switching Regulator

LTC1472

U

WUU

APPLICATIONS INFORMATION

Output Capacitors

The V

CC(OUT)

400µ s 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 V

0.1µF to 1µ F capacitor for noise reduction and smoothing. The VPP

for noise reduction. The VPPIN capacitors should be at least equal to the VPP 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

pin is designed to ramp on slowly, typically

CC(OUT)

pin should have a 0.01µF to 0.1µF capacitor

OUT

capacitors to ensure smooth

OUT

pin should have a

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 VPP 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 100µ s 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 < 1µ A with all the switches turned off and therefore no 5V power is consumed in the standby mode.

pin under

OUT

11

LTC1472

TYPICAL APPLICATIONS

Dual Protected PCMCIA Power Management System

3.3V or 5V

+

U

100µF 10V

2

SEL

3

SHDN

33µH*

COILCRAFT

DO3316-333

6

V

IN

LT1301

PGND

8

SW

SENSE

I

LIM

GND

1

7

MBRS130LT3

4

5

NC

0.1µF

12V

+

47µF 16V TANT

A_VPP_PGM

A_VPP_V

A_V

CC

A_V

CC

CL-PD6720

B_VPP_PGM

B_VPP_V

B_V

CC

B_V

CC

3.3V

0.1µF

3VIN3V

5V

0.1µF

CC

_3

_5

3.3V

0.1µF

5V

0.1µF

CC

_3

_5

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

EN1

V

CC

GND GND

3VIN3V

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

EN1

V

CC

GND GND

LTC1472

IN

SHDN

VPP

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

SHDN

VPP

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

10k

IN

OUT

10k

IN

OUT

10k

0.1µF

0V, V

0.1µF

+

1µF TANT

0.1µF

0V, VCC, 12V, Hi-Z

0.1µF

+

1µF TANT

, 12V, Hi-Z

CC

OFF, 3.3V, 5V

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

LTC1472-TA02

12

*FOR 5V TO 12V CONVERSION USE 10µH, COILCRAFT DO1608-103. SEE LT1301 DATA SHEET FOR MORE DETAILED INFORMATION ON INDUCTOR AND CAPACITOR SELECTION.

U

TYPICAL APPLICATIONS

Single Protected PCMCIA Power Management System

3.3V OR 5V

+

Using the LT1301 Powered from 3.3V or 5V

33µH*

100µF 10V

2

3

COILCRAFT

DO3316-333

6

V

IN

SEL

SHDN PGND

8

SW

SENSE

LT1301

I

GND

LIM

7

1

MBRS130LT3

4

5

NC

0.1µF

LTC1472

12V

+

47µF 16V TANT

+

0.1µF

0V, V

, 12V, Hi-Z

CC

0.1µF

OFF, 3.3V, 5V

1µF TANT

3.3V

0.1µF

3VIN3V

5V

0.1µF

CL-PD6710

VPP_PGM

VPP_V

CC

_3

V

CC

V

_5

CC

*FOR 5V TO 12V CONVERSION USE 10µH, COILCRAFT D01608-103. SEE LT1301 DATA SHEET

FOR MORE DETAILED INFORMATION ON INDUCTION AND CAPACITOR SELECTION.

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

V

EN1

CC

GND

LTC1472

IN

VPP

V

CC(OUT)

V

CC(OUT)

GND

SHDN VPP

OUT

CC(IN)

10k

IN

10k

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

LTC1472 TA03

13

LTC1472

U

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)

+

10µF 10V

5V

2N7002

100k

8

IN

LT1121CS8

5

SHDN PGND

6, 7

OUT

GND

ADJ

1

2

3

121k200pF

56.2k

12V

+

1µF TANT

3.3V

0.1µF

IN

LTC1472

SHDN VPP

VPP

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

GND

IN

OUT

10k

3VIN3V

5V

0.1µF

CL-PD6710

VPP_PGM

VPP_V

CC

V

_3

CC

V

_5

CC

*SEE THE LTC1142 DATA SHEET FOR AN EXAMPLE OF A 3.3V/5V DUAL REGULATOR WITH AUXILIARY WINDING 15V OUTPUT

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

V

EN1

CC

GND

+

0.1µF

0V, V

CC

0.1µF

OFF, 3.3V, 5V

1µF TANT

, 12V, Hi-Z

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

LTC1472 TA04

14

U

TYPICAL APPLICATIONS

Dual Protected PCMCIA Power Management System

12V

LTC1472

Powered by System 12V Supply

0.1µF

A_VPP_PGM

A_VPP_V

A_V

CC

A_V

CC

CL-PD6720

B_VPP_PGM

B_VPP_V

B_V

CC

B_V

CC

3.3V

0.1µF

3VIN3V

5V

0.1µF

CC

_3

_5

12V

3.3V

0.1µF

5V

0.1µF

CC

_3

_5

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

V

EN1

CC

GND

3VIN3V

5V

IN

V

DD

VPP EN0

VPP EN1

EN0

V

CC

V

EN1

CC

GND

LTC1472

IN

GND

IN

GND

SHDN VPP

VPP

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

SHDN VPP

VPP

V

CC(IN)

V

CC(OUT)

V

CC(OUT)

NC

OUT

IN

0.1µF

IN

10k

0V, VCC, 12V, Hi-Z

0.1µF

OFF, 3.3V, 5V

+

1µF TANT

0V, VCC, 12V, Hi-Z

0.1µF

OFF, 3.3V, 5V

+

1µF TANT

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

VPP1

VPP2

PCMCIA

CARD SLOT

V

CC

V

CC

LTC1472 TA05

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

PACKAGE DESCRIPTION

U

Dimensions in inches (millimeters) unless otherwise noted.

S-Package

16-lead Plastic SOIC

0.386 – 0.394* (9.804 – 10.008)

13

16

14

15

12

11 10

9

0.228 – 0.244

(5.791 – 6.197)

3

2

0.010 – 0.020

(0.254 – 0.508)

0.008 – 0.010

(0.203 – 0.254)

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm).

× 45°

0.016 – 0.050

0.406 – 1.270

0.053 – 0.069

(1.346 – 1.752)

0° – 8° TYP

0.014 – 0.019

(0.355 – 0.483)

1

RELATED PARTS

See PCMCIA Product Family table on the first page of this data sheet.

4

5

0.050

(1.270)

TYP

0.150 – 0.157* (3.810 – 3.988)

7

6

8

0.004 – 0.010

(0.101 – 0.254)

SO16 0893

16

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7487

(408) 432-1900

●

FAX

: (408) 434-0507

●

TELEX

: 499-3977

LT/GP 0395 10K • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 1995

Datasheet LTC1472 Datasheet (Linear Technology)

Specifications and Main Features

Frequently Asked Questions

User Manual