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LTC1472 Protected PCMCIA VCC and VPP Switching Matrix
FEATURES
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DESCRIPTION
The LTC(R)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 1A 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.
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 150F Loads) Continuous 12V Power Not Required Extremely Low RDS(ON) NMOS Switches Guaranteed 1A VCC Current and 120mA VPP Current 1A Quiescent Current in Standby No External Components Required Compatible with Industry Standard Controllers Break-Before-Make Switching Controlled Rise and Fall Times
APPLICATIONS
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Notebook Computers Palmtop Computers Pen-Based Computers Handi-Terminals Bar-Code Readers
TYPICAL APPLICATION
Protected PCMCIA VCC and VPP Card Driver
3.3V 0.1F 3VIN 5V 0.1F VPPOUT LTC1472 VDD VPP EN0 PCMCIA CARD SLOT CONTROLLER VPP EN1 VCC EN0 VCC(IN) VCC(OUT) OFF, 3.3V, 5V 5VIN VPPIN SHDN TO 12V REGULATOR OV, VCC, 12V, Hi-Z VPP1 0.1F VPP2 PCMCIA CARD SLOT VCC VCC 0.1F 12V
Linear Technology PCMCIA Product Family
DEVICE LT 1312 LT1313 LTC1314 LTC1315 LTC1470 LTC1471 LTC1472
LTC1472-TA01
DESCRIPTION Single PCMCIA VPP Driver/Regulator Dual PCMCIA VPP Driver/Regulator Single PCMCIA Switch Matrix Dual PCMCIA Switch Matrix Protected VCC 5V/3.3V Switch Matrix Dual Protected VCC 5V/3.3V Switch Matrix Protected VCC and VPP Switch Matrix
(R)
VCC EN1 GND
+
10k 1F
*Narrow Body
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PACKAGE 8-Pin SO 16-Pin SO* 14-Pin SO 24-Pin SSOP 8-Pin SO 16-Pin SO* 16-Pin SO*
1
LTC1472
ABSOLUTE MAXIMUM RATINGS
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 7V VPPOUT Short-Circuit Duration ........................ Indefinite VCC(OUT) Short-Circuit Duration ....................... Indefinite Operating Temperature Range ..................... 0C to 70C Junction Temperature........................................... 100C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
PACKAGE/ORDER INFORMATION
TOP VIEW VCC(OUT) 1 5VIN 2 VCC EN1 3 VCC EN0 4 VPPIN 5 SHDN 6 VPP EN0 7 VPP EN1 8 16 VCC(OUT) 15 3VIN 14 3VIN 13 GND 12 VCC(IN) 11 VPPOUT 10 GND 9 VDD
ORDER PART NUMBER LTC1472CS
S PACKAGE 16-LEAD PLASTIC SO TJMAX = 100C, JA = 100C/W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS (VCC Switch Section)
5VIN = 5V, 3VIN = 3.3V, VPP EN0 = VPP EN1 = OV, TA = 25C, (Note 1) unless otherwise noted.
SYMBOL 5VIN 3VIN I5VIN PARAMETER 5VIN Supply Voltage Range 3VIN Supply Voltage Range 5VIN Supply Current CONDITIONS (Note 2) (Note 3) Program to Hi-Z Program to 5V, No Load Program to 3.3V, No Load Program to Hi-Z. Program to 5V, No Load Program to 3.3V, No Load Program to 5V, IOUT = 500mA Program to 3.3V, IOUT = 500mA VCC EN0 = VCC EN1 = 0V or 5V, 0V VCC(OUT) 5V Program to 5V, VCC(OUT) = 0V (Note 4) Program to 3.3V, VCC(OUT) = 0V (Note 4)
q q q q q q q q q
MIN 4.75 0
TYP
MAX 5.25 3.60
UNITS V V A A A A A A A A A V
0.01 140 100 0.01 0.01 40 0.14 0.12 1 1 2
10 200 160 10 10 80 0.18 0.16 10
I3VIN
3VIN Supply Current
RON ILKG ILIM5V ILIM3V VCCENH VCCENL IVCCEN tVCC1 tVCC2 tVCC3
5V Switch On Resistance 3.3V Switch On Resistance Output Leakage Current OFF VCC(OUT) 5V Current Limit VCC(OUT) 3.3V Current Limit VCC Enable Input High Voltage VCC Enable Input Low Voltage VCC Enable Input Current Delay + Rise Time Delay + Rise Time Delay + Rise Time
0.8 1 0.2 0.2 0.2 0.32 0.52 0.38 1 1 1
0V VCCEN 5V From 0V to 3.3V, RLOAD = 100, CLOAD = 1F (Note 5) From 3.3V to 5V, RLOAD = 100, CLOAD = 1F (Note 5) From 0V to 5V, RLOAD = 100, CLOAD = 1F (Note 5)
q
2
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W
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WW
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V A ms ms ms
LTC1472
ELECTRICAL CHARACTERISTICS
SYMBOL VCC(IN) VPPIN VDD ICCIN IPPIN IDD PARAMETER VCC Input Voltage Range VPP Input Voltage Range Logic Supply Voltage Range VCC(IN) Supply Current, No Load VPPIN Supply Current, No Load VDD Supply Current, No Load (Note 6) (Note 7) Program to VPPIN or VCC(IN) VPPIN = 12V Program to 0V or Hi-Z Program to VPPIN or VCC(IN) Program to 0V or Hi-Z Program to VPPIN Program to VCC(IN), VPPIN = 0V Program to VCC(IN), VPPIN = 12V Program to 0V or Hi-Z Program to Hi-Z, 0V < VPPOUT < 12V VPPIN = 12V, ILOAD = 120mA VCC(IN) = 5V, ILOAD = 5mA VDD = 5V, ISINK = 1mA VDD = 5V VDD = 5V 0V < VPP EN < VDD Program to 0V, VCC(IN) or Hi-Z, ILOAD = 400A Program to VPPIN, ISINK = 400A Program to VCC(IN), VPPOUT = 0V (Note 4) Program to VPPIN, VPPOUT = 0V (Note 4) From 0V to VCC(IN),VPPIN = 0V (Note 8) From 0V to VPPIN (Note 8) From VCC(IN) to VPPIN (Note 8) From VPPIN to VCC(IN) (Note 9) From VPPIN to 0V (Note 10) From VCC(IN) to 0V, VPPIN = 0V (Note 10) From Hi-Z to VCC(IN) (Note 8) From Hi-Z to VPPIN (Note 8) 5 25 30 5 10 10 5 25
q q q q q
(VPP Switch Section)
VDD = 5V, VCC(IN) = 5V, VPPIN = 12V, VCCEN0 = VCCEN1 = 0V, TA= 25C, (Note 1), unless otherwise noted.
CONDITIONS
q q q q q q q q q q q q
MIN 3 0 4.5
TYP
MAX 5.5 12.6 5.5
UNITS V V V A A A A A A A A A V V A V V mA mA
35 0.01 40 0.01 70 85 40 0.01 0.01 0.50 1.70 100 2
60 10 80 10 120 150 80 10 10 1 5 250 0.8 1
IVPPOUT RON
Hi-Z Output Leakage Current On Resistance VPPOUT to VPPIN On Resistance VPPOUT to VCC(IN) On Resistance VPPOUT to GND VPP Enable Input High Voltage VPP Enable Input Low Voltage VPP Enable Input Current SHDN Output High Voltage SHDN Output Low Voltage VPPOUT Current Limit, VCC(IN) VPPOUT Current Limit, VPPIN Delay and Rise Time Delay and Rise Time Delay and Rise Time Delay and Fall Time Delay and Fall Time Delay and Fall Time Output Turn-On Delay Output Turn-On Delay
VPPENH VPPENL IVPPEN VSDH VSDL ILIMVCC ILIMVPP tVPP1 tVPP2 tVPP3 tVPP4 tVPP5 tVPP6 tVPP7 tVPP8
3.5 0.4 60 100 15 85 100 15 35 30 15 85 50 250 300 50 100 100 50 250
s s s s s s s s
The q denotes the specifications which apply over the full operating temperature range. Note 1: VENH = 5V, VENL = 0V. See VCC and VPP Switch Truth Tables for programming enable inputs for desired output states. Note 2: 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 3: 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 4: 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.
Note 5: To 90% of final value. Note 6: 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 7: Power for the VPP input logic and charge pump circuitry is derived from the VDD power supply which must be continuously powered. Note 8: To 90% of the final value, COUT = 0.1F, ROUT = 2.9k. Note 9: To 10% of the final value, COUT = 0.1F, ROUT = 2.9k. Note 10: To 50% of the initial value, COUT = 0.1F, ROUT = 2.9k.
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LTC1472
TYPICAL PERFORMANCE CHARACTERISTICS
5VIN Supply Current (OFF)
5 4 3 2 1 0 -1 TA = 25C VCC(OUT) PROGRAMMED TO OFF 300 250 200 150 100 50 0 0 1 5 2 3 4 5VIN SUPPLY VOLTAGE (V) 6 TA = 25C VCC(OUT) PROGRAMMED TO 5V, NO LOAD
5VIN SUPPLY CURRENT (A)
5VIN SUPPLY CURRENT (A)
5VIN SUPPLY CURRENT (A)
3VIN Supply Current (OFF)
5 4 3 2 1 0 -1 0 TA = 25C OUTPUT PROGRAMMED TO OFF 120 100 80 60 40 20 0 3 1 2 3VIN SUPPLY VOLTAGE (V) 4
LTC1472 TPC04
3VIN SUPPLY CURRENT (A)
3VIN SUPPLY CURRENT (A)
5V SWITCH RESISTANCE ()
3.3V 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 VCC(OUT) PROGRAMMED TO 3.3V
3.3V SWITCH RESISTANCE ()
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(VCC Section) VPP EN0 = VPP EN1 = 0V 5VIN Supply Current (3.3V ON)
300 250 200 150 100 50 0 TA = 25C VCC(OUT) PROGRAMMED TO 3.3V, NO LOAD
5VIN Supply Current (5V ON)
0
1
5 2 3 4 5VIN SUPPLY VOLTAGE (V)
6
0
1
5 2 3 4 5VIN SUPPLY VOLTAGE (V)
6
LTC1472 TPC01
LTC1472 TPC02
LTC1472 TPC03
3VIN Supply Current (3.3V ON)
0.30
5V Switch Resistance
VCC(OUT) PROGRAMMED TO 5V
TA = 25C VCC(OUT) PROGRAMMED TO 3.3V, NO LOAD
0.25 0.20 0.15 0.10 0.05 0
0
3 1 2 3VIN SUPPLY VOLTAGE (V)
4
LTC1472 TPC05
0
25 50 75 100 JUNCTION TEMPERATURE (C)
125
LT1472 TPC06
Inrush Current (5V Switch)
3 2 1 0 COUT = 150F ROUT = 10 COUT = 15F ROUT = 10 CURRENT LIMITED TJ = 25C
Inrush Current (3.3V Switch)
3 TJ = 25C 2 1 0 COUT = 15F ROUT = 6.6 COUT = 150F ROUT = 6.6
6 4 2 0 - 0.2
6 4 2
COUT = 150F ROUT = 6.6 0 0.2 0.4 0.6 0.8 TIME (ms) 1.0 1.2 1.4
0
0.2
0.4 0.6 0.8 TIME (ms)
1.0
1.2 1.4
0 - 0.2
LT1472 TPC07
LTC1472 TPC08
LTC1472 TPC09
LTC1472
TYPICAL PERFORMANCE CHARACTERISTICS (VPP Section) VCC EN0 = VCC EN1 = 0V
VCC(IN) Supply Current (No Load)
100 TA = 25C
VCC(IN) SUPPLY CURRENT (A)
5 4 3 2 1 0 -1 TA = 25C VPPOUT PROGRAMMED TO 0V OR Hi-Z
VPPIN SUPPLY CURRENT (A)
VPPIN SUPPLY CURRENT (A)
80 60 40 20 0 -20 VPPOUT PROGRAMMED TO 0V OR Hi-Z 0 1 5 3 4 VCC(IN) SUPPLY VOLTAGE (V) 2 6 VPPOUT PROGRAMMED TO VPPIN OR VCC(IN)
VDD Supply Current (OFF)
5 4 TA = 25C VPPOUT PROGRAMMED TO 0V OR Hi-Z
120 100
VDD SUPPLY CURRENT (A)
VDD SUPPLY CURRENT (A)
3 2 1 0 -1
80 60 40 20 0
VDD SUPPLY CURRENT (A)
0
1
2 3 4 5 VDD SUPPLY VOLTAGE (V)
SWITCH RESISTANCE ()
UW
LTC1472 TPC10
VPPIN Supply Current (OFF)
120 100 80 60 40 20 0
VPPIN Supply Current (No Load)
TA = 25C VPPIN = 12V NO LOAD
VPPOUT PROGRAMMED TO VPPIN
VPPOUT PROGRAMMED TO VCC(IN) 0 2 8 6 10 4 VPPIN SUPPLY VOLTAGE 12 14
0
2
8 6 10 4 VPPIN SUPPLY VOLTAGE
12
14
LTC1472 TPC11
LTC1472 TPC12
VDD Supply Current (No Load)
120
TA = 25C VPPOUT PROGRAMMED TO VPPIN, NO LOAD
VDD Supply Current (ON)
100 80 60 40 VPPIN = 12V 20 0 VPPIN = 0V TA = 25C VPPOUT PROGRAMMED TO VPPIN, NO LOAD
6
0
1
5 2 3 4 VDD SUPPLY VOLTAGE (V)
6
0
1
2 3 4 5 VDD SUPPLY VOLTAGE (V)
6
LTC1472 TPC13
LTC1472 TPC14
LTC1472 TPC15
Switch Resistances
10
VCCIN TO VPPOUT
1
VPPIN TO VPPOUT
0.1 0 20 40 60 TEMPERATURE (C) 80 100
LTC1472 TPC16
5
LTC1472
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 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 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 0.1A when the VPPOUT pin is programmed to 0V or Hi-Z and only rises to micropower levels when the VPP switches are active. VCC(IN) Supply (Pin 12) 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. 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 VCC switches, this pin must be continuously powered. The enable inputs should be turned off (both asserted high or both asserted low) at least 100s 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
BLOCK DIAGRAM W
5VIN GATE CHARGE AND DISCHARGE CONTROL LOGIC TTL-TO-CMOS CONVERTER 0.14 BREAK-BEFOREMAKE SWITCH AND CONTROL OSCILLATOR AND BIAS CHARGE PUMP CURRENT LIMIT AND THERMAL SHUTDOWN VCC(OUT) GATE CHARGE AND DISCHARGE CONTROL LOGIC 0.12 3VIN VDD SHDN TTL-TO-CMOS CONVERTER BREAK-BEFOREMAKE SWITCH VPP EN1 TTL-TO-CMOS CONVERTER GATE CHARGE AND DISCHARGE CONTROL LOGIC VPPIN CHARGE PUMP 0.5 OSCILLATOR AND BIAS CURRENT LIMIT AND THERMAL SHUTDOWN VCC(IN)
VCC EN0
VCC EN1
TTL-TO-CMOS CONVERTER
VPP EN0
VPPIN
+
10V
GATE CHARGE AND DISCHARGE CONTROL LOGIC
CHARGE PUMP
1.7 VPPOUT 100
-
LTC1470-BD01
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 1A.
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LTC1472
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 (400s typical rise time) but turn off much more quickly (typically 10s). 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 1A when both switches are turned off. VCC Gate Charge and Discharge Control Both VCC switches are designed to ramp on slowly (400s typical rise time). Turn off time is much quicker (typically 10s). To ensure that both VCC NMOS switch gates are fully discharged, program the switch to the high impedance mode at least 100s 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 to ground. Both switches also have independent thermal shutdown which limits the power dissipation to safe levels.
VCC Switch Truth Table
VCC EN0 0 1 0 1 VCC EN1 0 0 1 1 VCC(OUT) OFF 5V 3.3V OFF
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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 VPPIN supply currents drop below 1A. 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 1A when switched to either the 0V or Hi-Z mode.
LTC1472
OPERATION
VPP Gate Charge and Discharge Control The VPP switches are designed to ramp slowly (typically tens of s) 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 typically 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 EN0 0 0 1 1 VPP EN1 0 1 0 1 VPPOUT 0V VCC(IN) VPPIN Hi-Z
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(R)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 (10A 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 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.
10H COILCRAFT DO1608-103 5V 100F 10V MBRS130LT3 (12V) 7 SW SENSE LT1301 SHDN PGND 8 ILIM GND 1 0.1F 3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN SHDN VPPIN VPPOUT VCC(IN) LTC1472 CL-PD6710 VPP_PGM VPP_VCC VCC _3 VCC _5 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND GND VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V VCC VCC PCMCIA CARD SLOT 0.1F 0V, VCC, 12V, Hi-Z 10k 4
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W
U
U
U
+
2 SEL
6 VIN
+
5 NC 0.1F
3
47F 16V TANT
VPP1 VPP2
+
1F TANT
LTC1472-F01
Figure 1. Direct Interface to Industry Standard PCMCIA Controller and LT1301 Step-Up Switching Regulator
9
LTC1472
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 100s 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 100s 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 1F 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 0.1F 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.
12V 12V SHUTDOWN (OPTIONAL) 3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN SHDN VPPIN VPPOUT VCC(IN) LTC1472 "365"TYPE CONTROLLER A_VPP_EN0 A_VPP_EN1 A_VCC _EN0 A_VCC _EN1 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND VCC(OUT) VCC(OUT) 10k GND (OFF, 3.3V, 5V) VCC VCC
LTC1472-F02
Figure 2. Direct Interface to Industry Standard PCMCIA Controller and LT1301 Step-Up Switching Regulator
10
U
W
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U
10k
(0V, VCC, 12V, Hi-Z) 0.1F
VPP1 VPP2 PCMCIA CARD SLOT
+
1F TANT
LTC1472
APPLICATIONS INFORMATION
Output Capacitors The VCC(OUT) pin is designed to ramp on slowly, typically 400s rise time. Therefore, capacitors as large as 150F 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 0.1F to 1F capacitor for noise reduction and smoothing. The VPPOUT pin should have a 0.01F to 0.1F 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 50A 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 100s 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 < 1A with all the switches turned off and therefore no 5V power is consumed in the standby mode.
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11
LTC1472
TYPICAL APPLICATIONS
Dual Protected PCMCIA Power Management System
33H* COILCRAFT DO3316-333 3.3V or 5V
3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN
A_VPP_PGM A_VPP_VCC A_VCC_3 A_VCC_5
3.3V 0.1F CL-PD6720 5V 0.1F 3VIN 5VIN 3VIN
B_VPP_PGM B_VPP_VCC B_VCC _3 B_VCC _5
*FOR 5V TO 12V CONVERSION USE 10H, COILCRAFT DO1608-103. SEE LT1301 DATA SHEET FOR MORE DETAILED INFORMATION ON INDUCTOR AND CAPACITOR SELECTION.
12
U
+
MBRS130LT3 12V 7
100F 10V 2
6 VIN SEL LT1301 SHDN PGND 8
SW SENSE ILIM GND 1
4
+
5 NC 0.1F
3
47F 16V TANT
0.1F 10k SHDN VPPIN VPPOUT VCC(IN) LTC1472 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND VCC(OUT) VCC(OUT) 10k GND OFF, 3.3V, 5V VCC VCC PCMCIA CARD SLOT 0V, VCC, 12V, Hi-Z 0.1F
VPP1 VPP2
+
1F TANT
10k
0.1F
SHDN VPPIN VPPOUT VCC(IN) 0V, VCC, 12V, Hi-Z 0.1F VPP1 VPP2 PCMCIA CARD SLOT VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V
LTC1472 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND VCC VCC
LTC1472-TA02
+
GND
1F TANT
LTC1472
TYPICAL APPLICATIONS
Single Protected PCMCIA Power Management System Using the LT1301 Powered from 3.3V or 5V
33H* COILCRAFT DO3316-333 3.3V OR 5V
+
3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN
CL-PD6710 VPP_PGM VPP_VCC VCC _3 VCC _5
*FOR 5V TO 12V CONVERSION USE 10H, COILCRAFT D01608-103. SEE LT1301 DATA SHEET FOR MORE DETAILED INFORMATION ON INDUCTION AND CAPACITOR SELECTION.
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MBRS130LT3
12V
100F 10V 2
6 VIN SEL LT1301 SHDN PGND 8
7 SW SENSE 4
+
5 NC 0.1F
3
ILIM GND 1
47F 16V TANT
0.1F 10k SHDN VPPIN VPPOUT VCC(IN) LTC1472 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND GND VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V VCC VCC
LTC1472 TA03
0V, VCC, 12V, Hi-Z 0.1F
VPP1 VPP2 PCMCIA CARD SLOT
+
1F TANT
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LTC1472
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)
+
10F 10V
2N7002
3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN SHDN VPPIN VPPOUT VCC(IN) LTC1472 CL-PD6710 VPP_PGM VPP_VCC VCC _3 VCC _5 VDD VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND GND VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V VCC VCC
LTC1472 TA04
*SEE THE LTC1142 DATA SHEET FOR AN EXAMPLE OF A 3.3V/5V DUAL REGULATOR WITH AUXILIARY WINDING 15V OUTPUT
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5V
8 IN OUT 100k 5 LT1121CS8 SHDN PGND 6, 7 ADJ GND 3 2 56.2k 1 200pF 121k 12V
+
1F TANT
0.1F
0V, VCC, 12V, Hi-Z 0.1F
VPP1 VPP2 PCMCIA CARD SLOT
+
1F TANT
LTC1472
TYPICAL APPLICATIONS
Dual Protected PCMCIA Power Management System Powered by System 12V Supply
12V 0.1F 3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN SHDN VPPIN VPPOUT VCC(IN) LTC1472 VDD A_VPP_PGM A_VPP_VCC A_VCC _3 A_VCC _5 VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND GND VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V VCC VCC PCMCIA CARD SLOT 0V, VCC, 12V, Hi-Z 0.1F
12V 0.1F 3.3V 0.1F 3VIN 5V 0.1F 5VIN 3VIN SHDN VPPIN VPPOUT VCC(IN) LTC1472 VDD B_VPP_PGM B_VPP_VCC B_VCC _3 B_VCC _5 VPP EN0 VPP EN1 VCC EN0 VCC EN1 GND GND VCC(OUT) VCC(OUT) 10k OFF, 3.3V, 5V VCC VCC
LTC1472 TA05
CL-PD6720
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.
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NC
VPP1 VPP2
+
1F TANT
NC
0V, VCC, 12V, Hi-Z 0.1F
VPP1 VPP2 PCMCIA CARD SLOT
+
1F TANT
15
LTC1472
PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted.
S-Package 16-lead Plastic SOIC
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0 - 8 TYP
0.016 - 0.050 0.406 - 1.270
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm).
RELATED PARTS
See PCMCIA Product Family table on the first page of this data sheet.
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977
U
0.386 - 0.394* (9.804 - 10.008) 16 15 14 13 12 11 10 9
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157* (3.810 - 3.988)
1 0.053 - 0.069 (1.346 - 1.752)
2
3
4
5
6
7
8
0.004 - 0.010 (0.101 - 0.254)
0.014 - 0.019 (0.355 - 0.483)
0.050 (1.270) TYP
SO16 0893
LT/GP 0395 10K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1995

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