LTC1470/LTC1471 Single and Dual PCMCIA Protected 3.3V/5V VCC Switches U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LTC®1470 switches the VCC pins of a Personal Computer Memory Card International Association (PCMCIA) card slot between three operating states: OFF, 3.3V and 5V. Two low RDS(ON) N-channel power MOSFETs are driven by a built-in charge pump which generates a voltage higher than the supply voltage to fully enhance each switch when selected by the input control logic. Single 3.3V/5V Switch in 8-Pin SO Package Dual 3.3V/5V Switch in 16-Pin SO Package Built-In Current Limit and Thermal Shutdown Built-In Charge Pumps (No 12V Required) Extremely Low RDS(ON) MOSFET Switches Output Current Capability: 1A Inrush Current Limited (Drives 150µF Loads) Quiescent Current in Standby: 1µA No Parasitic Body Diodes Built-In XOR Function Eliminates “Glue” Logic Break-Before-Make Switching Controlled Rise and Fall Times The LTC1470 inputs are compatible with industry standard PCMCIA controllers. A built-in XOR ensures that both switches are never on at the same time. This function also makes the LTC1470 compatible with both active-low and active-high controllers (see Applications Information section). The switch rise times are controlled to eliminate power supply glitching. U APPLICATIONS ■ ■ ■ ■ ■ ■ The LTC1470 features built-in SafeSlotTM current limit and thermal shutdown. The output is limited to 1A during short circuit to ground but 2A of peak operating current is allowed. Notebook Computers Palmtop Computers Pen-Based Computers Handi-Terminals PC Card Reader/Writers 3.3V/5V Power Supply Switch The LTC1471 is a dual version of the LTC1470 and is available in a 16-pin SO package. , LTC and LT are registered trademarks of Linear Technology Corporation. SafeSlot is a trademark of Linear Technology Corporation. U TYPICAL APPLICATION Dual Slot PCMCIA 3.3V/5V VCC Switch 5V Linear Technology PCMCIA Product Family 3.3V 0.1µF 0.1µF VCC 5VIN 3VIN AOUT (Hi-Z/3.3V/5V) VCC + 1µF LTC1471 10k AEN1 PCMCIA CARD SLOT CONTROLLER VCC AEN0 BEN1 PCMCIA CARD SLOT (Hi-Z/3.3V/5V) BOUT BEN0 GND VCC PCMCIA CARD SLOT + 1µF 10k 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 Single Protected VCC 3.3V/5V Switch Matrix 8-Pin SO LTC1471 Dual Protected VCC 3.3V/5V Switch Matrix 16-Pin SO* LTC1472 Protected VCC and VPP Switch Matrix 16-Pin SO* *Narrow Body 1470/71 TA01 1 LTC1470/LTC1471 W W U W ABSOLUTE MAXIMUM RATINGS 3.3V Supply Voltage (Note 1) .................................. 7V 5V Supply Voltage (Note1) ....................................... 7V Enable Input Voltage ........................ 7V to (GND – 0.3V) Output Voltage (OFF) (Note 1) ......... 7V to (GND – 0.3V) Output Short-Circuit Duration .......................... Indefinite Operating Temperature ............................... 0°C to 70°C Junction Temperature .......................................... 100°C Storage Temperature Range ................ –65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C W U U PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW OUT 1 8 OUT 5VIN 2 7 3VIN EN1 3 6 3VIN EN0 4 5 LTC1470CS8 S8 PART MARKING GND S8 PACKAGE 8-LEAD PLASTIC SO 1470 ORDER PART NUMBER TOP VIEW AOUT 1 16 AOUT A5VIN 2 15 A3VIN AEN1 3 14 A3VIN AEN0 4 13 GND GND 5 12 BEN0 B3VIN 6 11 BEN1 B3VIN 7 10 B5VIN BOUT 8 9 TJMAX = 100°C, θJA = 150°C/W LTC1471CS BOUT S PACKAGE 16-LEAD PLASTIC SO TJMAX = 100°C, θJA = 100°C/W Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS 3VIN = 3.3V, 5VIN = 5V (Note 2), TA = 25°C, unless otherwise noted. SYMBOL PARAMETER MAX UNITS 3VIN 3.3V Supply Voltage Range 2.70 3.60 V 5VIN 5V Supply Voltage Range 4.75 5.25 V I3VIN 3.3V Supply Current Program to Hi-Z (Note 3) Program to 3.3V, No Load (Note 3) Program to 5V, No Load (Note 3) ● ● ● 0.01 40 0.01 10 80 10 µA µA µA I5VIN 5V Supply Current Program to Hi-Z (Note 3) Program to 3.3V (Note 3) Program to 5V (Note 3) ● ● ● 0.01 100 140 10 160 200 µA µA µA RON 3.3V Switch ON Resistance 5V Switch ON Resistance Program to 3.3V, IOUT = 500mA Program to 5V, IOUT = 500mA 0.12 0.14 0.16 0.18 Ω Ω ILKG Output Leakage Current OFF Program to Hi-Z, 0V ≤ VOUT ≤ 5V (Note 3) ±10 µA ILIM3V 3.3V Current Limit Program to 3.3V, VOUT = 0V (Note 4) ILIM5V 5V Current Limit Program to 5V, VOUT = 0V (Note 4) VENH Enable Input High Voltage ● VENL Enable Input Low Voltage ● 0.8 V IEN Enable Input Current ● ±1 µA 2 CONDITIONS 0V ≤ VEN ≤ 5V MIN TYP ● 1 A 1 A 2.0 V LTC1470/LTC1471 ELECTRICAL CHARACTERISTICS 3VIN = 3.3V, 5VIN = 5V (Note 2), TA = 25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS t0 to t3 Delay and Rise Time (Note 5) Transition from 0V to 3.3V, ROUT = 100Ω, COUT = 1µF 0.2 0.32 1.0 ms t3 to t5 Delay and Rise Time (Note 5) Transition from 3.3V to 5V, ROUT = 100Ω, COUT = 1µF 0.2 0.52 1.0 ms t0 to t5 Delay and Rise Time (Note 5) Transition from 0V to 5V, ROUT = 100Ω, COUT = 1µF 0.2 0.38 1.0 ms The ● denotes the specifications which apply over the full operating temperature range. Note 1: For the LTC1470, the two output pins (1, 8) must be connected together and the two 3.3V supply input pins (6 , 7) must be connected together. For the LTC1471, the two AOUT pins (1, 16) must be connected together, the two BOUT pins (8, 9) must be connected together, the two A3VIN supply input pins (14, 15) must be connected together, the two B3VIN supply pins (6, 7) must be connected together and the two GND pins (5, 13) must be connected together. Note 2: Power for the input logic and charge pump circuitry is derived from the 5VIN supply pin(s) which must be continuously powered. Note 3: Measured current is per channel with the other channel programmed off for the LTC1471. Note 4: The output is protected with foldback current limit which reduces the short-circuit (0V) currents below peak permissible current levels at higher output voltages. Note 5: To 90% of final value. U W TYPICAL PERFORMANCE CHARACTERISTICS 3VIN Supply Current (OFF) 3VIN Supply Current (3.3V ON) 3 2 1 –1 80 60 40 20 4 3 1 2 3VIN SUPPLY VOLTAGE (V) 0 1470/71 G04 5VIN Supply Current (3.3V ON) 150 100 50 1470/71 G03 1 2 3 4 5 5VIN SUPPLY VOLTAGE (V) 3.3V Switch Resistance TA = 25°C PROGRAMMED TO 5V, NO LOAD 250 200 150 100 0 6 0.30 50 6 0 1470/71 G01 3.3V SWITCH RESISTANCE (Ω) 5VIN SUPPLY CURRENT (µA) 200 2 3 4 5 5VIN SUPPLY VOLTAGE (V) 1 5VIN Supply Current (5V ON) TA = 25°C PROGRAMMED TO 3.3V, NO LOAD 1 2 –1 4 300 0 3 1470/71 G05 300 250 TA = 25°C PROGRAMMED TO OFF 4 0 0 3 1 2 3VIN SUPPLY VOLTAGE (V) 0 TA = 25°C PROGRAMMED TO 3.3V, NO LOAD 100 5VIN SUPPLY CURRENT (µA) TA = 25°C PROGRAMMED TO OFF 4 0 5VIN SUPPLY CURRENT (µA) 5VIN Supply Current (OFF) 5 120 3VIN SUPPLY CURRENT (µA) 3VIN SUPPLY CURRENT (µA) 5 0 (LTC1470 or 1/2 LTC1471) PROGRAMMED TO 3.3V 0.25 0.20 0.15 0.10 0.05 0 0 1 5 2 3 4 5VIN SUPPLY VOLTAGE (V) 6 1470/71 G02 0 25 50 75 100 JUNCTION TEMPERATURE (°C) 125 1470/71 G07 3 LTC1470/LTC1471 U W TYPICAL PERFORMANCE CHARACTERISTICS OUTPUT VOLTAGE (V) INRUSH CURRENT (A) 5V SWITCH RESISTANCE (Ω) PROGRAMMED TO 5V 0.20 0.15 0.10 0.05 0 0 25 50 75 100 JUNCTION TEMPERATURE (°C) 125 Inrush Current (5V Switch) 3 2 TJ = 25°C COUT = 150µF ROUT = 6.6Ω 1 0 COUT = 15µF ROUT = 6.6Ω 6 4 COUT = 150µF ROUT = 6.6Ω 2 0 – 0.2 0 0.2 0.4 0.6 0.8 TIME (ms) 1470/71 G06 1.0 1.2 1.4 OUTPUT VOLTAGE (V) INRUSH CURRENT (A) Inrush Current (3.3V Switch) 5V Switch Resistance 0.30 0.25 (LTC1470 or 1/2 LTC1471) 3 2 TJ = 25°C CURRENT LIMITED 1 0 COUT = 150µF ROUT = 10Ω COUT = 15µF ROUT = 10Ω 6 4 2 0 – 0.2 0 0.2 1470/71 G09 0.4 0.6 0.8 TIME (ms) 1.0 1.2 1.4 1470/71 G08 U U U PIN FUNCTIONS LTC1470 OUT (Pins 1, 8): Output Pins. The outputs of the LTC1470 are switched between three operating states: OFF, 3.3V and 5V. These pins are protected against accidental short circuits to ground by SafeSlot current limit circuitry which protects the socket, the card, and the system power supplies against damage. A second level of protection is provided by thermal shutdown circuitry which protects both switches against over-temperature conditions. 5VIN (Pin 2): 5V Input Supply Pin. 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 therefore be continuously powered. EN1, EN0 (Pins 3, 4): Enable Inputs. The two VCC Enable inputs are designed to interface directly with industry standard PCMCIA controllers and are high impedance CMOS gates with ESD protection diodes to ground, and 4 should not be forced below ground. Both inputs have about 100mV of built-in hysteresis to ensure clean switching between operating modes. The LTC1470 is designed to operate without 12V power. The gates of the VCC NMOS switches are powered by charge pumps from the 5VIN supply pins (see Applications Information section for more detail). The Enable inputs should be turned off (both asserted high or both asserted low) at least 100µs before the 5VIN power is removed to ensure that both VCC NMOS switch gates are fully discharged and both switches are in the high impedance mode. GND (Pin 5): Ground Connection. 3VIN (Pins 6, 7): 3V Input Supply Pins. The 3VIN supply pins serve as the power supply input for the 3.3V switches. These pins do not provide any power to the internal control circuitry and therefore do not consume any power when unloaded or turned off. LTC1470/LTC1471 U U U PIN FUNCTIONS LTC1471 AOUT, BOUT(Pins 1, 16, 8, 9): Output Pins. The outputs of the LTC1471 are switched between three operating states: OFF, 3.3V and 5V. These pins are protected against accidental short circuits to ground by SafeSlot current limit circuitry which protects the socket, the card, and the system power supplies against damage. A second level of protection is provided by thermal shutdown circuitry. 5VIN (Pins 2, 10): 5V Input Supply Pins. The 5VIN supply pins serve two purposes. The first purpose is as the power supply input for the 5V NMOS switches. The second purpose is to provide power for the input, gate drive, and protection circuitry. These pins must therefore be continuously powered. EN1, EN0 (Pins 3, 4, 11, 12): Enable Inputs. The enable inputs are designed to interface directly with industry standard PCMCIA controllers and are high impedance CMOS gates with ESD protection diodes to ground, and W BLOCK DIAGRAM should not be forced below ground. All four inputs have about 100mV of built-in hysteresis to ensure clean switching between operating modes. The LTC1471 is designed to operate without 12V power. The gates of the VCC NMOS switches are powered by charge pumps from the 5VIN supply pins (see Applications Information section for more detail). The enable inputs should be turned off at least 100µs before the 5VIN power is removed to ensure that all NMOS switch gates are fully discharged and are in the high impedance mode. GND (Pins 5, 13): Ground Connections. 3VIN (Pins 6, 7, 14, 15): 3V Input Supply Pins. The 3VIN supply pins serve as the power supply input for the 3.3V switches. These pins do not not provide any power to the internal control circuitry, and therefore, do not consume any power when unloaded or turned off. (LTC1470 or 1/2 LTC1471) 5VIN GATE CHARGE AND DISCHARGE CONTROL LOGIC EN0 EN1 TTL-TO-CMOS CONVERTER TTL-TO-CMOS CONVERTER BREAK-BEFOREMAKE SWITCH AND CONTROL OSCILLATOR AND BIAS CHARGE PUMP GATE CHARGE AND DISCHARGE CONTROL LOGIC 0.14Ω CURRENT LIMIT AND THERMAL SHUTDOWN OUTPUT 0.12Ω 3VIN LTC1470-BD01 5 LTC1470/LTC1471 U OPERATION The LTC1470 (or 1/2 of the LTC1471) consists of the following functional blocks: on slowly (400µs typical rise time) but turns them off much more quickly (typically 10µs). Input TTL/CMOS Converters Bias, Oscillator and Gate Charge Pump The enable 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 5V supply. Therefore, when the inputs are turned off, the entire circuit is powered down and the 5V supply current drops below 1µA. When either the 3.3V or 5V switch is enabled, a bias current generator and high frequency oscillator are turned on. The 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. XOR Input Circuitry Gate Charge and Discharge Control 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, there is no danger of both switches being on at the same time. This XOR function also makes it possible to work with either active -low or active-high PCMCIA VCC switch control logic (see Applications Information section for further details). All 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 5V power supply. Switch Protection Break-Before-Make Switch Control Built-in delays are provided to ensure that the 3.3V and 5V switches are non-overlapping. Further, the gate charge pump includes circuitry which ramps the NMOS switches Both switches are protected against accidental short circuits with SafeSlot foldback current limit circuits which limit the output current to typically 1A when the output is shorted to ground. Both switches also have thermal shutdown which limits the power dissipation to safe levels. U W U U APPLICATIONS INFORMATION The LTC1470/LTC1471 are designed to interface directly with industry standard PCMCIA card controllers. 3.3V 0.1µF 3VIN Interfacing with the CL-PD6710 5V 3VIN 5VIN 0.1µF Figure 1 is a schematic diagram showing the LTC1470 interfaced with a standard PCMCIA slot controller. The LTC1470 accepts logic control directly from the CL-PD6710. The XOR input function allows the LTC1470 to interface directly to the active-low VCC control outputs of the CLPD6710 for 3.3V/5V voltage selection (see the following Switch Truth Table). Therefore, no “glue” logic is required to interface to this PCMCIA compatible card controller. 6 CL-PD6710 LTC1470 VCC _3 EN0 OUT VCC _5 EN1 OUT GND (OFF/3.3V/5V) + 1µF TANT TO CARD VCC PINS 10k 1470/71 F01 Figure 1. Direct Interface to CL-PD6710 PCMCIA Controller LTC1470/LTC1471 U U W U APPLICATIONS INFORMATION Truth Table for CL-PD6710 Controller A_VCC _3 A_VCC _5 EN0 EN1 OUT 0 0 Hi-Z 0 1 3.3V 1 0 5V 1 1 Hi-Z Supply Bypassing For best results bypass the supply input pins with 1µF capacitors as close as possible to the LTC1470. Sometimes much larger capacitors are already available at the outputs of the 3.3V and 5V power supply. In this case it is still good practice to use 0.1µF capacitors as close as possible to the device, especially if the power supply output capacitors are more than 2" away on the printed circuit board. Interfacing with “365” Type Controllers The LTC1470 also interfaces directly with “365” type controllers as shown in Figure 2. Note that the VCC Enable inputs are connected differently than to the CL-PD6710 controller because the “365” type controllers use activehigh logic control of the VCC switches (see the following Switch Truth Table). No “glue” logic is required to interface to this type of PCMCIA compatible controller. 3.3V 5V 3VIN 5VIN 0.1µF “365” TYPE CONTROLLER The output 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 3VIN or 5VIN supply pins (see graphs in Typical Performance Characteristics section). The output pin should have a 0.1µF to 1µF capacitor for noise reduction and smoothing. A 10k pull-down resistor is recommended at the output to ensure that the output capacitor is fully discharged when the output is switched OFF. This resistor also ensures that the output is discharged between the 3.3V and 5V transition. 0.1µF 3VIN Output Capacitors and Pull-Down Resistor LTC1470 A_VCC _EN0 A_VCC _EN1 Supply Sequencing OUT EN0 OUT EN1 GND (OFF/3.3V/5V) + 1µF TANT TO CARD VCC PINS 10k 1470/71 F02 Figure 2. Direct Interface with “365” Type PCMCIA Controller Truth Table for “365” Type Controller A_VCC _EN0 A_VCC_EN1 EN0 EN1 OUT 0 0 Hi-Z 0 1 3.3V 1 0 5V 1 1 Hi-Z Because the 5V supply is the source of power for both of the switch control circuits, it is best to sequence the power supplies such that the 5V supply is powered before, or simultaneous to, the application of 3.3V. It is interesting to note, however, that the switches are NMOS transistors which require charge pumps to generate gate voltages higher than the supply rails for full enhancement. Because the gate voltages start at 0V when the supplies are first activated, the switches always start in the off state and do not produce glitches at the outputs when powered. 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 the NMOS switch gates are fully discharged to 0V. Whenever possible, however, it is best to leave the 5VIN pin(s) continuously powered. The LTC1470/LTC1471 quiescent current drops to <1µA with all the switches turned off and therefore no 5V power is consumed in the standby mode. 7 LTC1470/LTC1471 U U W U APPLICATIONS INFORMATION TOTAL SYSTEM COST CONSIDERATIONS LTC1142HV Auxiliary Winding Power Supply The cost of an additional step-up switching regulator, inductor, rectifier and capacitors to produce 12V for VPP can be eliminated by using an auxiliary winding on either the 3.3V or 5V output of the system switching regulator to produce an auxiliary 15V supply for VPP power. Figure 3 is a schematic diagram which describes how a loosely regulated 15V power supply is created by adding an auxiliary winding to the 5V inductor in a split 3.3V/5V LTC1142HV power supply system. An LT1313, dual VPP regulator/driver with SafeSlot protection, produces “clean” 3.3V, 5V and 12V power from this loosely regulated 15V output for the PC card slot VPP pins. (See LT1312 and LT1313 data sheets for further detail.) And, because the LTC1470/LTC1471 do not require 12V power to operate (only 5V), the 12V VPP regulation and switching may be operated separately from the 3.3V/5V VCC switching. This increases system configuration flexibility and reduces total system cost by eliminating the need for a third regulator for 12V power. VIN 6.5V TO 18V VIN PDRIVE 1/2 LTC1142HV (5V REG) NDRIVE SENSE + D1 MBRS140 + 9 C1 68µF R4 22Ω C4 1000pF 20 Q2 15 14 Q3 2N7002 D3 MBRS130T3 T1* R1 30µH 100Ω 1.8:1 D2 MBRS140 + AEN0 AVPPEN1 AEN1 AVPPOUT TO “A” SLOT VPP PINS + 1µF AVALID LT1313 C5 22µF R5 0.033Ω R2 100Ω AVPPEN0 AVALID + VS VS Q1 R3 18k AVPPEN0 (15V) 10 C2 1000pF SENSE – A turns ratio of 1:1.8 is used for transformer T1 to ensure that the input voltage to the LT1313 falls between 13V and 20V under all load conditions. The 9V output from this additional 5V OUTPUT BVPPEN0 BEN0 ASENSE BVPPEN1 BEN1 BVPPOUT BVALID FROM “A” VCC PINS 1µF BVALID C3 220µF GND TO “B” SLOT VPP PINS + BSENSE GND FROM “B” VCC PINS Q4 2N7002 BVPPEN0 3.3V 0.1µF A3VIN A3VIN B3VIN B3VIN * LPE-6562-A026 DALE (605) 665-9301 5V 0.1µF A5VIN BOUT B5VIN BOUT + LTC1471 AVCCEN0 AEN0 AVCCEN1 AEN1 BVCCEN0 BEN0 BVCCEN1 BEN1 1µF TANT TO “A” SLOT VCC PINS 10k AOUT GND GND AOUT + 1µF TANT 10k TO “B” SLOT VCC PINS 1470/71 F03 Figure 3. Cost Effective Complete SafeSlot Dual PCMCIA Power Management System (with 15V Auxiliary Supply from LTC1142HV 5V Regulator Inductor) 8 LTC1470/LTC1471 U W U U APPLICATIONS INFORMATION winding is rectified by diode D2, added to the main 5V output and applied to the input of the LT1313. (Note that the auxiliary winding must be phased properly as shown in Figure 3.) When the 12V output is activated by a TTL high on either VPP enable lines, the 5V section of the LTC1142HV is forced into continuous mode operation. A resistor divider composed of R2, R3 and switch Q3 forces an offset which is subtracted from the internal offset at the Sense– input (pin 14) of the LTC1142HV. When this external offset cancels the built-in 25mV offset, Burst ModeTM operation is inhibited and the LTC1142HV is forced into continuous mode operation. (See LTC1142HV data sheet for further detail.) In this mode, the 15V auxiliary supply can be loaded without regard to the loading on the 5V output of the LTC1142HV. Continuous mode operation is only invoked when the LT1313 is programmed to 12V. If the LT1313 is programmed to 0V, 3.3V or 5V, power is obtained directly from the main power source (battery pack) through diode D1. Again, the LT1313 output can be loaded without regard to the loading of the main 5V output. R4 and C4 absorb transient voltage spikes associated with the leakage inductance inherent in T1’s secondary winding and ensure that the auxiliary supply does not exceed 20V. Auxiliary Power from the LTC1142 3.3V Output For low-battery count applications (< 6.5V) it is necessary to modify the circuit of Figure 3. As the input voltage falls, the 5V duty cycle increases to the point where there is simply not enough time to transfer energy from the 5V primary winding to the auxiliary winding. For applications where 12V load currents exist in conjunction with these low input voltages, use the circuit shown in Figure 4. In this circuit, the auxiliary 15V supply is generated from an overwinding on the 3.3V inductor of the LTC1142 regulator output. In Figure 3, power is drawn directly from the batteries through D1 when the regulator is in Burst Mode operation and the VPP pins require 3.3V or 5V. In this circuit, however, Q3 and Q4 force the LTC1142 3.3V regulator into continuous mode operation whenever 3.3V, 5V or 12V is programmed at the VPPOUT pins of the LT1313. (See the LT1312 and LT1313 data sheets for further detail.) Burst Mode is a trademark of Linear Technology Corporation. VIN 5.4V TO 11V VIN PDRIVE 24 + 23 C1 68µF D2 MBRS1100 Q1 15V AUX SUPPLY 1/2 LTC1142 (3.3V REG) NDRIVE 6 Q2 C2 1000pF D4 18V 28 + HC86 + C5 68µF R4 0.033Ω R2 100Ω R3 12k AENVPP0 AENVPP1 3.37:1 100Ω 1 SENSE + SENSE – D3 MBRS130T3 T1* 15µH R1 3.3V OUTPUT C3 220µF Q3 2N7002 HC86 BENVPP0 BENVPP1 Q4 2N7002 *CTX02-12753 COILTRONICS (407) 241-7876 1470/71 F04 Figure 4. Deriving 15V from the 3.3V Output of the LTC1142 for VPP Power 9 LTC1470/LTC1471 U TYPICAL APPLICATIONS Dual Slot 3.3V/5V PCMCIA Controller with SafeSlot Current Limit (Systems with No 12V Power Requirements) 3.3V 0.1µF A3VIN A3VIN B3VIN B3VIN 5V 0.1µF A5VIN BOUT B5VIN BOUT CL-PD6710 VCC (OFF/3.3V/5V) + LTC1471 A_VCC _3 AEN0 A_VCC _5 AEN1 B_VCC _3 BEN0 B_VCC _5 BEN1 1µF TANT VCC PCMCIA CARD SLOT 10k VCC AOUT (OFF/3.3V/5V) GND GND AOUT + 1µF TANT VCC PCMCIA CARD SLOT 10k 1470/71 TA02 Single Slot PCMCIA Controller with SafeSlot Current Limit Protection Using LT1312 Single VPP Regulator/Driver VLOGIC 13V TO 20V* 51k VCC VPP_PGM VS EN0 VPPOUT VPP2 PCMCIA CARD SLOT VCC SENSE VALID VPP_VALID 1µF LT1312 EN1 VPP_VCC VPP1 + GND CIRRUS LOGIC CL-PD6710 3.3V 0.1µF 3VIN 5VIN 5V 3VIN 10k 0.1µF LTC1470 VCC _5 EN0 VCC _3 EN1 0UT 0UT GND * FROM OVERWINDING ON 3.3V OR 5V INDUCTOR IN SYSTEM POWER SUPPLY. SEE FIGURES 3, 4 FOR FURTHER DETAIL 10 + 1µF TANT 1470/71 TA03 LTC1470/LTC1471 U TYPICAL APPLICATIONS Dual Slot PCMCIA Controller with SafeSlot Current Limit Protection Using LT1313 Dual VPP Regulator/Driver VLOGIC 13V TO 20V* 0.1µF 51k A_VPP_PGM AEN0 A_VPP_VCC VPP1 BVS AVS AVPPOUT VPP2 PCMCIA CARD SLOT #1 + 1µF AEN1 AVALID VCC ASENSE VPP1 LT1313 B_VPP_PGM BVPPOUT BEN0 VPP2 PCMCIA CARD SLOT #2 + 1µF B_VPP_VCC BEN1 VPP_VALID BVALID VCC BSENSE GND GND CL-PD6720 3.3V 0.1µF A3VIN A3VIN B3VIN B3VIN 5V 0.1µF A5VIN BOUT B5VIN BOUT (OFF/3.3V/5V) + LTC1471 A_VCC _3V AEN0 A_VCC _5V AEN1 B_VCC _3V BEN0 B_VCC _5V BEN1 1µF TANT 10k AOUT (OFF/3.3V/5V) GND GND AOUT + 1µF TANT 10k * FROM OVERWINDING ON 3.3V OR 5V INDUCTOR IN SYSTEM POWER SUPPLY. SEE FIGURES 3, 4 FOR FURTHER DETAILS 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. 1470/71 TA04 11 LTC1470/LTC1471 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic SOIC 0.010 – 0.020 × 45° (0.254 – 0.508) 6 5 0.004 – 0.010 (0.101 – 0.254) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 7 8 0.053 – 0.069 (1.346 – 1.752) 0.008 – 0.010 (0.203 – 0.254) 0.189 – 0.197* (4.801 – 5.004) *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006 INCH (0.15mm). 0.150 – 0.157* (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 0.050 (1.270) BSC 0.014 – 0.019 (0.355 – 0.483) 1 3 2 4 SO8 0294 S Package 16-Lead Plastic SOIC 0.386 – 0.394* (9.804 – 10.008) 16 15 14 13 12 11 10 9 0.150 – 0.157* (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 2 3 4 5 6 7 8 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0° – 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP SO16 0893 *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. 12 Linear Technology Corporation LT/GP 0495 10K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 ● FAX: (408) 434-0507 ● TELEX: 499-3977 LINEAR TECHNOLOGY CORPORATION 1995