LT1312CS8

LT1312 Single PCMCIA VPP Driver/Regulator FEATURES s s s s s s s s s s s DESCRIPTION The LT ® 1312 is a member of Linear Technology Corporation’s family of PCMCIA drivers/regulators. The LT1312 provides 0V, 3.3V, 5V, 12V and Hi-Z regulated power to the VPP pin of a PCMCIA card slot from a single unregulated 13V to 20V supply. When used in conjunction with a PC card interface controller, the LT1312 forms a complete minimum component-count interface for palmtop, pen-based and notebook computers. The VPP output voltage is selected by two logic compatible digital inputs which interface directly with industry standard PC card interface controllers. Automatic 3.3V to 5V switching is provided by an internal comparator which continuously monitors the PC card VCC supply and automatically adjusts the regulated VPP output to match VCC when the VPP = VCC mode is selected. An open-collector VPP VALID output is driven low when VPP is in regulation at 12V. The LT1312 is available in an 8-pin SO package. , LTC and LT are registered trademarks of Linear Technology Corporation. Digital Selection of 0V, VCC, 12V or Hi-Z 120mA Output Current Capability Internal Current Limiting and Thermal Shutdown Automatic Switching from 3.3V to 5V Powered from Unregulated 13V to 20V Supply Logic Compatible with Standard PCMCIA Controllers 1µF Output Capacitor 30µA Quiescent Current in Hi-Z or 0V Mode VPP Valid Status Feedback Signal No VPP Overshoot 8-Pin SO Packaging APPLICATIONS s s s s s s Notebook Computers Palmtop Computers Pen-Based Computers Handi-Terminals Bar-Code Readers Flash Memory Programming TYPICAL APPLICATION Typical PCMCIA Single Slot VPP Driver 13V TO 20V VS PCMCIA CARD SLOT CONTROLLER EN0 VPPOUT VPP1 VPP2 PCMCIA CARD SLOT VCC 3.3V OR 5V Linear Technology PCMCIA Product Family DEVICE LT1312 LT1313 LT1312 TA1 DESCRIPTION SINGLE PCMCIA VPP DRIVER/REGULATOR DUAL PCMCIA VPP DRIVER/REGULATOR DUAL PCMCIA SWITCH MATRIX PROTECTED VCC 5V/3.3V SWITCH MATRIX EN1 LT1312 VALID SENSE GND + COUT 1µF TANTALUM LTC 1314 SINGLE PCMCIA SWITCH MATRIX LTC1315 LTC1470 LTC1472 ® LT1312 TRUTH TABLE EN0 EN1 0 0 1 0 0 1 0 1 1 1 X = DON’T CARE SENSE X X 3.0V TO 3.6V 4.5V TO 5.5V X VPPOUT 0V 12V 3.3V 5V Hi-Z VALID 1 0 1 1 1 PROTECTED VCC AND VPP SWITCH MATRIX 16-PIN SO* *NARROW BODY U U U PACKAGE 8-PIN SO 16-PIN SO* 14-PIN SO 24-PIN SSOP 8-PIN SO 1 LT1312 ABSOLUTE MAXIMUM RATINGS Supply Voltage ........................................................ 22V Digital Input Voltage ........................ 7V to (GND – 0.3V) Sense Input Voltage ......................... 7V to (GND – 0.3V) Valid Output Voltage ...................... 15V to (GND – 0.3V) Output Short-Circuit Duration .......................... Indefinite Operating Temperature ................................ 0°C to 70°C Junction Temperature................................ 0°C to 125°C Storage Temperature Range ................. –65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C PACKAGE/ORDER INFORMATION TOP VIEW GND 1 ENO 2 EN1 3 VALID 4 8 7 6 5 VPPOUT N.C. VS SENSE ORDER PART NUMBER LT1312CS8 S8 PART MARKING 1312 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 125°C, θJA = 150°C/ W Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS SYMBOL VPPOUT PARAMETER Output Voltage CONDITIONS VS = 13V to 20V, TA = 25°C, unless otherwise noted. MIN q q q q q q q q q q q q TYP 12.00 5.00 3.30 0.42 30 30 230 75 55 126 31 31 330 MAX 12.48 5.25 3.465 0.60 10 50 50 360 120 90 132 33 33 500 0.4 UNITS V V V V µA µA µA µA µA µA mA mA mA mA V V µA µA V V µA µA V mA µA Program to 12V, IOUT ≤ 120mA (Note 1) Program to 5V, IOUT ≤ 30mA (Note 1) Program to 3.3V, IOUT ≤ 30mA (Note 1) Program to 0V, IOUT = – 300µA Program to Hi-Z, 0V ≤ VPPOUT ≤ 12V Program to 0V Program to Hi-Z Program to 12V, No Load Program to 5V, No Load Program to 3.3V, No Load Program to 12V, IOUT = 120mA Program to 5V, IOUT = 30mA Program to 3.3V, IOUT = 30mA Program to 3.3V, 5V or 12V 11.52 4.75 3.135 – 10 ILKG IS Output Leakage Supply Current ILIM VENH VENL IENH IENL VSEN5 VSEN3 ISEN VVALID TH IVALID Current Limit Enable Input High Voltage Enable Input Low Voltage Enable Input High Current Enable Input Low Current VCC Sense Threshold VCC Sense Threshold VCC Sense Input Current VPP VALID Threshold Voltage VPP VALID Output Drive Current VPP VALID Output Leakage Current q q 2.4 20 0.01 50 1 4.50 4.50 60 30 11.5 10 2.4V ≤ VIN ≤ 5.5V 0V ≤ VIN ≤ 0.4V VPPOUT = 3.3V to 5V VPPOUT = 5V to 3.3V VSENSE = 5V VSENSE = 3.3V Program to 12V Program to 12V, VVALID = 0.4V Program to 0V, VVALID = 12V q q q 3.60 3.60 4.05 4.00 38 18 10.5 1 11 3.3 0.1 The q denotes the specifications which apply over the full operating temperature range. Note 1: For junction temperatures greater than 110°C, a minimum load of 1mA is recommended. 2 U W U U WW W LT1312 TYPICAL PERFORMANCE CHARACTERISTICS Quiescent Current (0V or Hi-Z Mode) 50 TJ = 25°C EN0 = EN1= 0V OR EN0 = EN1= 5V 500 TJ = 25°C EN0 = 5V EN1 = 0V RL = ∞ QUIESCENT CURRENT (µA) QUIESCENT CURRENT (µA) 30 300 QUIESCENT CURRENT (µA) 40 20 10 0 0 5 15 20 10 SUPPLY VOLTAGE (V) Ground Pin Current (12V Mode) 10 TJ = 25°C EN0 = 5V EN1 = 0V RL = 100Ω IL = 120mA* 2.5 GROUND CURRENT (mA) GROUND CURRENT (mA) 6 RL = 200Ω IL = 60mA* RL = 400Ω IL = 30mA* *FOR VPPOUT = 12V 0 5 15 20 10 SUPPLY VOLTAGE (V) 25 LT1312 G4 1.5 RL = 167Ω IL = 30mA* 1.0 RL = 500Ω IL = 10mA* *FOR VPPOUT = 5V 0 5 15 20 10 SUPPLY VOLTAGE (V) 25 LT1312 G5 GROUND CURRENT (mA) 8 4 2 0 Ground Pin Current 16 800 SHORT-CIRCUIT CURRENT (mA) 12 10 8 6 4 2 0 0 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) LT1312 G7 600 500 400 300 200 100 0 0 5 15 INPUT VOLTAGE (V) 10 20 25 LT1312 G8 SHORT-CIRCUIT CURRENT (mA) 14 GROUND PIN CURRENT (mA) TJ = 25°C VS = 15V UW LT1312 G1 Quiescent Current (12V Mode) 250 Quiescent Current (3.3V/5V Mode) TJ = 25°C EN0 = 0V EN1 = 5V RL = ∞ 400 200 150 200 100 VSENSE = 5V VSENSE = 3.3V 100 50 25 0 0 5 15 20 10 SUPPLY VOLTAGE (V) 25 LT1312 G2 0 0 5 15 20 10 SUPPLY VOLTAGE (V) 25 LT1312 G3 Ground Pin Current (5V Mode) 2.5 TJ = 25°C EN0 = 0V EN1 = 5V VSENSE = 5V Ground Pin Current (3.3V Mode) TJ = 25°C EN0 = 0V EN1 = 5V VSENSE = 3.3V 2.0 2.0 1.5 RL = 110Ω IL = 30mA* 1.0 RL = 330Ω IL = 10mA* *FOR VPPOUT = 3.3V 0 5 15 20 10 SUPPLY VOLTAGE (V) 25 LT1312 G6 0.5 0.5 0 0 Current Limit 600 TJ = 25°C VPPOUT = 0V 700 Current Limit VS = 15V VPPOUT = 0V 500 400 300 200 100 0 0 25 50 75 100 JUNCTION TEMPERATURE (°C) 125 LT1312 G9 3 LT1312 TYPICAL PERFORMANCE CHARACTERISTICS Enable Input Threshold Voltage 3.0 VS = 15V ENABLE INPUT CURRENT (µA) 2.5 2.0 1.5 1.0 0.5 0 0 25 50 75 100 JUNCTION TEMPERATURE (°C) 125 LT1312 G10 VCC SENSE THRESHOLD VOLTAGES (V) INPUT THRESHOLD VOLTAGE (V) VCC Sense Input Current 50 VCC SENSE INPUT CURRENT (µA) TJ = 25°C VS = 15V VALID OUTPUT VOLTAGE (V) RIPPLE REJECTION RATIO (dB) 40 30 20 10 0 0 1 5 2 3 4 ENABLE INPUT VOLTAGE (V) 12V Turn-On Waveform OUTPUT VOLTAGE (V) OUTPUT VOLTAGE CHANGE (mV) 12.4 12.2 12.0 11.8 11.6 COUT = 1µF COUT = 10µF VS = 15V 20 0 –20 –40 COUT = 1µF OUTPUT VOLTAGE CHANGE (V) 5 0 –0.2 0 0.2 0.4 0.6 TIME (ms) 0.8 1.0 1.2 15 13 –0.1 0 0.1 0.2 0.3 TIME (ms) 0.4 0.5 0.6 LOAD CURRENT (mA) EN0 INPUT (V) SUPPLY VOLTAGE (V) 4 UW 6 LT1312 G13 LT1312 G16 Enable Input Current 50 TJ = 25°C VS = 15V VCC Sense Threshold Voltage 5.5 5.0 4.5 4.0 SWITCH TO 3.3V 3.5 3.0 2.5 0 25 50 75 100 JUNCTION TEMPERATURE (°C) 125 LT1312 G12 TJ = 25°C VS = 15V 40 SWITCH TO 5V 30 20 10 0 0 1 5 2 3 4 ENABLE INPUT VOLTAGE (V) 6 LT1312 G11 VALID Output Voltage 1.0 100 TJ = 25°C VS = 15V EN0 = 5V EN1 = 0V Ripple Rejection (12V) TJ = 25°C, 12V MODE VS = 15V + 100mVRMS RIPPLE 80 0.8 0.6 60 COUT = 1µF TANTALUM 0.4 40 0.2 20 0 0 2.5 1.0 1.5 2.0 0.5 VALID OUTPUT CURRENT (mA) 3.0 0 10 100 1k 10k FREQUENCY (Hz) 100k 1M LT1312 G14 LT1312 G15 Line Transient Response (12V) 40 0.4 0.2 0 –0.2 –0.4 Load Transient Response (12V) COUT = 1µF COUT = 10µF COUT = 10µF 100 50 –0.1 0 0.1 0.2 0.3 TIME (ms) 0.4 0.5 0.6 LT1312 G17 LT1312 G18 LT1312 PIN FUNCTIONS Supply Pin: Power is supplied to the device through the supply pin. The supply pin should be bypassed to ground if the device is more than 6 inches away from the main supply capacitor. A bypass capacitor in the range of 0.1µF to 1µF is sufficient. The supply voltage to the LT1312 can be loosely regulated between 13V and 20V. See Applications Information section for more detail. VPPOUT Pin: This regulated output supplies power to the PCMCIA card VPP pins which are typically tied together at the card socket. The VPPOUT output is current limited to approximately 330mA. Thermal shutdown provides a second level of protection. A 1µF to 10µF tantalum output capacitor is recommended. See Applications Information section for more detail on output capacitor considerations. Input Enable Pins: The two digital input pins are high impedance inputs with approximately 20µA input current at 2.4V. The input thresholds are compatible with CMOS controllers and can be driven from either 5V or 3.3V CMOS logic. ESD protection diodes limit input excursions to 0.6V below ground. VALID Output Pin: This pin is an open-collector NPN output which is driven low when the VPPOUT pin is in regulation, i.e., when it is above 11V. An external 51k pullup resistor is connected between this output and the same 5V or 3.3V logic supply powering the PCMCIA compatible control logic. VCC Sense Pin: A built-in comparator and 4V reference automatically switches the VPPOUT from 5V to 3.3V depending upon the voltage sensed at the PCMCIA card socket VCC pin. The input current for this pin is approximately 30µA. For 5V only operation, connect the Sense pin directly to ground. An ESD protection diode limits the input voltage to 0.6V below ground. BLOCK DIAGRAM VS VCC SENSE 4V EN0 EN1 11V VOLTAGE LOGIC CONTROL W U U U LOW DROPOUT LINEAR REGULATOR VPPOUT + – + – VALID LT1312 BD 5 LT1312 OPERATION The LT1312 is a programmable output voltage, lowdropout linear regulator designed specifically for PCMCIA VPP drive applications. Input power is typically obtained from a loosely regulated input supply between 13V and 20V (see Applications Information section for more detail on the input power supply). The LT1312 consists of the following blocks: Low Dropout Voltage Linear Regulator: The heart of the LT1312 is a PNP-based low-dropout voltage regulator which drops the unregulated supply voltage from 13V to 20V down to 12V, 5V, 3.3V, 0V or Hi-Z depending upon the state of the two Enable inputs and the VCC Sense input. The regulator has built-in current limiting and thermal shutdown to protect the device, the load, and the socket against inadvertent short circuiting to ground. Voltage Control Logic: The LT1312 has five possible output modes: 0V, 3.3V, 5V, 12V and Hi-Z. These five modes are selected by the two Enable inputs and the VCC Sense input as described by the Truth Table. VCC Sense Comparator: When the VCC mode is selected, the LT1312 automatically adjusts the regulated VPP output voltage to 3.3V or 5V depending upon the voltage present at the PC card VCC supply pin. The threshold voltage for the comparator is set at 4V and there is approximately 50mV of hysteresis provided to ensure clean switching between 3.3V and 5V. VPP VALID Comparator: A voltage comparator monitors the output voltage when the 12V mode is selected and is driven low when the output is in regulation above 11V. APPLICATIONS INFORMATION The LT1312 is a voltage programmable linear regulator designed specifically for PCMCIA VPP driver applications. The device operates with very low quiescent current (30µA) in the 0V and Hi-Z modes of operation. In the Hi-Z mode, the output leakage current falls to 1µA. Unloaded quiescent current rises to only 55µA and 75µA when programmed to 3.3V and 5V respectively. In addition to the low quiescent currents, the LT1312 incorporates several protection features which make it ideal for PCMCIA applications. The LT1312 has built-in current limiting (330mA) and thermal shutdown to protect the device and the socket VPP pins against inadvertent short-circuit conditions. AUXILIARY WINDING POWER SUPPLIES Because the LT1312 provides excellent output regulation, the input power supply may be loosely regulated. One convenient (and economic) source of power is an auxiliary winding on the main 5V switching regulator inductor in the main system power supply. LTC®1142HV Auxiliary Winding Power Supply Figure 1 is a schematic diagram which describes how a loosely regulated 14V power supply is created by adding an auxiliary winding to the 5V inductor in a split 3.3V/5V LTC1142HV power supply system. A turns ratio of 1:1.8 is used for transformer T1 to ensure that the input voltage to the LT1312 falls between 13V and 20V under all load conditions. The 9V output from this additional winding is rectified by diode D2, added to the main 5V output and applied to the input of the LT1312. (Note that the auxiliary winding must be phased properly as shown in Figure 1.) The auxiliary winding is referenced to the 5V output which provides DC current feedback from the auxiliary supply to the main 5V section. The AC transient response is improved by returning the negative lead of C5 to the 5V output as shown. When the 12V output is activated by a TTL high on the Enable line, 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 the LTC1142HV data sheet for further detail). In this mode, the 14V auxiliary supply can be Burst Mode is a trademark of Linear Technology Corporation. 6 U W U U U LT1312 APPLICATIONS INFORMATION VIN 10 VIN 6.5V TO 18V D1 MBRS140 + 9 Q1 C1 68µF PDRIVE 1/2 LTC1142HV 20 NDRIVE 5V REG Q2 D3 MBRS130T3 R1 100Ω 15 SENSE+ C2 1000pF 14 SENSE– R3 18k Q3 VN7002 R2 100Ω R5 0.033Ω + C3 220µF EN0 EN1 VALID *LPE-6562-A026 DALE (605) 665-9301 Figure 1. Deriving 14V Power from an Auxiliary Winding on the LTC1142HV 5V Regulator loaded without regard to the loading on the 5V output of the LTC1142HV. Continuous mode operation is only invoked when the LT1312 is programmed to 12V. If the LT1312 is programmed to 0V, 3.3V or 5V, power is obtained directly from the main power source (battery pack) through diode D1. Again, the LT1312 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. Figure 2 is a graph of output voltage versus output current for the auxiliary 14V supply shown in Figure 1. Note that the auxiliary supply voltage is slightly higher when the 5V output is heavily loaded. This is due to the increased energy flowing through the main 5V inductor. LTC1142 Auxiliary Power from the 3.3V Output The circuit of Figure 1 can be modified for operation with low-battery count applications (6 cell). As the input voltage falls, the 5V duty cycle increases to the point where AUXILIARY OUTPUT VOLTAGE (V) U W U U R4 22Ω C4 1000pF D2 MBRS140 14V AUXILIARY SUPPLY T1 1.8T 30µH* + C5 22µF EN0 5V OUTPUT VS VPPOUT TO CARD VPP PIN 0V, 3.3V, 5V, 12V OR HI-Z EN1 LT1312 VALID SENSE GND + 1µF FROM CARD VCC PIN LT1312 F1 there is simply not enough time to transfer energy from the 5V primary to the auxiliary winding. For applications where heavy 12V load currents exist in conjunction with low input voltages (1µF TANTALUM OR ALUMINUM Figure 6. Recommended >1µF Tantalum Output Capacitor 13V TO 20V 0.1µF EN0 VS VPPOUT 2Ω 0.33µF CERAMIC LT1312 F7 EN1 LT1312 VALID SENSE GND Figure 7. Using a 0.33µF to 1µF Output Capacitor 9 LT1312 APPLICATIONS INFORMATION Transient and Switching Performance The LT1312 is designed to produce minimal overshoot with capacitors in the range of 1µF to 10µF. Larger capacitor values can be used with a slowing of rise and fall times. The positive output slew rate is determined by the 330mA current limit and the output capacitor. The rise time for a 0V to 12V transition is approximately 40µs, the rise time for a 10µF capacitor is roughly 400µs (see the Transient Response curves in the Typical Performance Characteristics section). The fall time from 12V to 0V is set by the output capacitor and an internal pull-down current source which sinks about 30mA. This source will fully discharge a 1µF capacitor in less than 1ms. Thermal Considerations Power dissipated by the device is the sum of two components: output current multiplied by the input-output differential voltage IOUT × (VIN – VOUT), and ground pin current multiplied by supply voltage IGND × VIN. The ground pin current can be found by examining the Ground Pin Current curves in the Typical Performance Characteristics section. Heat sinking, for surface mounted devices, is accomplished by using the heat spreading capabilities of the PC board and its copper traces. The junction temperature of the LT1312 must be limited to 125°C to ensure proper operation. Use Table 1 in conjunction with the typical performance graphs, to calculate the power dissipation and die temperature for a particular application and ensure that the die temperature does not exceed 125°C under any operating conditions. Table 1. S8 Package* COPPER AREA TOPSIDE BACKSIDE 2500 sq mm 1000 sq mm 225 sq mm 1000 sq mm 2500 sq mm 2500 sq mm 2500 sq mm 1000 sq mm THERMAL RESISTANCE BOARD AREA (JUNCTION-TO-AMBIENT) 2500 sq mm 2500 sq mm 2500 sq mm 1000 sq mm 120°C/W 120°C/W 125°C/W 131°C/W 10 U W U U *Device is mounted topside. Calculating Junction Temperature Example: given an output voltage of 12V, an input supply voltage of 14V, an output current of 100mA, and a maximum ambient temperature of 50°C, what will the maximum junction temperature be? Power dissipated by the device will be equal to: IOUT × (VS – VPPOUT) + (IGND × VIN) where: IOUT = 100mA VIN = 14V IGND at (IOUT = 100mA, VIN = 14V) = 5mA so, PD = 100mA × (14V – 12V) + (5mA × 15V) = 0.275W Using Table 1, the thermal resistance will be in the range of 120°C/W to 131°C/W depending upon the copper area. So the junction temperature rise above ambient will be less than or equal to: 0.275W × 131°C/W = 36°C The maximum junction temperature will then be equal to the junction temperature rise above ambient plus the maximum ambient temperature or: TJMAX = 50°C + 36°C = 86°C. LT1312 TYPICAL APPLICATIONS Single Slot Interface to CL-PD6710 VLOGIC 51K EN0 13V TO 20V VS VPPOUT VCC A_VPP_PGM A_VPP_VCC VPP_VALID CIRRUS LOGIC CL-PD6710 5V Si9430DY OR MMSF3P02HD 3.3V OR 5V A_VCC_5 A_VCC_3 Si9933DY OR MMDF2P01HD VLOGIC 51k VCC A_VPP_EN0 A_VPP_EN1 A:GPI “365” TYPE CONTROLLER 5V VS A_VCC_EN0 IN1 G1 A_VCC_EN1 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 its circuits as described herein will not infringe on existing patent rights. U + VPP1 1µF VPP2 PCMCIA CARD SLOT VCC EN1 LT1312 VALID SENSE GND + 10 µF 3.3V LT1312 TA2 Single Slot Interface to “365” Type Controller 13V TO 20V VS VPPOUT VPP1 VPP2 PCMCIA CARD SLOT 3.3V OR 5V VALID SENSE GND VCC EN0 EN1 LT1312 + 1µF Si9410DY OR MMSF5N02HD LTC1157CS8 + IN2 GND G2 Si9956DY OR MMDF3N02HD 10µF 3.3V LT1312 TA3 11 LT1312 PACKAGE DESCRIPTION U Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic SOIC 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157* (3.810 – 3.988) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0°– 8° TYP 2 3 4 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) BSC SO8 0294 *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. 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7487 (408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977 LT/GP 0894 10K • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1994