LT1026 Voltage Converter U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT ® 1026 is a switched capacitor voltage doubler and inverter on a single monolithic die. Capable of operating from a 4V to 10V input, it provides ±7V to ±18V output. Output currents of over 10mA are available. Two charge pumps first double the input voltage then invert the doubled voltage. Manufactured in bipolar technology, the LT1026 is not susceptible to latchup and generates up to 36V. Generates + and – from Single Input Up to ±18V Output Only Needs Four 1µF Capacitors No Inductors 10mA Output Current Minimum Operates Down to 4V No Latchup 8-Pin Minidip U APPLICATIO S ■ ■ ■ Line Drivers Op Amp Suppliers Battery Splitters RS232 Power , LTC and LT are registered trademarks of Linear Technology Corporation. U ■ The LT1026 offers a convenient way of generating additional system voltages without using inductors. Powering interface circuits, op amps or data acquisition circuitry off logic supplies is simplified. TYPICAL APPLICATIO Output Voltage Voltage Doubler and Inverter C1 1µF 10 C = 1µF VIN = 5V TA = 25°C + 8 C2 1µF 1 C1– +VOUT 2 C2+ C1+ + 3 4 –VOUT LT1026 C2– –VOUT VIN GND 8 + 7 6 +VOUT 1µF VIN 5 OUTPUT VOLTAGE (V) 6 4 2 0 –2 –4 –6 –8 1µF + –10 1026 • TA01 0 5 15 20 10 LOAD CURRENT (mA) 25 LT1026 • TA02 1026fb 1 LT1026 U W W W ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage ........................................................ 10V V + ............................................................................ 20V V – ..........................................................................– 20V Short-Circuit Duration ......................................... 10 sec Operating Temperature Range LT1026C ................................................. 0°C to 70°C LT1026I .............................................. – 40°C to 85°C LT1026M (OBSOLETE) ............... – 55°C to 125°C Lead Temperature (Soldering, 10 sec)................. 300°C U W U PACKAGE/ORDER INFORMATION TOP VIEW +VOUT C1– 1 8 C1– 1 7 C1+ 8 +VOUT C2+ 2 C2+ 2 6 C2– 3 TOP VIEW TOP VIEW VIN 5 7 C1+ C2– 3 GND 6 VIN –VOUT 4 4 –VOUT 8 +VOUT C2+ 2 7 C1+ C2– 3 6 VIN –VOUT 4 5 GND S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 100°C/W (N8) TJMAX = 150°C, θJA = 150°C/W (S8) TJMAX = 150°C, θJA = 150°C/W TJMAX = 150°C, θJA = 150°C/W 5 GND N8 PACKAGE 8-LEAD PDIP J8 PACKAGE 8-LEAD CERDIP H PACKAGE 8-LEAD TO-5 METAL CAN C1– 1 ORDER PART NUMBER ORDER PART NUMBER ORDER PART NUMBER S8 PART MARKING LT1026CH LT1026MH LT1026CJ8 LT1026MJ8 LT1026CN8 LT1026CS8 LT1026IS8 1026 1026I OBSOLETE PACKAGES Consider the N8 or S8 Packages for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETERS CONDITIONS MIN TYP Output Voltage VIN = 4V (Note 2) IL = 0mA IL = 0mA IL = 10mA IL = – 10mA Positive Negative Positive Negative VIN = 5V IL = 15mA IL = – 15mA VIN = 10V MAX UNITS ● ● ● ● 6.5 –6 5.25 – 4.5 7 – 6.7 5.7 –5 V V V V Positive Negative ● ● 6.25 – 5.5 7 – 6.2 V V IL = 0mA IL = 0mA IL = 10mA IL = – 10mA IL = 15mA IL = – 15mA Positive Negative Positive Negative Positive Negative ● ● ● ● ● ● 18 – 17.7 16 – 15.3 15.25 – 14.5 18.5 – 18 17.6 – 17 17 – 16.5 V V V V V V VIN = 5V IL = 10mA, – 10mA Positive Negative ● ● 6.25 – 5.5 7.2 – 6.5 V V VIN = 10V IL = 10mA, – 10mA Positive Negative ● ● 15 – 14.25 16.8 – 15.75 V V 1026fb 2 LT1026 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETERS CONDITIONS Supply Current VIN = 4V VIN = 10V MIN IL = 0mA IL = 0mA ● ● TYP MAX UNITS 7 15 12.5 30 mA mA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: VIN min = – 4.5 for TA ≤ 40°C U W TYPICAL PERFORMANCE CHARACTERISTICS Load Regulation (Both Outputs Loaded) Load Regulation for Positive Loading C = 1µF VIN = 5V TA = 25°C 8 OUTPUT VOLTAGE (V) 4 2 0 –2 –4 10 8 8 6 6 4 2 –2 –4 –6 –6 –8 –8 –10 0 5 15 20 10 LOAD CURRENT (mA) –10 25 C = 1µF VIN = 5V TA = 25°C 0 IL = 0 0 5 Supply Current SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) –4 30 15 C = 22µF VIN = 5V TA = 25°C NEGATIVE OUTPUT LOADED 25 LT1026 • TPC04 15 20 10 LOAD CURRENT (mA) 25 LT1026 • TPC03 40 C = 22µF VIN = 5V TA = 25°C POSITIVE OUTPUT LOADED 50 30 20 40 30 20 10 0 10 15 20 OUTPUT CURRENT (mA) 5 Supply Current 10 0 0 60 50 45 5 –2 Supply Current C = 22µF VIN = 5V TA = 25°C BOTH OUTPUTS LOADED C = 1µF VIN = 5V TA = 25°C 0 –10 25 60 0 2 LT1026 • TPC02 90 60 4 –8 15 20 10 LOAD CURRENT (mA) LT1026 • TPC01 75 IL = 0 –6 SUPPLY CURRENT (mA) OUTPUT VOLTAGE (V) 6 10 OUTPUT VOLTAGE (V) 10 Load Regulation for Negative Loading 0 0 5 10 15 20 OUTPUT CURRENT (mA) 25 LT1026 • TPC05 0 5 10 15 20 OUTPUT CURRENT (mA) 25 LT1026 • TPC06 1026fb 3 LT1026 U W TYPICAL PERFORMANCE CHARACTERISTICS Ripple Output Voltage vs Temperature 10 60 VIN = 5V IL = 5mV BOTH OUTPUTS 8 6 OUTPUT VOLTAGE (V) RIPPLE (mVP-P) 50 40 30 20 4 2 0 –2 C = 22µF VIN = 5V IL = 1mA –4 –6 10 –8 0 1.0 2.2 47 4.7 10 22 OUTPUT CAPACITOR (µF) 100 1026 • TPC07 –10 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 LT1026 • TPC08 U W U U APPLICATIONS INFORMATION The LT1026 is a nonregulating voltage converter that converts a single input voltage into both a positive and negative output at up to 15mA. A positive input voltage is first doubled and then the doubled voltage is inverted. The voltage output level is dependent on both the input voltage and the output loading. The total output current available depends on the individual loading of the outputs since loading on one output affects the load and the voltage of the other. Only four external components are needed for operation. Two charge pump capacitors and two output storage capacitors. Nominal value for these capacitors is 1µF, but the LT1026 will operate (with reduced performance) down to 0.1µF. Higher value capacitors (22µF) will reduce ripple and slightly lower output impedance. For higher output currents the outputs of several converters may be paralleled with common output capacitors. The substrate diodes are an inherent part of the IC, and must always be reversed biased to isolate the individual transistors. In the LT1026 the substrate is tied to the negative output. If the negative output is not used, such as when only the voltage doubler output is needed, – VOUT must be tied to ground so the substrate diodes are properly biased. The substrate diodes must never become forward biased even during overload conditions. For example, pulling – VOUT positive with respect to ground can forward bias the substrate diodes. Clamping the substrate to ground with an external diode would be needed to ensure proper operation and prevent the substrate from carrying any current. No overload protection is included on the LT1026. Neither output is damaged by momentary shorts, but during sustained shorts the resulting high current flow will overheat the IC. 1026fb 4 LT1026 U TYPICAL APPLICATIONS Positive to Negative Converter 1 C1– 2 C2+ + 1µF 3 4 –VOUT +VOUT C1+ LT1026 C2– VIN –VOUT GND 8 1µF NC + NC Voltage Doubler 7 1 6 C1– VIN 2 5 C2+ C2– + 4 1026 • TA03 C1+ LT1026 3 1µF +VOUT VIN –VOUT GND 8 + 7 6 VOUT 1µF VIN 5 1026 • TA04 Standard Configuration Voltage Doubler and Inverter Voltage Quadrupler C1 1µF C1 1µF 2 + 3 4 –VOUT +VOUT C2+ C1+ LT1026 C2– VIN –VOUT GND 8 + 7 6 1 +VOUT 2 1µF C2 1µF VIN + 3 5 4 C1– +VOUT 8 + 7 C1+ C2+ LT1026 C2– VIN –VOUT GND +VOUT 1µF 6 5 VIN (FLOATING) + 1µF + 1026 • TA05 1026 • TA06 1µF Parallel Converters for Higher Output Current and Lower Output Impedance C1 1µF C1 1µF 2 C2 1µF + 3 4 C1– + + 1 +VOUT C2+ C1+ LT1026 C2– –VOUT VIN GND 8 1 7 2 6 VIN + C2 1µF 3 5 4 C1– +VOUT C2+ C1+ LT1026 C2– –VOUT VIN GND 8 + 7 6 +VOUT 1µF VIN 5 1026 • TA07 –VOUT + C2 1µF C1– + + 1 1µF 1026fb 5 LT1026 U TYPICAL APPLICATIONS 5V Powered RS232 Line Driver C1 1µF + 1 C1– +VOUT 2 C2+ C1+ + 3 4 LT1026 C2– VIN –VOUT GND 8 + 7 6 LT1030 1µF 5VIN 5 LOGIC LINE + 1026 • TA08 U PACKAGE DESCRIPTION H Package 8-Lead TO-5 Metal Can (.230 Inch PCD) (Reference LTC DWG # 05-08-1321) .335 – .370 (8.509 – 9.398) DIA .305 – .335 (7.747 – 8.509) .040 (1.016) MAX .027 – .045 (0.686 – 1.143) 45°TYP .050 (1.270) MAX SEATING PLANE .165 – .185 (4.191 – 4.699) GAUGE PLANE .010 – .045* (0.254 – 1.143) .028 – .034 (0.711 – 0.864) PIN 1 .230 (5.842) TYP REFERENCE PLANE .500 – .750 (12.700 – 19.050) H8 (TO-5) 0.230 PCD 0801 .110 – .160 (2.794 – 4.064) INSULATING STANDOFF .016 – .021** (0.406 – 0.533) *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND THE SEATING PLANE .016 – .024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) OBSOLETE PACKAGE 1026fb 6 LT1026 U PACKAGE DESCRIPTION J8 Package 8-Lead CERDIP (Narrow .300 Inch, Hermetic) (Reference LTC DWG # 05-08-1110) .300 BSC (7.62 BSC) CORNER LEADS OPTION (4 PLCS) .008 – .018 (0.203 – 0.457) .015 – .060 (0.381 – 1.524) .023 – .045 (0.584 – 1.143) HALF LEAD OPTION 0° – 15° .045 – .068 (1.143 – 1.650) FULL LEAD OPTION .405 (10.287) MAX .005 (0.127) MIN .200 (5.080) MAX 8 NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS .014 – .026 (0.360 – 0.660) 5 .025 (0.635) RAD TYP .220 – .310 (5.588 – 7.874) 1 .045 – .065 (1.143 – 1.651) 6 7 2 3 4 J8 0801 .125 3.175 MIN .100 (2.54) BSC OBSOLETE PACKAGE N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 +0.889 8.255 –0.381 .400* (10.160) MAX .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP ) 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 .100 (2.54) BSC N8 1002 (0.457 ± 0.076) NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .004 – .010 (0.101 – 0.254) 8 7 6 .045 ±.005 5 .050 BSC 0°– 8° TYP .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN .053 – .069 (1.346 – 1.752) .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) .050 (1.270) BSC .150 – .157 .245 (3.810 – 3.988) MIN NOTE 3 .228 – .244 (5.791 – 6.197) 1 2 3 4 .030 ±.005 TYP .160 ±.005 SO8 0303 RECOMMENDED SOLDER PAD LAYOUT 1026fb 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. 7 LT1026 U TYPICAL APPLICATION Regulated Converter C1 1µF + 1 2 + C2 1µF 3 4 C1– +VOUT C2+ C1+ LT1026 C2– –VOUT VIN GND 8 + 7 6 +VOUT 9 1µF 8 VIN ≥ 4V INPUT – 3 VIN GND OUT 2 5V 500k 5 5 LT1020 COMP/PNP FB INPUT + 1µF REFOUT + 7 COMP/NPN 4 6 0.001µF + 11 10µF 500k + 10µF 0.001µF 1M 500k 500k –5V REG 10mA 1026 • TA09 2N3904 51k RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1044 Switched Capacitor Voltage Converter Can be Used as Inverter/Doubler/Divider or a Multiplier, VIN = 1.5V to 9V, IQ = 60µA, SO-8 LT1054/LT1054L Switched Capacitors Voltage Converters with Regulator IOUT to 100mA/125mA, VIN = 3.5V to 15V, Inverter, Neg/Pos Doubler LTC1517-5 Micropower, Regulated 5V In SOT-23 Ultralow Power: ICC = 6µA Typical, Small 5-Pin SOT-23 LTC1550/LTC1551 Low Noise, Switched Capacitor Regulator Voltage Inverter < 1mVp-p Typical Output Ripple, 900kHz, IOUT = 10mA LTC1555/LTC1556 SIM Power Supply and Level Translator Step-Up/Step-Down Generates 5V, Input Voltage Range: 2.7V to 10V, > 10kV ESD, Short-Circuit and Overtemp Protection 1026fb 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com LT/TP 0203 REV B 1K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1988