LT1026 Voltage Converter U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ 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 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. 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. Other Linear Technology voltage converters such as the low power LTC ® 1044 CMOS and 100mA bipolar LT1054 are available. APPLICATIONS ■ ■ ■ ■ Line Drivers Op Amp Suppliers Battery Splitters RS232 Power , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATION 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 1 LT1026 U W W W ABSOLUTE MAXIMUM RATINGS 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 .......................................... – 55°C to 125°C Lead Temperature (Soldering, 10 sec)................. 300°C U W U PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW +VOUT C1– 1 8 + 7 C1 C2+ 2 C2– 3 6 5 LT1026CH LT1026MH VIN ORDER PART NUMBER TOP VIEW C1– 1 8 +VOUT C2+ 2 7 C1+ C2– 3 6 VIN –VOUT 4 5 GND J8 PACKAGE 8-LEAD CERAMIC DIP N8 PACKAGE 8-LEAD PLASTIC DIP LT1026CJ8 LT1026CN8 LT1026CS8 LT1026IS8 LT1026MJ8 GND 4 –VOUT H PACKAGE 8-LEAD TO-5 METAL CAN S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/W (H8) TJMAX = 150°C, θJA = 150°C/W (J8) TJMAX = 150°C, θJA = 100°C/W (N8) TJMAX = 150°C, θJA = 150°C/W (S8) S8 PART MARKING 1026 1026I ELECTRICAL CHARACTERISTICS PARAMETERS CONDITIONS MIN TYP Output Voltage VIN = 4V (Note 1) IL = 0mA IL = 0mA IL = 10mA IL = – 10mA Positive Negative Positive Negative ● ● ● ● 6.5 –6 5.25 – 4.5 7 – 6.7 5.7 –5 V V V V VIN = 5V IL = 15mA IL = – 15mA Positive Negative ● ● 6.25 – 5.5 7 – 6.2 V V VIN = 10V 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 VIN = 4V VIN = 10V IL = 0mA IL = 0mA Supply Current The ● denotes specifications which apply over the specified operating temperature range. Loads are applied to individual outputs unless otherwise marked. Note 1: VIN min = – 4.5 for TA ≤ 40°C 2 ● ● 7 15 MAX 12.5 30 UNITS mA mA LT1026 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) OUTPUT VOLTAGE (V) 6 4 2 0 –2 –4 10 10 8 8 6 6 4 2 –2 –4 –6 –8 –8 0 5 15 20 10 LOAD CURRENT (mA) C = 1µF VIN = 5V TA = 25°C 0 –6 –10 –10 25 Supply Current IL = 0 5 0 15 25 0 C = 22µF VIN = 5V TA = 25°C NEGATIVE OUTPUT LOADED 5 15 20 10 LOAD CURRENT (mA) 40 30 20 25 25 LT1026 • TPC03 C = 22µF VIN = 5V TA = 25°C POSITIVE OUTPUT LOADED 50 40 30 20 10 0 0 10 15 20 OUTPUT CURRENT (mA) 0 Supply Current 10 0 5 25 10 15 20 OUTPUT CURRENT (mA) LT1026 • TPC04 0 5 10 15 20 OUTPUT CURRENT (mA) LT1026 • TPC05 Ripple 25 LT1026 • TPC06 Output Voltage vs Temperature 10 60 VIN = 5V IL = 5mV BOTH OUTPUTS 8 6 OUTPUT VOLTAGE (V) 50 RIPPLE (mVP-P) –4 –10 15 20 10 LOAD CURRENT (mA) SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 30 5 –2 60 50 45 C = 1µF VIN = 5V TA = 25°C 0 Supply Current C = 22µF VIN = 5V TA = 25°C BOTH OUTPUTS LOADED 0 2 –8 60 60 4 LT1026 • TPC02 90 75 IL = 0 –6 LT1026 • TPC01 SUPPLY CURRENT (mA) OUTPUT VOLTAGE (V) 10 Load Regulation for Negative Loading 40 30 20 4 2 0 –2 C = 22µF VIN = 5V IL = 1mA –4 –6 10 –8 0 1.0 2.2 4.7 10 22 47 OUTPUT CAPACITOR (µF) 100 1026 • TPC07 –10 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 LT1026 • TPC08 3 LT1026 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. 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. 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. 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. U TYPICAL APPLICATIONS Positive to Negative Converter 1 –VOUT 2 1µF + 1µF 3 + 4 C1– +VOUT C2+ C1+ LT1026 C2– VIN –VOUT GND 8 NC 7 6 VIN 5 1026 • TA03 Voltage Doubler 1µF + 1 2 3 4 C1– +VOUT LT1026 –VOUT + 7 C1+ C2+ C2– 8 VIN GND 6 1µF VIN 5 1026 • TA04 4 VOUT LT1026 U TYPICAL APPLICATIONS Standard Configuration Voltage Doubler and Inverter C1 1µF + 1 C1– +VOUT 2 C2+ C1+ + C2 1µF 3 4 –VOUT 8 LT1026 C2– –VOUT 1µF 6 VIN +VOUT + 7 VIN 5 GND 1µF + 1026 • TA05 Voltage Quadrupler C1 1µF + 1 2 + C2 1µF 3 4 C1– +VOUT C2+ C1+ LT1026 C2– VIN –VOUT GND 8 + 7 +VOUT 1µF 6 VIN (FLOATING) 5 + 1026 • TA06 1µF Parallel Converters for Higher Output Current and Lower Output Impedance C1 1µF C1 1µF C2 1µF + 3 4 8 1 7 C1+ 2 +VOUT C2+ LT1026 C2– –VOUT VIN GND 6 VIN C2 1µF 5 + 3 4 C1– +VOUT LT1026 –VOUT + 7 C1+ C2+ C2– 8 VIN GND 6 +VOUT 1µF VIN 5 1026 • TA07 –VOUT + 2 C1– + + 1 1µF 5 LT1026 U TYPICAL APPLICATIONS 5V Powered RS232 Line Driver C1 1µF + 1 C1– +VOUT 2 C2+ C1+ + LT1026 3 C2– 4 VIN –VOUT GND 8 + 7 6 1µF LT1030 5VIN 5 LOGIC LINE + 1026 • TA08 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. H Package 8-Lead TO-5 Metal Can (0.230 PCD) (LTC DWG # 05-08-1321) 0.335 – 0.370 (8.509 – 9.398) DIA 0.305 – 0.335 (7.747 – 8.509) 0.040 (1.016) MAX 0.050 (1.270) MAX SEATING PLANE 0.165 – 0.185 (4.191 – 4.699) GAUGE PLANE 0.010 – 0.045* (0.254 – 1.143) REFERENCE PLANE 0.500 – 0.750 (12.700 – 19.050) 0.016 – 0.021** (0.406 – 0.533) 0.027 – 0.045 (0.686 – 1.143) 45°TYP 0.028 – 0.034 (0.711 – 0.864) PIN 1 0.230 (5.842) TYP 0.110 – 0.160 (2.794 – 4.064) INSULATING STANDOFF *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND 0.045" BELOW THE REFERENCE PLANE 0.016 – 0.024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) H8 (TO-5) 0.230 PCD 1197 6 LT1026 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. J8 Package 8-Lead CERDIP (Narrow 0.300, Hermetic) (LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) 0.405 (10.287) MAX 0.005 (0.127) MIN 0.023 – 0.045 (0.584 – 1.143) HALF LEAD OPTION 8 6 7 5 0.025 (0.635) RAD TYP 0.045 – 0.068 (1.143 – 1.727) FULL LEAD OPTION 0.220 – 0.310 (5.588 – 7.874) 1 2 3 4 0.300 BSC (0.762 BSC) 0.200 (5.080) MAX 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0° – 15° NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS 0.045 – 0.068 (1.143 – 1.727) 0.125 3.175 0.100 ± 0.010 MIN (2.540 ± 0.254) 0.014 – 0.026 (0.360 – 0.660) J8 1197 N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 ) 0.045 – 0.065 (1.143 – 1.651) 0.130 ± 0.005 (3.302 ± 0.127) 0.065 (1.651) TYP 0.100 ± 0.010 (2.540 ± 0.254) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1197 *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) 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 8 + 7 C1+ C2+ LT1026 C2– VIN –VOUT GND 6 +VOUT 9 1µF 8 VIN ≥ 4V INPUT – 3 VIN GND 2 OUT 5V 0.001µF 500k 5 5 LT1020 COMP/PNP FB INPUT + 1µF REFOUT + 7 10µF 500k COMP/NPN 4 + 11 6 + 10µF 0.001µF 1M 500k 500k –5V REG 10mA 1026 • TA09 2N3904 51k U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 8 7 6 5 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE SO8 0996 1 2 3 4 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS 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 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com 1026fa LT/TP 0498 REV A 2K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1988