1
LT1026
Voltage Converter
D
U
ESCRIPTIO
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.
The LT1026 offers a convenient way of generating addi-
tional 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
■
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
FEATURES
APPLICATIONS
U
■
Line Drivers
■
Op Amp Suppliers
■
Battery Splitters
■
RS232 Power
TYPICAL APPLICATION
U
Voltage Doubler and Inverter
C1–
C2+
C2–
–VOUT
8
7
6
5
1
2
3
4
+VOUT
C1+
VIN
GND
LT1026
+
C1
1µF
VIN
++
+VOUT
1µF
C2
1µF
–VOUT
+
1µF
1026 • TA01
Output Voltage
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
10
20
LT1026 • TA02
–6
2
6
–2
0
4
8
–4
–8
–10 510 15 25
C = 1µF
V
IN
= 5V
T
A
= 25°C
2
LT1026
ABSOLUTE MAXIMUM RATINGS
WWWU
Supply Voltage ........................................................10V
V
+
............................................................................20V
V
–
..........................................................................–20V
Short-Circuit Duration .........................................10 sec
1
2
3
4
8
7
6
5
TOP VIEW
J8 PACKAGE
8-LEAD CERAMIC DIP N8 PACKAGE
8-LEAD PLASTIC DIP
S8 PACKAGE
8-LEAD PLASTIC SO
C1–
C2+
C2–
–VOUT
+VOUT
C1+
VIN
GND
ORDER PART
NUMBER
LT1026CJ8
LT1026CN8
LT1026CS8
LT1026IS8
LT1026MJ8
S8 PART MARKING
1026
1026I
T
JMAX
= 150°C, θ
JA
= 150°C/W (J8)
T
JMAX
= 150°C, θ
JA
= 100°C/W (N8)
T
JMAX
= 150°C, θ
JA
= 150°C/W (S8)
ORDER PART
NUMBER
LT1026CH
LT1026MH
T
JMAX
= 150°C, θ
JA
= 150°C/W (H8)
ELECTRICAL CHARACTERISTICS
PARAMETERS CONDITIONS MIN TYP MAX UNITS
Output Voltage V
IN
= 4V I
L
= 0mA Positive ●6.5 7 V
(Note 1) I
L
= 0mA Negative ●–6 –6.7 V
I
L
= 10mA Positive ●5.25 5.7 V
I
L
= –10mA Negative ●–4.5 –5 V
V
IN
= 5V I
L
= 15mA Positive ●6.25 7 V
I
L
= –15mA Negative ●–5.5 –6.2 V
V
IN
= 10V I
L
= 0mA Positive ●18 18.5 V
I
L
= 0mA Negative ●–17.7 –18 V
I
L
= 10mA Positive ●16 17.6 V
I
L
= –10mA Negative ●–15.3 –17 V
I
L
= 15mA Positive ●15.25 17 V
I
L
= –15mA Negative ●–14.5 –16.5 V
V
IN
= 5V I
L
= 10mA, –10mA Positive ●6.25 7.2 V
Negative ●–5.5 –6.5 V
V
IN
= 10V I
L
= 10mA, –10mA Positive ●15 16.8 V
Negative ●–14.25 –15.75 V
Supply Current V
IN
= 4V I
L
= 0mA ●7 12.5 mA
V
IN
= 10V I
L
= 0mA ●15 30 mA
The ● denotes specifications which apply over the specified operating
temperature range. Loads are applied to individual outputs unless otherwise
marked.
Note 1: V
IN
min = –4.5 for T
A
≤ 40°C
TOP VIEW
C1
+
+V
OUT
C1
–
C2
+
V
IN
GND
C2
–
–V
OUT
87
6
5
3
2
1
4
H PACKAGE
8-LEAD TO-5 METAL CAN
PACKAGE/ORDER INFORMATION
UUW
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
3
LT1026
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Load Regulation (Both Outputs
Loaded)
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
10
20
LT1026 • TPC01
–6
2
6
–2
0
4
8
–4
–8
–10 510 15 25
C = 1µF
V
IN
= 5V
T
A
= 25°C
Load Regulation for Negative
Loading
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
10
20
LT1026 • TPC03
–6
2
6
–2
0
4
8
–4
–8
–10 510 15 25
C = 1µF
V
IN
= 5V
T
A
= 25°C
I
L
= 0
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
10
20
LT1026 • TPC02
–6
2
6
–2
0
4
8
–4
–8
–10 510 15 25
C = 1µF
V
IN
= 5V
T
A
= 25°C
I
L
= 0
Load Regulation for Positive
Loading
Supply Current Supply CurrentSupply Current
OUTPUT CURRENT (mA)
0
0
SUPPLY CURRENT (mA)
15
30
45
60
75
90
5101520
LT1026 • TPC04
25
C = 22µF
V
IN
= 5V
T
A
= 25°C
BOTH OUTPUTS
LOADED
OUTPUT CURRENT (mA)
0
0
SUPPLY CURRENT (mA)
10
20
30
40
50
60
5101520
LT1026 • TPC05
25
C = 22µF
V
IN
= 5V
T
A
= 25°C
NEGATIVE
OUTPUT
LOADED
OUTPUT CURRENT (mA)
0
0
SUPPLY CURRENT (mA)
10
20
30
40
50
60
5101520
LT1026 • TPC06
25
C = 22µF
V
IN
= 5V
T
A
= 25°C
POSITIVE
OUTPUT
LOADED
Ripple Output Voltage vs Temperature
OUTPUT CAPACITOR (µF)
1.0
0
RIPPLE (mVP-P)
10
20
30
40
60
2.2 4.7 10 22
1026 • TPC07
47 100
50
VIN = 5V
IL = 5mV
BOTH OUTPUTS
TEMPERATURE (°C)
–50
–10
OUTPUT VOLTAGE (V)
–8
–4
–2
0
10
4
050 75
LT1026 • TPC08
–6
6
8
2
–25 25 100 125
C = 22µF
V
IN
= 5V
I
L
= 1mA
4
LT1026
APPLICATIONS INFORMATION
UWUU
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 paral-
leled 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, –V
OUT
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 ex-
ample, pulling –V
OUT
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 over-
heat the IC.
TYPICAL APPLICATIONS
U
Positive to Negative Converter
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026 V
IN
+
+
–V
OUT
1µF
1026 • TA03
NC
1µF
Voltage Doubler
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026
+
1µF
V
IN
+
V
OUT
1µF
1026 • TA04
5
LT1026
TYPICAL APPLICATIONS
U
Standard Configuration Voltage Doubler and Inverter
Voltage Quadrupler
C1–
C2+
C2–
–VOUT
8
7
6
5
1
2
3
4
+VOUT
C1+
VIN
GND
LT1026
+
C1
1µF
VIN
++
+VOUT
1µF
–VOUT
+
1µF
1026 • TA05
C2
1µF
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026
+
C1
1µF
+
1µF
V
IN
(FLOATING)
++
+V
OUT
1µF
C2
1µF
1026 • TA06
Parallel Converters for Higher Output Current and Lower Output Impedance
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026
+
C1
1µF
V
IN
+
C2
1µF
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026
+
C1
1µF
V
IN
+
C2
1µF
1026 • TA07
+
+V
OUT
1µF
+
1µF
–V
OUT
6
LT1026
5V Powered RS232 Line Driver
C1–
C2+
C2–
–VOUT
8
7
6
5
1
2
3
4
+VOUT
C1+
VIN
GND
LT1026
+
C1
1µF
5VIN
++
1µF
+
1026 • TA08
LT1030
LINELOGIC
TYPICAL APPLICATIONS
U
PACKAGE DESCRIPTION
U
Dimensions in inches (millimeters) unless otherwise noted.
0.050
(1.270)
MAX
0.016 – 0.021**
(0.406 – 0.533)
0.010 – 0.045*
(0.254 – 1.143)
SEATING
PLANE
0.040
(1.016)
MAX 0.165 – 0.185
(4.191 – 4.699)
GAUGE
PLANE
REFERENCE
PLANE
0.500 – 0.750
(12.700 – 19.050)
0.305 – 0.335
(7.747 – 8.509)
0.335 – 0.370
(8.509 – 9.398)
DIA
0.230
(5.842)
TYP
0.027 – 0.045
(0.686 – 1.143)
0.028 – 0.034
(0.711 – 0.864)
0.110 – 0.160
(2.794 – 4.064)
INSULATING
STANDOFF
45°TYP
H8 (TO-5) 0.230 PCD 1197
LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND 0.045" BELOW THE REFERENCE PLANE
FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS 0.016 – 0.024
(0.406 – 0.610)
*
**
PIN 1
H Package
8-Lead TO-5 Metal Can (0.230 PCD)
(LTC DWG # 05-08-1321)
7
LT1026
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 represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
U
Dimensions in inches (millimeters) unless otherwise noted.
J8 Package
8-Lead CERDIP (Narrow 0.300, Hermetic)
(LTC DWG # 05-08-1110)
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
J8 1197
0.014 – 0.026
(0.360 – 0.660)
0.200
(5.080)
MAX
0.015 – 0.060
(0.381 – 1.524)
0.125
3.175
MIN
0.100 ± 0.010
(2.540 ± 0.254)
0.300 BSC
(0.762 BSC)
0.008 – 0.018
(0.203 – 0.457) 0° – 15°
0.005
(0.127)
MIN
0.405
(10.287)
MAX
0.220 – 0.310
(5.588 – 7.874)
1234
8765
0.025
(0.635)
RAD TYP
0.045 – 0.068
(1.143 – 1.727)
FULL LEAD
OPTION
0.023 – 0.045
(0.584 – 1.143)
HALF LEAD
OPTION
CORNER LEADS OPTION
(4 PLCS)
0.045 – 0.068
(1.143 – 1.727)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
N8 1197
0.100 ± 0.010
(2.540 ± 0.254)
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651) 0.130 ± 0.005
(3.302 ± 0.127)
0.020
(0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.125
(3.175)
MIN
12 34
8765
0.255 ± 0.015*
(6.477 ± 0.381)
0.400*
(10.160)
MAX
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
8
LT1026
1234
0.150 – 0.157**
(3.810 – 3.988)
8765
0.189 – 0.197*
(4.801 – 5.004)
0.228 – 0.244
(5.791 – 6.197)
0.016 – 0.050
0.406 – 1.270
0.010 – 0.020
(0.254 – 0.508)× 45°
0°– 8° TYP
0.008 – 0.010
(0.203 – 0.254)
SO8 0996
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
TYP
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
*
**
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear-tech.com
LINEAR TECHNOLOGY CORPORATION 1988
1026fa LT/TP 0498 REV A 2K • PRINTED IN USA
Regulated Converter
C1
–
C2
+
C2
–
–V
OUT
8
7
6
5
1
2
3
4
+V
OUT
C1
+
V
IN
GND
LT1026
+
C1
1µF
V
IN
≥ 4V
++
+V
OUT
1µF
C2
1µF
+
1µF
1026 • TA09
GND
INPUT–
INPUT+
COMP/PNP
OUT
FB
REFOUT COMP/NPN
LT1020
V
IN
2
11
647
93
500k
500k
0.001µF
+
10µF
5V
+
10µF
500k1M 500k
0.001µF
–5V REG 10mA
51k
5
8
2N3904
TYPICAL APPLICATION
U
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
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CC
= 6µA Typical, Small 5-Pin SOT-23
LTC1550/LTC1551 Low Noise, Switched Capacitor Regulator Voltage Inverter < 1mVp-p Typical Output Ripple, 900kHz, I
OUT
= 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
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
PACKAGE DESCRIPTION
U
Dimensions in inches (millimeters) unless otherwise noted.
