LTC1044A
1
1044afa
For more information www.linear.com/LTC1044A
Typical applicaTion
FeaTures DescripTion
12V CMOS
Voltage Converter
Generating –10V from 10V Output Voltage vs Load Current, V+ = 10V
applicaTions
n 1.5V to 12V Operating Supply Voltage Range
n 13V Absolute Maximum Rating
n 200µA Maximum No Load Supply Current at 5V
n Boost Pin (Pin 1) for Higher Switching Frequency
n 97% Minimum Open Circuit Voltage Conversion
Efficiency
n 95% Minimum Power Conversion Efficiency
n IS = 1.5µA with 5V Supply When OSC Pin = 0V or V+
n High Voltage Upgrade to ICL7660/LTC1044
n Conversion of 10V to ±10V Supplies
n Conversion of 5V to ±5V Supplies
n Precise Voltage Division: VOUT = VIN/2 ±20ppm
n Voltage Multiplication: VOUT = ±nVIN
n Supply Splitter: VOUT = ±VS/2
n Automotive Applications
n Battery Systems with 9V Wall Adapters/Chargers
L, LT , LT C , LT M , Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
The LT C
®
1044A is a monolithic CMOS switched-capacitor
voltage converter. It plugs in for ICL7660/LTC1044 in
applications where higher input voltage (up to 12V) is
needed. The LTC1044A provides several conversion func-
tions without using inductors. The input voltage can be
inverted (VOUT = –VIN), doubled (VOUT = 2VIN), divided
(VOUT = VIN/2) or multiplied (VOUT = ±nVIN).
To optimize performance in specific applications, a boost
function is available to raise the internal oscillator frequency
by a factor of seven. Smaller external capacitors can be
used in higher frequency operation to save board space.
The internal oscillator can also be disabled to save power.
The supply current drops to 1.5µA at 5V input when the
OSC pin is tied to GND or V+.
1
2
3
4
8
7
6
5
LTC1044A
V+
OSC
LV
VOUT
BOOST
CAP+
GND
CAP–
+10µF
+
10µF
10V INPUT
–10V OUTPUT
1044a TA01a
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
–4
–2
0
40
1044a TA01b
–6
–8
–5
–3
–1
–7
–9
–10 10 20 30 50 60 70 80 90 100
TA = 25°C
C1 = C2 = 10µF
SLOPE = 45Ω
LTC1044A
2
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pin conFiguraTion
absoluTe MaxiMuM raTings
Supply Voltage ..........................................................13V
Input Voltage on Pins 1, 6 and 7
(Note 2) ..................................–0.3V < VIN < V+ + 0.3V
Current into Pin 6 .................................................... 20µA
Output Short-Circuit Duration
V+ ≤ 6.5V ......................................................Continuous
(Note 1)
1
2
3
4
8
7
6
5
TOP VIEW
BOOST
CAP+
GND
CAP–
V+
OSC
LV
VOUT
N8 PACKAGE
8-LEAD PLASTIC DIP
TJMAX = 110°C, θJA = 100°C/W
1
2
3
4
8
7
6
5
TOP VIEW
V+
OSC
LV
VOUT
BOOST
CAP+
GND
CAP–
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 110°C, θJA = 130°C/W
Consult factory for military grade parts
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC1044ACN8#PBF LTC1044ACN8#TRPBF LTC1044 ACN8 8-Lead Plastic DIP 0°C to 70°C
LTC1044AIN8#PBF LTC1044AIN8#TRPBF LTC1044 AIN8 8-Lead Plastic DIP –40°C to 85°C
LTC1044ACS8#PBF LTC1044ACS8#TRPBF 1044A 8-Lead Plastic SO 0°C to 70°C
LTC1044AIS8#PBF LTC1044AIS8#TRPBF 1044AI 8-Lead Plastic SO –40°C to 85°C
Consult LT C Marketing for parts specified with wider operating temperature ranges.
Consult LT C Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
Operating Temperature Range
LTC1044AC .............................................. 0°C to 70°C
LTC1044AI ........................................... –40°C to 85°C
Storage Temperature Range ................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
LTC1044A
3
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elecTrical characTerisTics
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Connecting any input terminal to voltages greater than V+ or less
than ground may cause destructive latchup. It is recommended that no
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, COSC = 0pF, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS
LTC1044AC LTC1044AI
UNITSMIN TYP MAX MIN TYP MAX
ISSupply Current RL = ∞, Pins 1 and 7, No Connection
RL = ∞, Pins 1 and 7, No Connection,
V+ = 3V
60
15
200 60
15
200 μA
μA
Minimum Supply Voltage RL = 10k l1.5 1.5 V
Maximum Supply Voltage RL = 10k l12 12 V
ROUT Output Resistance IL = 20mA, fOSC = 5kHz
V+ = 2V, IL = 3mA, fOSC = 1kHz
l
l
100
120
310
100
130
325
Ω
Ω
Ω
fOSC Oscillator Frequency V+ = 5V, (Note 3)
V+ = 2V
l
l
5
1
5
1
kHz
kHz
PEFF Power Efficiency RL = 5k, fOSC = 5kHz 95 98 95 98 %
Voltage Conversion Efficiency RL = ∞ 97 99.9 97 99.9 %
Oscillator Sink or Source
Current
VOSC = 0V or V+
Pin 1 (BOOST) = 0V
Pin 1 (BOOST) = V+
l
l
3
20
3
20
µA
µA
inputs from sources operating from external supplies be applied prior to
power-up of the LTC1044A.
Note 3: fOSC is tested with COSC = 100pF to minimize the effects of test
fixture capacitance loading. The 0pF frequency is correlated to this 100pF
test point, and is intended to simulate the capacitance at pin 7 when the
device is plugged into a test socket and no external capacitor is used.
LTC1044A
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Typical perForMance characTerisTics
Output Resistance vs Oscillator
Frequency, V+ = 5V
Output Resistance vs Oscillator
Frequency, V+ = 10V
Power Conversion Efficiency vs
Load Current, V+ = 2V
Power Conversion Efficiency vs
Load Current, V+ = 5V
Power Conversion Efficiency vs
Load Current, V+ = 10V
Operating Voltage Range vs
Temperature
Power Efficiency vs Oscillator
Frequency, V+ = 5V
Power Efficiency vs Oscillator
Frequency, V+ = 10V
AMBIENT TEMPERATURE (°C)
–55
8
10
14
25 75
1044a G01
6
4
–25 0 50 100 125
2
0
12
SUPPLY VOLTAGE (V)
OSCILLATOR FREQUENCY (Hz)
100
88
POWER EFFICIENCY (%)
90
92
94
96
1k 10k 100k
1044a G02
86
84
82
80
98
100
100µF
100µF
10µF
10µF
1µF
1µF
IL = 1mA
IL = 15mA
TA = 25°C
C1 = C2
OSCILLATOR FREQUENCY (Hz)
100
200
OUTPUT RESISTANCE (Ω)
300
400
1k 10k 100k
1044a G04
100
0
500
TA = 25°C
IL = 10mA
C1 = C2 = 10µF
C1 = C2 = 1µF
C1 = C2 = 100µF
OSCILLATOR FREQUENCY (Hz)
100
200
OUTPUT RESISTANCE (Ω)
300
400
1k 10k 100k
1044a G05
100
0
500
TA = 25°C
IL = 10mA
C1 = C2 = 1µF
C1 = C2
= 100µF
C1 = C2
= 10µF
LOAD CURRENT (mA)
0
0
POWER CONVERSION EFFICIENCY (%)
SUPPLY CURRENT (mA)
10
30
40
50
100
70
245
1044a G06
20
80
90 PEFF
IS
60
0
1
3
4
5
10
7
2
8
9
6
1367
TA = 25°C
C1 = C2 = 10µF
fOSC = 1kHz
LOAD CURRENT (mA)
0
0
POWER CONVERSION EFFICIENCY (%)
SUPPLY CURRENT (mA)
10
30
40
50
100
70
20 40 50
1044a G07
20
80
90 PEFF
IS
60
0
10
30
40
50
100
70
20
80
90
60
10 30 60 70
TA = 25°C
C1 = C2 = 10µF
fOSC = 5kHz
LOAD CURRENT (mA)
0
0
POWER CONVERSION EFFICIENCY (%)
SUPPLY CURRENT (mA)
10
30
40
50
100
70
40 80 100
1044a G08
20
80
90 PEFF
IS
60
0
30
90
120
150
300
210
60
240
270
180
20 60 120 140
TA = 25°C
C1 = C2 = 10µF
fOSC = 20kHz
OSCILLATOR FREQUENCY (Hz)
100
POWER EFFICIENCY (%)
1k 10k 100k
1044a G03
TA = 25°C
C1 = C2
100µF IL = 1mA
10µF 10µF
1µF 1µF
88
90
92
94
96
86
84
82
80
98
100
100µF
IL = 15mA
LTC1044A
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Typical perForMance characTerisTics
Output Voltage vs Load Current,
V+ = 10V
Output Resistance vs
Temperature
Oscillator Frequency as a
Function of COSC, V+ = 5V
Oscillator Frequency as a
Function of COSC, V+ = 10V
Oscillator Frequency vs Supply
Voltage
Oscillator Frequency vs
Temperature
Output Resistance vs Supply
Voltage
Output Voltage vs Load Current,
V+ = 2V
Output Voltage vs Load Current,
V+ = 5V
SUPPLY VOLTAGE (V)
1
OUTPUT RESISTANCE (Ω)
3
1000
1044a G09
10
100
2 10 11 12
9
876
5
4
0
TA = 25°C
IL = 3mA
COSC = 100pF
COSC = 0pF
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
0.5
1.5
2.5
8
1044a G10
–0.5
–1.5
0
1.0
2.0
–1.0
–2.0
–2.5 24610
7
1359
TA = 25°C
fOSC = 1kHz
SLOPE = 250Ω
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
1
3
5
80
1044a G11
–1
–3
0
2
4
–2
–4
–5 20 40 60 100
70
10 30 50 90
TA = 25°C
fOSC = 5kHz
SLOPE = 80Ω
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE (V)
2
6
10
40
1044a G12
–2
–6
0
4
8
–4
–8
–10 10 20 30 50 60 70 80 90 100
TA = 25°C
fOSC = 20kHz
SLOPE = 45Ω
AMBIENT TEMPERATURE (°C)
–55
0
OUTPUT RESISTANCE (Ω)
40
120
160
200
400
280
050 75
1044a G13
80
320
360
240
–25 25 100 125
V+ = 2V, fOSC = 1kHz
C1 = C2 = 10µF
V+ = 5V, fOSC = 5kHz
V+ = 10V, fOSC = 20kHz
EXTERNAL CAPACITOR (PIN 7 TO GND)(pF)
1 10
10
OSCILLATOR FREQUENCY (Hz)
1k
100k
100 1000 10000
1044a G14
100
10k
TA = 25°C
PIN 1 = V+
PIN 1 = OPEN
EXTERNAL CAPACITOR (PIN 7 TO GND)(pF)
1 10
10
OSCILLATOR FREQUENCY (Hz)
1k
100k
100 1000 10000
1044a G15
100
10k
V+ = 10V
TA = 25°C
PIN 1 = V+
PIN 1 = OPEN
SUPPLY VOLTAGE (V)
0123
OSCILLATOR FREQUENCY (Hz)
1k
10k
100k
4 5 6 7 8 9 10 11 12
1044a G16
0.1k
TA = 25°C
COSC = 0pF
AMBIENT TEMPERATURE (°C)
–55
20
25
35
25 75
1044a G17
15
10
–25 0 50 100 125
5
0
30
OSCILLATOR FREQUENCY (kHz)
V+ = 10V
V+ = 5V
COSC = 0pF
LTC1044A
6
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TesT circuiT
applicaTions inForMaTion
Theory of Operation
To understand the theory of operation of the LTC1044A,
a review of a basic switched-capacitor building block is
helpful.
In Figure 1, when the switch is in the left position, capaci-
tor C1 will charge to voltage V1. The total charge on C1
will be q1 = C1V1. The switch then moves to the right,
discharging C1 to voltage V2. After this discharge time,
the charge on C1 is q2 = C1V2. Note that charge has been
transferred from the source, V1, to the output, V2. The
amount of charge transferred is:
∆q = q1 – q2 = C1(V1 – V2)
If the switch is cycled f times per second, the charge
transfer per unit time (i.e., current) is:
I = f • ∆q = f • C1(V1 – V2)
A new variable, REQUIV, has been defined such that REQUIV
= 1/(f • C1). Thus, the equivalent circuit for the switched-
capacitor network is as shown in Figure 2.
Rewriting in terms of voltage and impedance equivalence,
I
=
V1– V2
1
(f •C1)
=
V1– V2
REQUIV
Figure 1. Switched-Capacitor Building Block
V1
1044a F01
V2
C1
f
C2
RL
Examination of Figure 3 shows that the LTC1044A has the
same switching action as the basic switched-capacitor
building block. With the addition of finite switch-on
resistance and output voltage ripple, the simple theory
although not exact, provides an intuitive feel for how the
device works.
For example, if you examine power conversion efficiency
as a function of frequency (see typical curve), this simple
theory will explain how the LTC1044A behaves. The loss,
and hence the efficiency, is set by the output impedance.
As frequency is decreased, the output impedance will
eventually be dominated by the 1/(f • C1) term, and power
efficiency will drop. The typical curves for Power Efficiency
vs Frequency show this effect for various capacitor values.
Note also that power efficiency decreases as frequency
goes up. This is caused by internal switching losses which
occur due to some finite charge being lost on each switching
cycle. This charge loss per unit cycle, when multiplied by
the switching frequency, becomes a current loss. At high
frequency this loss becomes significant and the power
efficiency starts to decrease.
Figure 2. Switched-Capacitor Equivalent Circuit
V1
1044a F02
V2
C2 RL
REQUIV
REQUIV =1
f × C1
1
2
3
4
8
7
6
5
LTC1044A
V+ (5V)
+C1
10µF
+
C2
10µF
COSC
VOUT
RL
IS
IL
EXTERNAL
OSCILLATOR
1044a TC
LTC1044A
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LV (Pin 6)
The internal logic of the LTC1044A runs between V+ and
LV (pin 6). For V+ greater than or equal to 3V, an internal
switch shorts LV to GND (pin 3). For V+ less than 3V, the
LV pin should be tied to GND. For V+ greater than or equal
to 3V, the LV pin can be tied to GND or left floating.
OSC (Pin 7) and Boost (Pin 1)
The switching frequency can be raised, lowered, or driven
from an external source. Figure 4 shows a functional
diagram of the oscillator circuit.
Loading pin 7 with more capacitance will lower the
frequency. Using the boost (pin 1) in conjunction with
external capacitance on pin 7 allows user selection of the
frequency over a wide range.
Driving the LTC1044A from an external frequency source
can be easily achieved by driving pin 7 and leaving the boost
pin open as shown in Figure 5. The output current from
pin 7 is small (typically 0.5µA) so a logic gate is capable
of driving this current. The choice of using a CMOS logic
gate is best because it can operate over a wide supply
voltage range (3V to 15V) and has enough voltage swing
to drive the internal Schmitt trigger shown in Figure 4. For
5V applications, a TTL logic gate can be used by simply
adding an external pull-up resistor (see Figure 5).
applicaTions inForMaTion
Figure 3. LTC1044A Switched-Capacitor Voltage Converter Block Diagram
Figure 5. External Clocking
Figure 4. Oscillator
7X
(1)
LV
(6)
V+
(8)
OSC ÷ 2
OSC
(7)
C+
(2)
BOOST
C–
(4)
VOUT
(5)
GND
(3)
+
C1
C2
1044a F03
φ
φ
SW1 SW2
CLOSED WHEN
V+ > 3V
+
BOOST
(1)
LV
(6)
OSC
(7)
V+
6I I
6I
~14pF
1044a F04
SCHMITT
TRIGGER
I
1
2
3
4
8
7
6
5
LTC1044A
V+
–(V+)
+
C1
NC
OSC INPUT
C2
100k
REQUIRED FOR
TTL LOGIC
1044a F05
+
By connecting the boost pin (pin 1) to V+, the charge and
discharge current is increased and hence, the frequency
is increased by approximately seven times. Increasing the
frequency will decrease output impedance and ripple for
higher load currents.
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applicaTions inForMaTion
Capacitor Selection
External capacitors C1 and C2 are not critical. Matching is
not required, nor do they have to be high quality or tight
tolerance. Aluminum or tantalum electrolytics are excellent
choices with cost and size being the only consideration.
Negative Voltage Converter
Figure 6 shows a typical connection which will provide
a negative supply from an available positive supply. This
circuit operates over full temperature and power supply
ranges without the need of any external diodes. The LV
pin (pin 6) is shown grounded, but for V+ ≥ 3V it may be
floated, since LV is internally switched to ground (pin 3)
for V+ ≥ 3V.
The output voltage (pin 5) characteristics of the circuit
are those of a nearly ideal voltage source in series with
an 80Ω resistor. The 80Ω output impedance is composed
of two terms:
1. The equivalent switched-capacitor resistance (see
Theory of Operation).
2. A term related to the on-resistance of the MOS
switches.
At an oscillator frequency of 10kHz and C1 = 10µF, the
first term is:
REQUIV =
1
(fOSC / 2)•C1
=1
5•10
3
•10 •10
– 6 = 20Ω
Notice that the above equation for REQUIV is not a capaci-
tive reactance equation (XC = 1/C) and does not contain
a 2π term.
Figure 6. Negative Voltage Converter
The exact expression for output resistance is extremely
complex, but the dominant effect of the capacitor is
clearly shown on the typical curves of Output Resistance
and Power Efficiency vs Frequency. For C1 = C2 = 10µF,
the output impedance goes from 60Ω at fOSC = 10kHz to
200Ω at fOSC = 1kHz. As the 1/(f • C) term becomes large
compared to the switch-on resistance term, the output
resistance is determined by 1/(f • C) only.
Voltage Doubling
Figure 7 shows a two-diode capacitive voltage doubler.
With a 5V input, the output is 9.93V with no load and 9.13V
with a 10mA load. With a 10V input, the output is 19.93V
with no load and 19.28V with a 10mA load.
1
2
3
4
8
7
6
5
LTC1044A
VOUT = –V+
REQUIRED FOR V+ < 3V
V+ (1.5V TO 12V)
TMIN ≤ TA ≤ TMAX
+
+
10µF
10µF
1044a F06
Ultra-Precision Voltage Divider
An ultra-precision voltage divider is shown in Figure 8. To
achieve the 0.002% accuracy indicated, the load current
should be kept below 100nA. However, with a slight loss
in accuracy the load current can be increased.
Figure 7. Voltage Doubler
1
2
3
4
8
7
6
5
LTC1044A
VIN
(1.5V TO 12V)
VOUT = 2(VIN – 1)
Vd
1N5817
Vd
1N5817
REQUIRED
FOR V+ < 3V
1044a F07
+
+
+
+
10µF 10µF
Figure 8. Ultra-Precision Voltage Divider
1
2
3
4
8
7
6
5
LTC1044A
V+ (3V TO 24V)
+C1
10µF
V+/2 ±0.002% +C2
10µF
REQUIRED FOR
V+ < 6V
1044a F08
TMIN ≤ TA ≤ TMAX
IL ≤ 100nA
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applicaTions inForMaTion
Battery Splitter
A common need in many systems is to obtain (+) and
(–) supplies from a single battery or single power supply
system. Where current requirements are small, the circuit
shown in Figure 9 is a simple solution. It provides sym-
metrical ± output voltages, both equal to one half input
voltage. The output voltages are both referenced to pin 3
(output common). If the input voltage between pin 8 and
pin 5 is less than 6V, pin 6 should also be connected to
pin 3 as shown by the dashed line.
Paralleling for Lower Output Resistance
Additional flexibility of the LTC1044A is shown in Figures
10 and 11.
Figure 10 shows two LTC1044As connected in parallel to
provide a lower effective output resistance. If, however,
the output resistance is dominated by 1/(f • C1), increasing
the capacitor size (C1) or increasing the frequency will be
of more benefit than the paralleling circuit shown.
Figure 11 makes use of stacking two LTC1044As to pro-
vide even higher voltages. A negative voltage doubler or
tripler can be achieved, depending upon how pin 8 of the
second LTC1044A is connected, as shown schematically
by the switch. The available output current will be dictated/
decreased by the product of the individual power conver-
sion efficiencies and the voltage step-up ratio.
Figure 9. Battery Splitter
Figure 10. Paralleling for Lower Output Resistance
Figure 11. Stacking for Higher Voltage
1
2
3
4
8
7
6
5
LTC1044A
+VB/2 (6V)
+VB/2 (–6V)
OUTPUT
COMMON
+
C1
10µF
VB
12V
+
C2
10µF
REQUIRED FOR VB < 6V
1044a F09
+
1
2
3
4
8
7
6
5
LTC1044A
+
C1
10µF
1
2
3
4
8
7
6
5
LTC1044A
1/4 CD4077
1044a F10
V+
+
C1
10µF
C2
20µF
VOUT = –(V+)
+
*
*THE EXCLUSIVE NOR GATE SYNCHRONIZES BOTH LTC1044As TO MINIMIZE RIPPLE
1
2
3
4
8
7
6
5
LTC1044A
+
+
10µF
V+
–(V+)
10µF
1044a F11
10µF
1
2
3
4
8
7
6
5
LTC1044A
+
10µF
FOR VOUT = –3V+
VOUT
FOR VOUT = –2V+
+
LTC1044A
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Typical applicaTions
Low Output Impedance Voltage Converter
Single 5V Strain Gauge Bridge Signal Conditioner
LTC1044A
8
100µF
1044a F12
10µF
OUTPUT
7 6 5
1 2 3
10µF
4
+
+
+
–
+
50k
39k LM10
4
8
*VIN ≥ |–VOUT| + 0.5V
LOAD REGULATION ±0.02%, 0mA TO 15mA
1
6
8.2k
50k VOUT
ADJ
7
3
VIN*
2
200k
200k
0.1µF
39k
1
2
3
4
8
7
6
5
LTC1044A
100µF –5V
1
7
3
4 8
5V
2
5
6
100µF
0.33µF
0.1µF
0.047µF
OUTPUT
0V TO 3.5V
0psi to 350psi
–
+
–
+
+
+
2k
GAIN
TRIM
10k
ZERO
TRIM
1.2V REFERENCE TO
A/D CONVERTER FOR
RATIOMETRIC OPERATION
(1mA MAX)
LT1004
1.2V
46k*
100k
LT1413
1044a F13
220Ω
39k
301k*
350Ω PRESSURE
TRANSDUCER
*1% FILM RESISTOR
PRESSURE TRANSDUCER BLH/DHF-350
(CIRCLED LETTER IS PIN NUMBER)
100Ω*
D
A
E
0V
≈ –1.2V C
LTC1044A
11
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For more information www.linear.com/LTC1044A
Typical applicaTions
Regulated Output 3V to 5V Converter
Low Dropout 5V Regulator
1
2
3
4
8
7
6
5
LTC1044A
+
–
+
LM10
REF
AMP
1M
7
1
6
4
8
2
3
100µF
+
10µF
3V
330k
EVEREADY
EXP-30
1N914
1N914
4.8M
5V
OUTPUT
–
+
OP
AMP
200Ω
1k
1k
150k
1044a F14
100k
1
2
3
4
8
7
6
5
LTC1044A
+
10µF
12V
8
1N914
V–
V+
LT1013
2
3
4 61
7
30k
50k
OUTPUT
ADJUST
VDROPOUT AT 1mA = 1mV
VDROPOUT AT 10mA = 15mV
VDROPOUT AT 100mA = 95mV
5 FEEDBACK AMP
1N914
SHORT-CIRCUIT
PROTECTION
+10µF
200Ω
100k
1M LOAD
1044a F15
100Ω
2N2219
120k
VOUT = 5V
–
+
–
+
1.2k
LT1004
1.2V
6V
4 EVEREADY
E-91 CELLS
0.01Ω
LTC1044A
12
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For more information www.linear.com/LTC1044A
package DescripTion
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
1 2 34
87 65
.255 ±.015*
(6.477 ±0.381)
.400*
(10.160)
MAX
N8 REV I 0711
.065
(1.651)
TYP
.045 – .065
(1.143 – 1.651)
.130 ±.005
(3.302 ±0.127)
.020
(0.508)
MIN
.018 ±.003
(0.457 ±0.076)
.120
(3.048)
MIN
.008 – .015
(0.203 – 0.381)
.300 – .325
(7.620 – 8.255)
.325 +.035
–.015
+0.889
–0.381
8.255
( )
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)
.100
(2.54)
BSC
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0°– 8° TYP
.008 – .010
(0.203 – 0.254)
SO8 REV G 0212
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
1234
.150 – .157
(3.810 – 3.988)
NOTE 3
8765
.189 – .197
(4.801 – 5.004)
NOTE 3
.228 – .244
(5.791 – 6.197)
.245
MIN .160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
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)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
LTC1044A
13
1044afa
For more information www.linear.com/LTC1044A
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER
A 4/14 Changed 0.0002% to 0.002% in the Ultra-Precision Voltage Divider section 8
LTC1044A
14
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For more information www.linear.com/LTC1044A
LINEAR TECHNOLOGY CORPORATION 1993
LT 0414 REV A • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC1044A
relaTeD parTs
PART NUMBER DESCRIPTION COMMENTS
LTC3240-3.3/
LTC3240-2.5
3.3V/2.5V Step-Up/Step-Down Charge Pump
DC/DC Converter
VIN: 1.8V to 5.5V, VOUT(MAX) = 3.3V/2.5V, IQ = 65μA, ISD < 1μA,
(2mm × 2mm) DFN Package
LTC3245 Wide VIN Range Low Noise 250mA Buck-Boost
Charge Pump
VIN: 2.7V to 38V, VOUT(MAX) = 5V, IQ = 20µA, ISD = 4µA, 12-Lead MS and
(3mm × 4mm) DFN Packages
LTC3255 Wide VIN Range 50mA Buck (Step-Down)
Charge Pump
VIN: 4V to 48V, VOUT(MAX) = 12.5V, IQ = 16µA, 10-Lead MSOP and
(3mm × 3mm) DFN Packages
Typical applicaTion
1
2
3
4
8
7
6
5
LTC1044A
VIN
(1.5V TO 12V)
VOUT = 2(VIN – 1)
Vd
1N5817
Vd
1N5817
REQUIRED
FOR V+ < 3V
1044a TA02
+
+
+
+
10µF 10µF
Tw o -Diode Capacitive Voltage Doubler
