LTC1044A - 12V CMOS Voltage Converter

LTC1044A
12V CMOS
Voltage Converter
Features
Description
1.5V to 12V Operating Supply Voltage Range
n 13V Absolute Maximum Rating
n200µA Maximum No Load Supply Current at 5V
n Boost Pin (Pin 1) for Higher Switching Frequency
n97% Minimum Open Circuit Voltage Conversion
Efficiency
n95% Minimum Power Conversion Efficiency
n I = 1.5µA with 5V Supply When OSC Pin = 0V or V+
S
n High Voltage Upgrade to ICL7660/LTC1044
The LTC®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 functions without using inductors. The input voltage can be
inverted (VOUT = –VIN), doubled (VOUT = 2VIN), divided
(VOUT = VIN/2) or multiplied (VOUT = ±nVIN).
n
Applications
n
n
n
n
n
n
n
Conversion of 10V to ±10V Supplies
Conversion of 5V to ±5V Supplies
Precise Voltage Division: VOUT = VIN/2 ±20ppm
Voltage Multiplication: VOUT = ±nVIN
Supply Splitter: VOUT = ±VS/2
Automotive Applications
Battery Systems with 9V Wall Adapters/Chargers
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+.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Typical Application
Output Voltage vs Load Current, V+ = 10V
Generating –10V from 10V
0
LTC1044A
2
10µF
3
4
CAP+
V+
OSC
GND
LV
CAP–
VOUT
1044a TA01a
8
10V INPUT
6
5
–10V OUTPUT
10µF
TA = 25°C
C1 = C2 = 10µF
–2
7
OUTPUT VOLTAGE (V)
+
BOOST
+
1
–1
–3
–4
–5
–6
SLOPE = 45Ω
–7
–8
–9
–10
0
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
1044a TA01b
1044afa
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1
LTC1044A
Absolute Maximum Ratings
(Note 1)
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
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
Pin Configuration
TOP VIEW
BOOST 1
+
TOP VIEW
8
V+
8
V+
2
7
OSC
BOOST 1
CAP+
2
7
OSC
GND 3
6
LV
GND 3
6
LV
CAP– 4
5
VOUT
CAP– 4
5
VOUT
CAP
N8 PACKAGE
8-LEAD PLASTIC DIP
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 110°C, θJA = 100°C/W
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 LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC 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/
1044afa
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LTC1044A
Electrical Characteristics
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.
LTC1044AC
SYMBOL PARAMETER
IS
ROUT
CONDITIONS
MIN
LTC1044AI
TYP
MAX
60
15
200
MIN
TYP
MAX
UNITS
60
15
200
μA
μA
Supply Current
RL = ∞, Pins 1 and 7, No Connection
RL = ∞, Pins 1 and 7, No Connection,
V+ = 3V
Minimum Supply Voltage
RL = 10k
l
Maximum Supply Voltage
RL = 10k
l
12
12
V
Output Resistance
IL = 20mA, fOSC = 5kHz
V+ = 2V, IL = 3mA, fOSC = 1kHz
l
l
100
120
310
100
130
325
Ω
Ω
Ω
l
l
fOSC
Oscillator Frequency
V+ = 5V, (Note 3)
V+ = 2V
PEFF
Power Efficiency
RL = 5k, fOSC = 5kHz
Voltage Conversion Efficiency RL = ∞
Oscillator Sink or Source
Current
1.5
5
1
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
V
5
1
kHz
kHz
95
98
95
98
%
97
99.9
97
99.9
%
= 0V or V+
VOSC
Pin 1 (BOOST) = 0V
Pin 1 (BOOST) = V+
1.5
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.
1044afa
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3
LTC1044A
Typical Performance Characteristics
14
100
98
12
POWER EFFICIENCY (%)
6
4
1µF
92
IL = 1mA
90
88
100µF
86
10µF
80
100
125
IL = 15mA
OUTPUT RESISTANCE (Ω)
OUTPUT RESISTANCE (Ω)
500
C1 = C2 = 1µF
200
100
1k
10k
OSCILLATOR FREQUENCY (Hz)
300
C1 = C2 = 1µF
C1 = C2
= 100µF
200
C1 = C2
= 10µF
100
0
100
100k
1k
10k
OSCILLATOR FREQUENCY (Hz)
90
80
IS
50
40
40
30
30
20
20
10
10
10
PEFF
80
40
30
20
50
LOAD CURRENT (mA)
60
10
TA = 25°C
C1 = C2 = 10µF
fOSC = 1kHz
9
8
70
7
60
6
IS
50
5
40
4
30
3
20
2
10
1
0
0
0
1
4
3
2
5
LOAD CURRENT (mA)
6
7
1044a G06
70
0
300
270
PEFF
80
70
240
210
IS
60
180
50
150
40
120
30
90
20
TA = 25°C
C1 = C2 = 10µF
fOSC = 20kHz
10
0
1044a G07
0
20
80
60
40
100
LOAD CURRENT (mA)
120
SUPPLY CURRENT (mA)
70
POWER CONVERSION EFFICIENCY (%)
100
90
60
0
90
100k
100
SUPPLY CURRENT (mA)
POWER CONVERSION EFFICIENCY (%)
TA = 25°C
C1 = C2 = 10µF
fOSC = 5kHz
70
0
100k
Power Conversion Efficiency vs
Load Current, V+ = 10V
60
50
1k
10k
OSCILLATOR FREQUENCY (Hz)
1044a G05
100
PEFF
1µF
100
400
Power Conversion Efficiency vs
Load Current, V+ = 5V
80
1µF
Power Conversion Efficiency vs
Load Current, V+ = 2V
TA = 25°C
IL = 10mA
1044a G04
90
86
1044a G03
C1 = C2 = 100µF
0
100
88
Output Resistance vs Oscillator
Frequency, V+ = 10V
TA = 25°C
IL = 10mA
300
90
60
30
0
140
1044a G08
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SUPPLY CURRENT (mA)
400
100µF
IL = 15mA
10µF
1044a G02
Output Resistance vs Oscillator
Frequency, V+ = 5V
C1 = C2 = 10µF
10µF
80
100
100k
TA = 25°C
C1 = C2
IL = 1mA
92
82
1k
10k
OSCILLATOR FREQUENCY (Hz)
1044a G01
500
94
84
1µF
82
25
75
0
50
100
AMBIENT TEMPERATURE (°C)
100µF
96
10µF
94
84
2
98
POWER CONVERSION EFFICIENCY (%)
SUPPLY VOLTAGE (V)
8
100
TA = 25°C
C1 = C2
100µF
96
10
0
–55 –25
Power Efficiency vs Oscillator
Frequency, V+ = 10V
Power Efficiency vs Oscillator
Frequency, V+ = 5V
POWER EFFICIENCY (%)
Operating Voltage Range vs
Temperature
LTC1044A
Typical Performance Characteristics
Output Resistance vs Supply
Voltage
2.5
TA = 25°C
IL = 3mA
COSC = 0pF
1
2
3
0.5
0
SLOPE = 250Ω
– 0.5
–1.0
1
2
3 4 5 6 7 8
LOAD CURRENT (mA)
2
0
–2
–4
–6
0
320
V + = 2V, fOSC = 1kHz
280
240
200
160
120
V + = 5V, fOSC = 5kHz
80
V + = 10V, fOSC = 20kHz
0
50
25
0
75 100
–55 –25
AMBIENT TEMPERATURE (°C)
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
PIN 1 = OPEN
1
100
1000
10000
10
EXTERNAL CAPACITOR (PIN 7 TO GND)(pF)
1044a G15
100k
OSCILLATOR FREQUENCY (Hz)
PIN 1 = V +
100
10
TA = 25°C
PIN 1 = V +
10k
1k
PIN 1 = OPEN
100
10
125
1
100
1000
10000
10
EXTERNAL CAPACITOR (PIN 7 TO GND)(pF)
1044a G14
Oscillator Frequency vs Supply
Voltage
V + = 10V
TA = 25°C
1k
100k
Oscillator Frequency as a
Function of COSC, V+ = 5V
1044a G13
Oscillator Frequency as a
Function of COSC, V+ = 10V
10k
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
40
1044a G12
100k
0
1044a G11
C1 = C2 = 10µF
360
SLOPE = 45Ω
–8
–10
400
OUTPUT RESISTANCE (Ω)
OUTPUT VOLTAGE (V)
4
–5
10
Output Resistance vs
Temperature
TA = 25°C
fOSC = 20kHz
6
9
1044a G10
Output Voltage vs Load Current,
V+ = 10V
8
–2
–4
1044a G09
10
–1
–2.0
0
SLOPE = 80Ω
0
–3
–2.5
4 5 6 7 8 9 10 11 12
SUPPLY VOLTAGE (V)
2
1
–1.5
TA = 25°C
COSC = 0pF
10k
1k
0.1k
0
1
2
3
4 5 6 7 8 9 10 11 12
SUPPLY VOLTAGE (V)
1044a G16
Oscillator Frequency vs
Temperature
35
COSC = 0pF
OSCILLATOR FREQUENCY (kHz)
0
OUTPUT VOLTAGE (V)
100
3
1.0
OSCILLATOR FREQUENCY (Hz)
COSC = 100pF
TA = 25°C
fOSC = 5kHz
4
1.5
10
OSCILLATOR FREQUENCY (Hz)
5
TA = 25°C
fOSC = 1kHz
2.0
OUTPUT VOLTAGE (V)
OUTPUT RESISTANCE (Ω)
1000
Output Voltage vs Load Current,
V+ = 5V
Output Voltage vs Load Current,
V+ = 2V
30
25
V + = 10V
20
15
10
5
0
–55 –25
V + = 5V
50
100
25
75
0
AMBIENT TEMPERATURE (°C)
125
1044a G17
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5
LTC1044A
Test Circuit
V + (5V)
1
2
+
C1
10µF
IS
8
7
LTC1044A
3
4
EXTERNAL
OSCILLATOR
6
IL
RL
5
COSC
C2
10µF
VOUT
+
1044a TC
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, capacitor 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)
V1
V2
f
C1
C2
RL
1044a F01
Figure 1. Switched-Capacitor Building Block
Rewriting in terms of voltage and impedance equivalence,
I=
V1– V2 V1– V2
=
1
REQUIV
(f •C1)
A new variable, REQUIV, has been defined such that REQUIV
= 1/(f • C1). Thus, the equivalent circuit for the switchedcapacitor network is as shown in Figure 2.
V1
REQUIV
V2
C2
REQUIV =
1
f × C1
RL
1044a F02
Figure 2. Switched-Capacitor Equivalent Circuit
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.
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LTC1044A
Applications Information
V+
(8)
BOOST
+
φ
7X
(1)
÷2
OSC
OSC
(7)
φ
CLOSED WHEN
V + > 3V
LV
(6)
SW2
C+
(2)
C1
C–
(4)
VOUT
(5)
+
SW1
1044a F03
C2
GND
(3)
Figure 3. LTC1044A Switched-Capacitor Voltage Converter Block Diagram
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.
V+
6I
I
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).
BOOST
(1)
V+
NC
~14pF
LV
(6)
SCHMITT
TRIGGER
+
C1
8
2
3
7
LTC1044A
4
100k
REQUIRED FOR
TTL LOGIC
6
5
1044a F04
OSC INPUT
–(V +)
I
+
6I
OSC
(7)
1
C2
Figure 4. Oscillator
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.
Figure 5. External Clocking
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LTC1044A
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).
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.
VIN
(1.5V TO 12V)
1
8
2
3
7
LTC1044A
4
Notice that the above equation for REQUIV is not a capacitive reactance equation (XC = 1/C) and does not contain
a 2π term.
10µF
8
2
7
3
4
TMIN ≤ TA ≤ TMAX
LTC1044A
V + (1.5V TO 12V)
6
+
REQUIRED
FOR V + < 3V
Vd
1N5817
+
+
10µF
+
VOUT = 2(VIN – 1)
10µF
1044a F07
Figure 7. Voltage Doubler
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.
+
V +/2 ±0.002%
REQUIRED FOR V + < 3V
5
TMIN ≤ TA ≤ TMAX
IL ≤ 100nA
C1
10µF
+
1
8
2
7
3
LTC1044A
4
V + (3V TO 24V)
6
5
C2
10µF
REQUIRED FOR
V + < 6V
1044a F08
VOUT = – V +
+
+
1
6
5
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:
1
REQUIV =
(fOSC / 2)•C1
1
=
= 20Ω
3
5 •10 •10 •10 – 6
Vd
1N5817
10µF
Figure 8. Ultra-Precision Voltage Divider
1044a F06
Figure 6. Negative Voltage Converter
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LTC1044A
Applications Information
Battery Splitter
Paralleling for Lower Output Resistance
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 symmetrical ± 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.
Additional flexibility of the LTC1044A is shown in Figures
10 and 11.
+ C1
10µF
8
2
7
3
LTC1044A
4
6
5
Figure 11 makes use of stacking two LTC1044As to provide 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 conversion efficiencies and the voltage step-up ratio.
+VB/2 (6V)
REQUIRED FOR V B < 6V
+VB/2 (–6V)
C2
10µF
OUTPUT
COMMON
1044a F09
Figure 9. Battery Splitter
+ C1
1
8
1
2
7
2
3
10µF
V+
LTC1044A
4
+ C1
6
3
10µF
5
8
7
LTC1044A
4
6
5
V OUT = –(V + )
1/4 CD4077
+
*
C2
20µF
*THE EXCLUSIVE NOR GATE SYNCHRONIZES BOTH LTC1044As TO MINIMIZE RIPPLE
1044a F10
Figure 10. Paralleling for Lower Output Resistance
V+
10µF
8
2
7
3
4
LTC1044A
10µF
+
1
6
3
5
4
– (V + )
10µF
FOR V OUT = –2V +
8
2
7
LTC1044A
+
+
1
FOR V OUT = –3V +
6
5
V OUT
+
VB
12V
1
+
+
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.
10µF
1044a F11
Figure 11. Stacking for Higher Voltage
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9
LTC1044A
Typical Applications
Low Output Impedance Voltage Converter
200k
8.2k
VIN*
39k
2
7
+
VOUT
ADJ
50k
6
LM10
8
4
50k
200k
7
8
+
1
–
6
OUTPUT
5
100µF
+
3
LTC1044A
0.1µF
39k
10µF
1044a F12
1
2
3
4
10µF
*VIN ≥ |–VOUT| + 0.5V
LOAD REGULATION ±0.02%, 0mA TO 15mA
+
Single 5V Strain Gauge Bridge Signal Conditioner
+
100µF
1
8
2
7
LTC1044A
3
6
5 –5V
4
220Ω
5V
100µF
+
4
0.33µF
1.2V REFERENCE TO
A/D CONVERTER FOR
RATIOMETRIC OPERATION
(1mA MAX)
3
D
100k
10k
LT1004 ZERO
1.2V
TRIM
301k*
0V
*1% FILM RESISTOR
PRESSURE TRANSDUCER BLH/DHF-350
(CIRCLED LETTER IS PIN NUMBER)
+
E
1
2k
GAIN
TRIM
–
350Ω PRESSURE
TRANSDUCER
5
6
C
OUTPUT
0V TO 3.5V
0psi to 350psi
0.047µF
46k*
LT1413
A
39k
≈ –1.2V
2
8
100Ω*
+
7
–
0.1µF
1044a F13
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10
For more information www.linear.com/LTC1044A
LTC1044A
Typical Applications
Regulated Output 3V to 5V Converter
3V
200Ω
1
8
2
7
3
5V
OUTPUT
100µF
6
4
10µF
+
5
1M
4.8M
7
1k
330k
1
REF
AMP
8
–
+
LTC1044A
1N914
+
EVEREADY
EXP-30
LM10
OP
AMP
2
3
+
6
–
1k
4
1N914
100k
150k
1044a F14
Low Dropout 5V Regulator
2N2219
200Ω
+
10µF
VOUT = 5V
1N914
1
8
2
7
3
LTC1044A
4
12V
+
6
10µF
100Ω
5
120k
100k
SHORT-CIRCUIT
PROTECTION
1M
6V
4 EVEREADY
E-91 CELLS
2
8
5
FEEDBACK AMP
V+
LOAD
+
–
LT1013
3
+
7
–
V–
4
LT1004
1.2V
1
1N914
6
30k
1.2k
50k
OUTPUT
ADJUST
0.01Ω
1044a F15
VDROPOUT AT 1mA = 1mV
VDROPOUT AT 10mA = 15mV
VDROPOUT AT 100mA = 95mV
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For more information www.linear.com/LTC1044A
11
LTC1044A
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.400*
(10.160)
MAX
8
7
.300 – .325
(7.620 – 8.255)
6
5
.255 ±.015*
(6.477 ±0.381)
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
1
2
.130 ±.005
(3.302 ±0.127)
.045 – .065
(1.143 – 1.651)
4
3
(
+.035
.325 –.015
8.255
+0.889
–0.381
)
.120
(3.048) .020
MIN
(0.508)
MIN
.018 ±.003
.100
(2.54)
BSC
(0.457 ±0.076)
N8 REV I 0711
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 .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
.050 BSC
8
.245
MIN
.160 ±.005
.010 – .020
× 45°
(0.254 – 0.508)
NOTE:
1. DIMENSIONS IN
5
.150 – .157
(3.810 – 3.988)
NOTE 3
1
RECOMMENDED SOLDER PAD LAYOUT
2
.053 – .069
(1.346 – 1.752)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
6
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
.008 – .010
(0.203 – 0.254)
7
.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)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
SO8 REV G 0212
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12
For more information www.linear.com/LTC1044A
LTC1044A
Revision History
REV
DATE
DESCRIPTION
A
4/14
Changed 0.0002% to 0.002% in the Ultra-Precision Voltage Divider section
PAGE NUMBER
8
1044afa
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 information
circuits as described
herein will not infringe on existing patent rights.
For more
www.linear.com/LTC1044A
13
LTC1044A
Typical Application
Two-Diode Capacitive Voltage Doubler
VIN
(1.5V TO 12V)
1
8
2
7
LTC1044A
3
4
Vd
1N5817
6
5
+
REQUIRED
FOR V + < 3V
Vd
1N5817
+
+
10µF
+
VOUT = 2(VIN – 1)
10µF
1044a TA02
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
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14 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
For more information www.linear.com/LTC1044A
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com/LTC1044A
LT 0414 REV A • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 1993