LTC1044/7660
Switched Capacitor
Voltage Converter
FEATURES
DESCRIPTION
Plug-In Compatible with 7660 with These Additional
Features:
nn Guaranteed Operation to 9V, with No External
Diode, Over Full Temperature Range
nn Boost Pin (Pin 1) for Higher Switching Frequency
nn Lower Quiescent Power
nn Efficient Voltage Doubler
nn 200µA Max. No Load Supply Current at 5V
nn 97% Min. Open Circuit Voltage Conversion Efficiency
nn 95% Min. Power Conversion Efficiency
nn Wide Operating Supply Voltage Range, 1.5V to 9V
nn East to Use
nn Commercial Device Guaranteed Over –40°C to 85°C
Temperature Range
The LTC®1044 is a monolithic CMOS switched capacitor
voltage converter which is manufactured using Analog
Devices’ enhanced LTCMOS™ silicon gate process. The
LTC1044 provides several voltage conversion functions:
the input voltage can be inverted (VOUT = –VIN), doubled
(VOUT = 2VIN), divided (VOUT = VIN/2) or multiplied (VOUT
= ± nVIN).
nn
APPLICATIONS
Conversion of 5V to ±5V Supplies
Precise Voltage Division, VOUT = VIN/2 ±20ppm
nn Voltage Multiplication, V
OUT = ±nVIN
nn Supply Splitter, V
=
±V
OUT
S/2
nn
Designed to be pin-for-pin and functionally compatible
with the popular 7660, the LTC1044 provides significant
features and improvements over earlier 7660 designs.
These improvements include: full 1.5V to 9V supply operation over the entire operating temperature range, without
the need for external protection diodes; two and one-half
times lower quiescent current for greater power conversion efficiency; and a “boost” function which is available
to raise the internal oscillator frequency to optimize performance in specific applications.
Although the LTC1044 provides significant design and
performance advantages over the earlier 7660 device, it
still maintains its compatibility with existing 7660 designs.
nn
All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION
Generating CMOS Logic Supply from Two Mercury Batteries
Supply Current vs Supply Voltage
400
2 – 1.2V
CELLS
+ C1
10µF
2
3
4
SUPPLY CURRENT IS ≈ 3µA
4.8V
8
LTC1044
IS
7
6
5
360
VOUT
CMOS
LOGIC
NETWORK
C2
10µF
+
1044 7660 TA01a
NO LOAD INPUT CURRENT, IS (µA)
1
RL = ∞
320
280
240
200
160
GUARANTEED
POINT
120
80
TYPICAL
40
0
0
1
2
3 4 5 6 7 8
SUPPLY VOLTAGE, V+ (V)
9
10
1044/7660 TA01b
Rev. A
Document Feedback
For more information www.analog.com
1
LTC1044/7660
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
Operating Temperature Range
LTC1044C...................................... –40°C ≤ TA ≤ 85°C
LTC1044M....................................–55°C ≤ TA ≤ 125°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10sec).................... 300°C
Supply Voltage..........................................................9.5V
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+ ≤5.5V)................................................. Continuous
PIN CONFIGURATION
TOP VIEW
BOOST 1
CAP + 2
GROUND 3
CAP – 4
8 V+
7 OSC
6 LV
5 VOUT
J8 PACKAGE
8-LEAD HERMETC DIP
TOP VIEW
V +(CASE)
TOP VIEW
8 V+
BOOST 1
CAP
+
7 OSC
2
GROUND 3
CAP
–
6 LV
5 VOUT
4
N8 PACKAGE
8-LEAD PDIP
OBSOLETE PACKAGE
BOOST 1
8
CAP + 2
7 OSC
6 LV
5 VOUT
4
CAP –
H PACKAGE
8-LEAD TO-5 METAL CAN
GROUND 3
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
LTC1044CH#PBF
LTC1044MH#PBF
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC1044CH#TRPBF
Metal Can H Package
–40°C to 85°C
LTC1044MH#TRPBF
Metal Can H Package
–55°C to 125°C
OBSOLETE PACKAGE
LTC1044CJ8#PBF
LTC1044CJ8#TRPBF
8-Lead CERDIP
–40°C to 85°C
LTC1044MJ8#PBF
LTC1044MJ8#TRPBF
8-Lead CERDIP
–55°C to 125°C
LTC1044CN8#PBF
LTC1044CN8#TRPBF
8-Lead PDIP
0°C to 70°C
Contact the factory for parts specified with wider operating temperature ranges.
Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
Rev. A
2
For more information www.analog.com
LTC1044/7660
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, V+ = 5V. Test circuit Figure 1, unless otherwise specified.
LTC1044M
SYMBOL PARAMETER
CONDITIONS
MIN
LTC1044C
TYP
MAX
60
20
200
MIN
TYP
MAX
UNITS
60
20
200
μA
μA
IS
Supply Current
V+L
Minimum Supply Voltage
RL = 10k
l
V+H
Maximum Supply Voltage
RL = 10k (Note 3)
l
9
9
V
ROUT
Output Resistance
IL = 20mA, fOSC = 5kHz
V+ = 2V, IL = 3mA, fOSC = 1kHz
l
l
100
150
400
100
130
325
Ω
Ω
Ω
COSC = 1pF (Note 4)
V+ = 5V
V+ = 2V
l
l
fOSC
Oscillator Frequency
RL = ∞, Pins 1 and 7 No Connection
RL = ∞, Pins 1 and 7 V+ = 3V
PEFF
Power Efficiency
VOUTEFF
Voltage Conversion Efficiency RL = ∞
IOSC
Oscillator Sink or Source
Current
RL = 5kΩ, fOSC = 5kHz
= 0V or V+
VOSC
Pin 1 = 0V
Pin 1 = V+
l
l
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 latch-up. It is recommended that no
inputs from sources operating from external supplies be applied prior to
power-up of the LTC1044.
1.5
1.5
5
1
V
5
1
kHz
kHz
95
98
95
98
%
97
99.9
97
99.9
%
3
20
3
20
µA
µA
Note 3: The LTC1044 is guaranteed to operate with alkaline, mercury or
NiCad 9V batteries, even though the initial battery voltage may be slightly
higher than 9V.
Note 4: fOSC is tested with COSC = 100pF to minimize the effects of test
fixture capacitance loading. The 1pF 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.
Rev. A
For more information www.analog.com
3
LTC1044/7660
TYPICAL PERFORMANCE CHARACTERISTICS
Power Efficiency vs Oscillator
Frequency
98
8
96
POWER EFFICIENCY, PEFF (%)
100
9
7
6
5
4
3
2
100µF
10µF
94
1µF
92
IL = 1mA
90
88
100µF
86
84
10µF
IL = 15mA
1µF
1
82
0
–55 –25
25
75
0
50
100
AMBIENT TEMPERATURE, TA (°C)
80
100
125
8
1k
10k
OSCILLATOR FREQUENCY, fOSC (Hz)
7
6
IS
50
5
40
4
30
3
20
2
10
1
0
0
4
3
2
5
LOAD CURRENT, IL (mA)
1
7
6
0
100
90
PEFF
80
30
30
20
20
10
10
0
0
10
40
30
20
50
LOAD CURRENT, IL (mA)
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
–1
–2
–4
–2.5
–5
10
1044 7660 G07
SLOPE = 80Ω
0
–2.0
9
0
1
–3
3 4 5 6 7 8
LOAD CURRENT, IL (mA)
70
2
–1.5
2
60
TA = 25°C
V+ = 5V
fOSC = 5kHz
3
–1.0
1
50
40
4
SLOPE = 250Ω
0
60
40
5
0.5
– 0.5
80
IS
50
1000
100k
TA = 25°C
IL = 3mA
90
COSC = 100pF
100
10
COSC = 0pF
0
1
2
7 8
3 4 5 6
SUPPLY VOLTAGE, V+ (V)
10
9
1044 7660 G06
Output Voltage vs Load Current
for V+ = 5V
1.0
0
100
V+ = 5V
TA = 25°C
C1 = C2 = 10µF
fOSC = 5kHz
1044 7660 G05
TA = 25°C
V+ = 2V
fOSC = 1kHz
1.5
1k
10k
OSCILLATOR FREQUENCY, fOSC (Hz)
1044 7660 G03
70
60
Output Voltage vs Load Current
for V+ = 2V
2.0
100
Output Resistance vs Supply
Voltage
70
1044 7660 G04
2.5
100k
SUPPLY CURRENT (mA)
70
60
200
0
100
OUTPUT RESISTANCE, RO (Ω)
9
POWER CONVERSION EFFICIENCY, PEFF (%)
80
10
SUPPLY CURRENT (mA)
POWER CONVERSION EFFICIENCY, PEFF (%)
PEFF
C1 = C2 = 1µF
300
Power Conversion Efficiency vs
Load Current for V+ = 5V
V+ = 2V
TA = 25°C
C1 = C2 = 10µF
fOSC = 1kHz
C1 = C2 = 10µF
400
1044 7660 G02
Power Conversion Efficiency vs
Load Current for V+ = 2V
90
TA = 25°C
V+ = 5V
IL = 10mA
C1 = C2 = 100µF
1044 7660 G01
100
500
V+ = 5V
TA = 25°C
C1 = C2
Output Resistance vs
Temperature
400
C1 = C2 = 10µF
360
OUTPUT RESISTANCE (Ω)
SUPPLY VOLTAGE, V+ (V)
10
Output Resistance vs Oscillator
Frequency
OUTPUT RESISTANCE, RO (Ω)
Operating Voltage Range vs
Temperature
(Using Test Circuit Shown in Figure 1)
320
280
V+ = 2V
fOSC = 1kHz
240
200
160
120
V+ = 5V
fOSC = 5kHz
80
40
0
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT, IL (mA)
1044 7660 G08
0
–55
–25
0
50
75 100
25
AMBIENT TEMPERATURE (°C)
125
1044 7660 G09
Rev. A
4
For more information www.analog.com
LTC1044/7660
TYPICAL PERFORMANCE CHARACTERISTICS
Oscillator Frequency vs Supply
Voltage
100k
PIN 1 = V+
10k
1k
PIN 1 = OPEN
100
10
1
10
100
1k
10k
EXTERNAL CAPACITOR (PIN 7 TO GROUND), COSC (pF)
Oscillator Frequency vs
Temperature
15
COSC = 0pF
TA = 25°C
OSCILLATOR FREQUENCY, fOSC (kHz)
V+ = 5V
TA = 25°C
OSCILLATOR FREQUENCY, fOSC (Hz)
OSCILLATOR FREQUENCY, fOSC (Hz)
100k
Oscillator Frequency as a
Function of COSC
(Using Test Circuit Shown in Figure 1)
10k
1k
0.1k
0
1
2
3 4 5 6 7 8
SUPPLY VOLTAGE, V+ (V)
9
V+ = 5V
COSC = 0
14
13
12
11
10
9
8
7
6
5
–55
10
–25
0
25
50
75 100
AMBIENT TEMPERATURE (°C)
1044 7660 G11
1044 7660 G10
125
1044 7660 G12
TEST CIRCUIT
V + (5V)
IS
1
2
C1
10µF
3
4
8
LTC1044
EXTERNAL
OSCILLATOR
7
6
5
IL
RL
– C2
COSC
+
VOUT
10µF
1044 7660 F01
Figure 1
APPLICATIONS INFORMATION
Theory of Operation
To understand the theory of operation of the LTC1044,
a review of a basic switched capacitor building block is
helpful.
In Figure 2, 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:
If the switch is cycled f times per second, the charge
transfer per unit time (i.e., current) is:
l = f × ∆q = f × C1(V1 – V2).
V1
V2
f
C1
C2
RL
1044 7660 F02
Figure 2. Switched Capacitor Building Block
∆q = q1 – q2 = C1(V1 – V2).
Rev. A
For more information www.analog.com
5
LTC1044/7660
APPLICATIONS INFORMATION
Rewriting in terms of voltage and impedance equivalence,
I=
V1 – V 2
(1 / fC1)
=
V1 – V 2
REQUIV
A new variable, REQUIV, has been defined such that REQUIV
= 1/fC1. Thus, the equivalent circuit for the switched
capacitor network is as shown in Figure 3.
V1
REQUIV
REQUIV = 1
fC1
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.
V2
C2
RL
1044 7660 F03
Figure 3. Switched Capacitor Equivalent Circuit
Examination of Figure 4 shows that the LTC1044 has
the same switching action as the basic switched capacitor building block. With the addition of finite switch onresistance and output voltage ripple, the simple theory,
although not exact, provides an intuitive feel for how the
device works.
V+
(8)
φ
OSC
The internal logic of the LTC1044 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.
SW2
CAP +
(2)
+
C1
+2
φ
OSC
(7)
LV (Pin 6)
SW1
BOOST
7x
(1)
For example, if you examine power conversion efficiency
as a function of frequency (see typical curve), this simple
theory will explain how the LTC1044 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/fC1 term and power efficiency will drop. The typical curves for power efficiency
versus frequency show this effect for various capacitor
values.
CAP –
(4)
VOUT
(5)
+
LV
(6)
CLOSED WHEN
V + > 3.0V
GND
(3)
C2
1044 7660 F04
Figure 4. LTC1044 Switched Capacitor Voltage Converter Block Diagram
Rev. A
6
For more information www.analog.com
LTC1044/7660
APPLICATIONS INFORMATION
OSC (Pin 7) and Boost (Pin 1)
External Diode (Dx)
The switching frequency can be raised, lowered or driven
from an external source. Figure 5 shows a functional diagram of the oscillator circuit.
Previous circuits of this type have required a diode
between VOUT (pin 5) and the external capacitor, C2, for
voltages above 6.5V (5V for military temperature range).
Because of improvements which have been made in the
LTC1044 circuit design and Analog Devices’ silicon gate
CMOS process, this diode is no longer required. The
LTC1044 will operate from 1.5V to 9V, without the protection diode, over all temperature ranges.
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 loads currents.
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.
It should, however, be noted that the LTC1044 will operate
without any problems in existing 7660 designs which use
the protection diode, as long as the maximum operating
voltage (V+) of 9V is not exceeded.
Driving the LTC1044 from an external frequency source
can be easily achieved by driving pin 7 and leaving the
boost pin open, as shown in Figure 6. 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 5. For 5V applications, a TTL logic gate can be
used by simply adding an external pull-up resistor (see
Figure 6).
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.
REQUIRED FOR TTL LOGIC
V+
C1
6I
NC
1
8
+
2
7
3
4
I
LTC1044
V+
100k
OSC INPUT
6
–(V +)
5
C2
BOOST
(1)
1044 7660 F06
Figure 6. External Clocking
OSC
(7)
SCHMITT
TRIGGER
~14pF
6I
I
LV
(6)
1044 7660 F05
Figure 5. Oscillator
Rev. A
For more information www.analog.com
7
LTC1044/7660
TYPICAL APPLICATIONS
Negative Voltage Converter
Figure 7 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) and 2) a term related to the onresistance 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 capacitive reaction equation (XC = 1wC) and does not contain
a 2p term.
The exact expression for output impedance is extremely
complex, but the dominant effect of the capacitor is clearly
shown on the typical curves of output impedance and
power efficiency versus frequency. For C1 = C2 = 10µF,
the output impedance goes from 60Ω at fOSC = 10kHz
to 200Ω at fOSC = 1kHz. As the 1/fC term becomes large
compared to the switch on-resistance term, the output
resistance is determined by 1/fC only.
Voltage Doubling
Figure 8. shows two methods of voltage doubling. In Figure 8a
doubling is achieved by simply rearranging the connection of the two external capacitors. When the input voltage
is less than 3V, an external 1MΩ resistor is required to
ensure the oscillator will start. It is not required for higher
input voltages.
In this application the ground input (pin 3) is taken above
V+ (pin 8 ) during turn-on, making it prone to latch-up.
The latch-up is not destructive but simply prevents the
circuit form doubling. Resistor R1 is added to eliminate
the problem. In most cases 200Ω is sufficient. It may be
necessary in a particular application to increase this value
to guarantee start-up.
1
10µF
2
+
3
V+
1.5V TO 9V
8
LTC1044
7
6
5
4
TMIN ≤ TA ≤ TMAX
REQUIRED FOR V + < 3V
–
10µF
+
VOUT = –V +
1044 7660 F07
Figure 7. Negative Voltage Converter
VIN (1.5V TO 9V)
IN914
R1
200Ω
IOUT
1
+ C1
10µF
2
3
2VIN (3V TO 18V)
8
LTC1044
6
5
4
(a)
+ C2
7
10µF
1MΩ
1
2
3
4
REQUIRED
FOR
V + < 3V
8
LTC1044
VD
7
6
5
VIN
1.5V TO 9V
+
REQUIRED
FOR
V + < 3V
(b)
–
+
+
VD
10µF
–
VOUT = 2(VIN – 1)
+
10µF
1044 7660 F08
Figure 8. Voltage Doubler
Rev. A
8
For more information www.analog.com
LTC1044/7660
TYPICAL APPLICATIONS
The voltage drop across R1 is: VR1 = 2 × IOUT × R1. If this
voltage exceeds two diode drops (1.4V for silicon, 0.8V
for Schottky), the circuit in Figure 8a is recommended.
This circuit will never have a start-up problem.
Ultra Precision Voltage Divider
An ultra precision voltage divider is shown in Figure 9. To
achieve the 0.0002% accuracy indicated, the load current
should be kept below 100nA. However, with a slight loss
in accuracy, the load current can be increased.
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 10 is a simple solution. It provides symmetrical ± output voltages, both equal to one half the 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
Figure 11 shows two LTC1044s connected in parallel to
provide a lower effective output resistance. If, however,
the output resistance is dominated by 1/fC1, increasing
the capacitor size (C1) or increasing the frequency will be
of more benefit than the paralleling circuit shown.
Figures 12 and 13 make use of “stacking” two LTC1044s
to provide even higher voltages. In Figure 12, a negative voltage doubler or tripler can be achieved, depending
upon how pin 8 of the second LTC1044 is connected, as
shown schematically by the switch. Figure 13 indicates
a similar circuit which can be used to obtain positive tripling, or even quadrupling (the doubler circuit appears in
Figure 8a). In both of these circuits, the available output
current will be dictated/decreased by the product of the
individual power conversion efficiencies and the voltage
step-up ratio.
VB
9V
+
–
1
C1
10µF
+
2
–
3
+VB /2 (4.5V)
8
LTC1044
4
Additional flexibility of the LTC1044 is shown in Figures
11, 12 and 13.
7
6
REQUIRED FOR VB < 6V
–VB /2 (–4.5V)
5
– C2
10µF
+
3V ≤ VB ≤ 18V
1
2
C1 +
3
10µF
4
V+
±0.002%
2
TMIN ≤ TA ≤ TMAX
IL ≤ 100nA
+
8
LTC1044
OUTPUT COMM0N
1044 7660 F10
V+
3V TO 18V
7
Figure 10. Battery Splitter
6
5
1044 7660 F09
C2
10µF
REQUIRED FOR V + < 6V
Figure 9. Ultra Precision Voltage Divider
Rev. A
For more information www.analog.com
9
LTC1044/7660
TYPICAL APPLICATIONS
V+
1
C1
10µF
2
+
1
8
7
LTC1044
3
6
2
+
C1
10µF
7
LTC1044
3
5
4
8
6
VOUT = –(V +)
5
4
1/4 CD4077
+
*
C2
20µF
1044 7660 F11
*THE EXCLUSIVE NOR GATE SYNCHRONIZES BOTH LTC1044s TO MINIMIZE RIPPLE
Figure 11. Paralleling for Lower Output Resistance
FOR VOUT = –3V +
V+
+
8
2
7
3
LTC1044
1
10µF
+
6
8
2
LTC1044
2
3
–(V +)
5
4
1
7
6
5
4
VOUT
10µF
+
10µF
1
FOR VOUT = –2V +
10µF
+
1044 7660 F12
Figure 12. Stacking for Higher Voltage
1N914
V+ (+5V)
1N914
10µF
+
2
3
8
LTC1044
1
4
7
6
5
200Ω
(+10V)
2V+
+
1
+
1
8
2
7
LTC1044
2
3
6
5
4
VOUT
+
10µF
200Ω
10µF
1M*
10µF
1M*
FOR VOUT = 3V +
(+15V)
*REQUIRED FOR V+ < 3V
FOR VOUT = 4V +
(+20V)
1044 7660 F13
Figure 13. Voltage Tripler/Quadrupler
Rev. A
10
For more information www.analog.com
LTC1044/7660
TYPICAL APPLICATIONS
200k
8.2k
39k
2
7
+
50k
6
LM10
VOUT
ADJ
+
1
–
8
4
50k
200k
OUTPUT
8
100µF
7
6
5
+
3
–
VIN*
10µF
LTC1044
0.1µF
39k
1
2
VIN ≥ |–VOUT| + 0.5V
LOAD REGULATION ±0.02%, 0mA TO 15mA
3
4
10µF
+
1044 7660 F14
Figure 14. Low Output Impedance Voltage Converter
1
+
2
100µF
3
220Ω
5V
8
LTC1044
7
6
–5V
5
4
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*
LT1013
A
39k
≈ –1.2V
2
8
100Ω*
+
7
–
0.1µF
1044 7660 F15
Figure 15. Single 5V Strain Gauge Bridge Signal Conditioner
Rev. A
For more information www.analog.com
11
LTC1044/7660
TYPICAL APPLICATIONS
3V
1N914
1
8
2
+
7
LTC1044
3
6
5
4
10µF
1k
330k
+
5V
OUTPUT
100µF
1M
4.8M
7
1
REF
AMP
8
–
200Ω
+
EVEREADY
EXP-30
LM10
OP
AMP
2
3
+
6
–
1k
4
1N914
100k
150k
1044 7660 F16
Figure 16. Regulated Output 3V to 5V Converter
2N2219
200Ω
+
1N914
1
2
10µF
VOUT = 5V
3
+12V
8
LTC1044
+
7
6
10µF
100Ω
120k
5
4
100k
SHORT-CIRCUIT
PROTECTION
1M
4 EVEREADY
E-91 CELLS
6V
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
1044 7660 F17
VDROPOUT AT 1mA = 1mV
VDROPOUT AT 10mA = 15mV
VDROPOUT AT 100mA = 95mV
Figure 17. Low Dropout 5V Regulator
Rev. A
12
For more information www.analog.com
LTC1044/7660
PACKAGE DESCRIPTION
H Package
8-Lead TO-5 Metal Can (.230 Inch PCD)
(Reference LTC DWG # 05-08-1321)
.040
(1.016)
MAX
.335 – .370
(8.509 – 9.398)
DIA
.305 – .335
(7.747 – 8.509)
.050
(1.270)
MAX
SEATING
PLANE
.165 – .185
(4.191 – 4.699)
GAUGE
PLANE
.010 – .045*
(0.254 – 1.143)
REFERENCE
PLANE
.500 – .750
(12.700 – 19.050)
.016 – .021**
(0.406 – 0.533)
.027 – .045
(0.686 – 1.143)
45°
.028 – .034
(0.711 – 0.864)
PIN 1
.230
(5.842)
TYP
.110 – .160
(2.794 – 4.064)
INSULATING
STANDOFF
*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) H8 (TO-5) 0.230 PCD 0204
Rev. A
Document Feedback
For more information www.analog.com
13
LTC1044/7660
PACKAGE DESCRIPTION
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
.005
(0.127)
MIN
.405
(10.287)
MAX
8
7
6
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.300 BSC
(7.62 BSC)
2
3
4
.200
(5.080)
MAX
.015 – .060
(0.381 – 1.524)
.008 – .018
(0.203 – 0.457)
0° – 15°
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.045 – .065
(1.143 – 1.651)
.014 – .026
(0.360 – 0.660)
.100
(2.54)
BSC
.125
3.175
MIN
J8 0801
OBSOLETE PACKAGE
Rev. A
14
05/19
www.analog.com
For more information www.analog.com
ANALOG DEVICES, INC. 2019
LTC1044/7660
REVISION HISTORY
REV
DATE
DESCRIPTION
A
05/19
Obsolete CERDIP package
PAGE NUMBER
2, 14
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license For
is granted
implication or
otherwise under any patent or patent rights of Analog Devices.
more by
information
www.analog.com
15
LTC1044/7660
PACKAGE DESCRIPTION
N Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510 Rev I)
.400*
(10.160)
MAX
8
7
6
5
1
2
3
4
.255 ±.015*
(6.477 ±0.381)
.300 – .325
(7.620 – 8.255)
.008 – .015
(0.203 – 0.381)
(
+.035
.325 –.015
8.255
+0.889
–0.381
)
.045 – .065
(1.143 – 1.651)
.065
(1.651)
TYP
.100
(2.54)
BSC
.130 ±.005
(3.302 ±0.127)
.120
(3.048) .020
MIN
(0.508)
MIN
.018 ±.003
(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)
Rev. A
16
05/19
www.analog.com
For more information www.analog.com
ANALOG DEVICES, INC. 2019
工商网监
湘ICP备2023018690号
