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LTC660 100mA CMOS Voltage Converter
FEATURES
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DESCRIPTION
The LTC(R)660 is a monolithic CMOS switched-capacitor voltage converter. It performs supply voltage conversion from positive to negative from an input range of 1.5V to 5.5V, resulting in complementary output voltages of - 1.5V to - 5.5V. It also performs a doubling at an input voltage range of 2.5V to 5.5V, resulting in a doubled output voltage of 5V to 11V. Only two external capacitors are needed for the charge pump and charge reservoir functions. The converter has an internal oscillator that can be overdriven by an external clock or slowed down when connected to a capacitor. The oscillator runs at a 10kHz frequency when unloaded. A higher frequency outside the audio band can also be obtained if the BOOST pin is tied to V +. The LTC660 contains an internal oscillator, divide-by-two, voltage level shifter and four power MOSFETs.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Simple Conversion of 5V to - 5V Supply Output Drive: 100mA ROUT: 6.5 (0.65V Loss at 100mA) BOOST Pin (Pin 1) for Higher Switching Frequency Inverting and Doubling Modes Minimum Open Circuit Voltage Conversion Efficiency: 99% Typical Power Conversion Efficiency with a 100mA Load: 88% Easy to Use
APPLICATIONS
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Conversion of 5V to 5V Supplies Inexpensive Negative Supplies Data Acquisition Systems High Current Upgrade to LTC1044 or LTC7660
TYPICAL APPLICATION
Generating - 5V from 5V
1 2 BOOST CAP
+
Output Voltage vs Load Current for V + = 5V
-5.0
5V INPUT
V+ OSC LV VOUT
8 7
GND CAP
-
4
5
OUTPUT VOLTAGE (V)
+
C1 150F
3
LTC660
-4.8
6 -5V OUTPUT
-4.6
C2 150F
-4.4
660 TA01
-4.2
-4.0 0 20 60 80 40 LOAD CURRENT (mA) 100
660 TA02
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+
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TA = 25C ROUT = 6.5
1
LTC660
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
TOP VIEW BOOST 1 CAP
+
Supply Voltage (V +) .................................................. 6V Input Voltage on Pins 1, 6, 7 (Note 2) ............................ - 0.3V < VIN < (V + + 0.3V) Output Short-Circuit Duration to GND (Note 5) ............................................................. 1 sec Power Dissipation.............................................. 500mW Operating Temperature Range .................... 0C to 70C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER
8 V+ 7 OSC 6 LV 5 VOUT
2
GND 3 CAP - 4
LTC660CN8 LTC660CS8 S8 PART MARKING 660
N8 PACKAGE 8-LEAD PLASTIC DIP S8 PACKAGE 8-LEAD PLASTIC SOIC
TJMAX = 100C, JA = 100C/W (N) TJMAX = 100C, JA = 150C/W (S)
Consult Factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
V + = 5V, C1 and C2 = 150F, Boost = Open, COSC = 0pF, TA = 25C, unless otherwise noted.
SYMBOL PARAMETER Supply Voltage CONDITIONS RL = 1k Inverter, LV = Open Inverter, LV = GND Doubler, LV = VOUT Boost = Open Boost = V +
q q q q q q q
MIN 3 1.5 2.5
TYP
MAX 5.5 5.5 5.5
UNITS V V V mA mA mA kHz kHz % % % % A A
IS IOUT ROUT fOSC
Supply Current Output Current Output Resistance Oscillator Frequency Power Efficiency
No Load
0.08 0.23 100 6.5 10 80
0.5 3 10
VOUT More Negative Than - 4V IL = 100mA (Note 3) Boost = Open Boost = V + (Note 4) RL = 1k Connected Between V + and VOUT RL = 500 Connected Between VOUT and GND IL = 100mA to GND No Load Boost = Open Boost = V +
q q
96 92 99
98 96 88 99.96 1.1 5.0
Voltage Conversion Efficiency Oscillator Sink or Source Current
The q denotes specifications which apply over the full operating temperature range; all other limits and typicals are at TA = 25C. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 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 source operating from external supplies be applied prior to power-up of the LTC660. Note 3: The output resistance is a combination of internal switch resistance and external capacitor ESR. To maximize output voltage and efficiency, keep external capacitor ESR < 0.2.
Note 4: 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. Note 5: OUT may be shorted to GND for 1 sec without damage, but shorting OUT to V + may damage the device and should be avoided. Also, for temperatures above 85C, OUT must not be shorted to GND or V +, even instantaneously, or device damage may result.
2
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WW
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LTC660 TYPICAL PERFORMANCE CHARACTERISTICS (Using Test Circuit in Figure 1)
Supply Current vs Supply Voltage
300 TA = 25C 250
SUPPLY CURRENT (A)
SUPPLY CURRENT (A)
OUTPUT RESISTANCE ()
200 150 BOOST = V + 100 BOOST = OPEN 50 0 1.5
2
4 4.5 2.5 3 3.5 SUPPLY VOLTAGE (V)
Output Resistance vs Supply Voltage
18 16
25
TA = 25C BOOST = OPEN
OUTPUT RESISTANCE ()
OUTPUT RESISTANCE ()
14 12 10 8 6 4 2 0 0 1 3 4 2 SUPPLY VOLTAGE (V) 5 6
OUTPUT VOLTAGE (V)
Efficiency vs Load Current
100 95 90 TA = 25C BOOST = OPEN V + = 5.5V 100 95 90
OUTPUT VOLTAGE DROP FROM SUPPLY VOLTAGE (V)
EFFICIENCY (%)
EFFICIENCY (%)
85 80 75 70 V + = 1.5V 65 60 0
V + = 2.5V
10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
LTC660 * TPC07
UW
5
LTC660 * G01 LTC690 * TPC04
Supply Current vs Oscillator Frequency
1000 TA = 25C V + = 5V
100 90 80 70 60 50 40 30 20 10 5.5
Output Resistance vs Oscillator Frequency
TA = 25C V + = 5V BOOST = OPEN
100
C1 = C2 = 150F C1 = C2 = 1500F C1 = C2 = 22F
10
1 0.01
0.1 100 1 10 OSCILLATOR FREQUENCY (kHz)
1000
0 0.1
1 10 OSCILLATOR FREQUENCY (kHz)
100
LTC660 * G02
LTC660 * TPC03
Output Resistance vs Temperature
-3.0
BOOST = OPEN 20 V + = 1.5V 15 V + = 3V 10 V + = 5V 5
Output Voltage and Efficiency vs Load Current, V + = 5V
100 TA = 25C BOOST = OPEN -3.4 LTC660 EFFICIENCY 96 92 88 84 80 -4.2 LTC660 OUTPUT VOLTAGE 76 72 68 64
EFFICIENCY (%)
-3.8
-4.6
0 -60 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C)
LTC660 * TPC05
-5.0
0
60 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
LTC660 * TPC06
Efficiency vs Load Current
TA = 25C BOOST = V + V + = 5.5V 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
LTC660 * TPC08
Output Voltage Drop vs Load Current
TA = 25C BOOST = OPEN V + = 2.5V V = 1.5V
+
V + = 4.5V V + = 3.5V
85 80 75 70 65 60 V + = 1.5V
+
V + = 4.5V V + = 3.5V
V = 2.5V
V + = 3.5V V + = 4.5V V + = 5.5V
0
10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
LTC660 * TPC09
3
LTC660 TYPICAL PERFORMANCE CHARACTERISTICS (Using Test Circuit in Figure 1)
Output Voltage Drop vs Load Current
1.0 0.9 TA = 25C BOOST = V +
OUTPUT VOLTAGE DROP FROM SUPPLY VOLTAGE (V)
0.8
OUTPUT VOLTAGE (V)
0.6 0.5 0.4 0.3 0.2 0.1 0 0 V + = 1.5V
V + = 2.5V
EFFICIENCY (%)
0.7
V + = 5.5V
10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
LTC660 * TPC10
Oscillator Frequency vs Supply Voltage
12 TA = 25C BOOST = OPEN OSC = OPEN
OSCILLATOR FREQUENCY (kHz)
OSCILLATOR FREQUENCY (kHz)
8 6 4 2 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V)
LTC660 * TPC13
70 60 50 40 30 20 10 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V)
LTC660 * TPC14
OSCILLATOR FREQUENCY (kHz)
10
Oscillator Frequency vs Temperature
100 90
100
OSCILLATOR FREQUENCY (kHz)
OSCILLATOR FREQUENCY (kHz)
80 70 60 50 40 30 20 10 V+ = 5V BOOST = V+ OSC = OPEN
0 -60 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C)
LTC660 * TPC16
4
UW
V + = 3.5V V + = 4.5V
Output Voltage vs Oscillator Frequency
-5.0 IL = 1mA -4.5 IL = 10mA -4.0 IL = 80mA -3.5 100 95 90 85 80 75 70 65 -3.0 TA =25C V+ = 5V BOOST = OPEN 0.1 1 10 OSCILLATOR FREQUENCY (kHz) 100 60 55
Efficiency vs Oscillator Frequency
IL = 10mA
IL = 80mA IL = 1mA
-2.5
50 0.1
TA = 25C V+ = 5V BOOST = OPEN 1 10 OSCILLATOR FREQUENCY (kHz) 100
LTC660 * TPC11
LTC660 * TPC12
Oscillator Frequency vs Supply Voltage
100 TA = 25C 90 BOOST = V+ OSC = OPEN 80
12 10 8 6 4 2
Oscillator Frequency vs Temperature
V+ = 5V BOOST = OPEN OSC = OPEN
0 -60 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C)
LTC660 * TPC15
Oscillator Frequency vs External Capacitance
10
BOOST = V +
1
0.1
BOOST = OPEN
00.1 1 10 100 1000 CAPACITANCE (pF) 10000
LTC660 * TPC17
LTC660
PIN FUNCTIONS
PIN 1 NAME BOOST INVERTER Internal Oscillator Frequency Control Pin. BOOST = Open, fOSC = 10kHz typ; BOOST = V +, fOSC = 80kHz typ; when OSC is driven externally BOOST has no effect. Positive Terminal for Charge Pump Capacitor Power Supply Ground Input Negative Terminal for Charge Pump Capacitor Negative Voltage Output Tie LV to GND when the input voltage is less than 3V. LV may be connected to GND or left open for input voltages above 3V. Connect LV to GND when overdriving OSC. An external capacitor can be connected to this pin to slow the oscillator frequency. Keep stray capacitance to a minimum. An external oscillator can be applied to this pin to overdrive the internal oscillator. Positive Voltage Input DOUBLER Same
2 3 4 5 6
CAP + GND CAP - VOUT LV
7
OSC
8
V+
TEST CIRCUIT
V+ 1 2 LTC660 8 7 6 5 IS V+ 5V COSC RL IL C1 150F VOUT
LTC660 * F01
Figure 1. Test Circuit
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Same Positive Voltage Input Same Power Supply Ground Input LV must be tied to VOUT for all input voltages.
Same except standard logic levels will not be able to overdrive OSC pin.
Positive Voltage Output
+
C1 150F
3 4
EXTERNAL OSCILLATOR
5
LTC660
APPLICATIONS INFORMATION
Theory of Operation To understand the theory of operation for the LTC660, 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 discharging 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) Rewriting in terms of voltage and impedance equivalence,
BOOST 4.5x (1) OSC OSC (7) +2 CAP - (4) VOUT (5) C2 LV (6) GND (3) V+ (8) SW1 CAP+ (2) SW2
CLOSED WHEN V+ > 3.0V
LTC660 * F04
Figure 4. LTC660 Switched-Capacitor Voltage Converter Block Diagram
I=
V1 - V2 V1 - V2 = 1/ fC1 REQUIV
A new variable REQUIV has been defined such that REQUIV = 1/fC1. Thus, the equivalent circuit for the switchedcapacitor network is as shown in Figure 3. Figure 4 shows that the LTC660 has the same switching action as the basic switched-capacitor building block.
V1 V2
This simplified circuit does not include finite on-resistance of the switches and output voltage ripple, however, it does give an intuitive feel for how the device works. For example, if you examine power conversion efficiency as a function of frequency this simple theory will explain how the LTC660 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 voltage losses will rise decreasing the efficiency. As the frequency increases the quiescent current increases. At high frequency this current loss becomes significant and the power efficiency starts to decrease. The LTC660 oscillator frequency is designed to run where the voltage loss is a minimum. With the external 150F capacitors the effective output impedance is determined by the internal switch resistances and the capacitor ESRs. LV (Pin 6) The internal logic of the LTC660 runs between V + and LV (Pin 6). For V + 3V, an internal switch shorts LV to ground (Pin 3). For V + < 3V, the LV pin should be tied to ground. For V + 3V, the LV pin can be tied to ground or left floating. OSC (Pin 7) and BOOST (Pin 1)
C1
C2
RL
660 F02
Figure 2. Switched-Capacitor Building Block
REQUIV V1 V2
C2
RL
1 REQUIV = fC1
660 F03
Figure 3. Switched-Capacitor Equivalent Circuit
The switching frequency can be raised, lowered or driven from an external source. Figure 5 shows a functional diagram of the oscillator circuit.
6
+
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+
C1
LTC660
APPLICATIONS INFORMATION
V+
7.0I BOOST (1)
I
OSC (7) 18pF 7.0I LV (6) I
SCHMITT TRIGGER
Figure 6. External Clocking
LTC660 * F05
Capacitor Selection While the exact values of C1 and C2 are noncritical, good quality, low ESR capacitors are necessary to minimize voltage losses at high currents. For C1 the effect of the ESR of the capacitor will be multiplied by four, due to the fact the switch currents are approximately two times higher than the output current and losses will occur on both the charge and discharge cycle. This means using a capacitor with 1 of ESR for C1 will have the same effect as increasing the output impedance of the LTC660 by 4. This represents a significant increase in the voltage losses. For C2 the effect of ESR is less dramatic. A C2 with 1 of ESR will increase the output impedance by 1. The size of C2 and the load current will determine the output voltage ripple. It is alternately charged and discharged at a current approximately equal to the output current. This will cause a step function to occur in the output voltage at the switch transitions. For example, for a switching frequency of 5kHz (one-half the nominal 10kHz oscillator frequency) and C2 = 150F with an ESR of 0.2, ripple is approximately 90mV with a 100mA load current.
Figure 5. Oscillator
By connecting the BOOST pin (Pin 1) to V +, the charge and discharge current is increased and, hence, the frequency is increased by approximately four and a half times. Increasing the frequency will decrease output impedance and ripple for high load 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. Driving the LTC660 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 1.1A to 8A, so a logic gate is capable of driving this current. (A CMOS logic gate can be used to drive the OSC pin.) For 5V applications, a TTL logic gate can be used by simply adding an external pull-up resistor (see Figure 6).
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REQUIRED FOR TTL LOGIC 1 2 8 7 LTC660 6 5 C2 -(V +)
V+
NC
100k OSC INPUT
+
C1
3 4
LTC660 * F06
7
LTC660
TYPICAL APPLICATIONS N
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.
1 2 BOOST V+ 8 VIN 1.5V TO 5.5V 7 CAP+ OSC LTC660 6 3 GND LV 4 CAP - VOUT 5 VOUT = -VIN C2 150F
LTC660 * F07
+
C1 150F
Figure 7. Voltage Inverter
The output voltage (Pin 5) characteristics of the circuit are those of a nearly ideal voltage source in series with a 6.5 resistor. The 6.5 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 = 150F, the first term is:
R EQUIV =
(f
1
OSC /2 C1
)
= = 1.3.
1 5 * 103 * 150 * 10 -6
Notice that the equation for REQUIV is not a capacitive reactance equation (XC = 1/C) and does not contain a 2 term. The exact expression for output impedance is 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 = 150F, the output impedance goes from 6.5 at fOSC = 10kHz to 110 at fOSC = 100Hz. As the 1/fC term becomes large compared to the switch on-resistance term, the output resistance is determined by 1/fC only.
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Voltage Doubling Figure 8 shows the LTC660 operating in the voltage doubling mode. The external Schottky (1N5817) diode is for start-up only. The output voltage is 2 * VIN without a load. The diode has no effect on the output voltage.
1N5817*
1
BOOST CAP
+
V+ OSC LV VOUT
8 7 6 5
VIN 2.5V TO 5.5V
C1 150F
+
2 3 4
+
VOUT = 2VIN C2 150F
LTC660 GND CAP -
* SCHOTTKY DIODE IS FOR START-UP ONLY
LTC660 * F08
Figure 8. Voltage Doubler
Ultraprecision Voltage Divider An ultraprecision voltage divider is shown in Figure 9. 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.
1 2 8 7 LTC660 6 5 V+ 3V TO 11V
+
C1 150F
3 4
V+ 0.002% 2 TMIN TA TMAX IL 100nA
+
C2 150F
LTC660 * F09
Figure 9. Ultraprecision Voltage Divider
Battery Splitter A common need in many systems is to obtain positive and negative 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 positive or negative output voltages, both equal to one-half the input voltage. The output voltages are both referenced to Pin 3 (Output Common).
LTC660
TYPICAL APPLICATIONS N
VB (9V) 1 2 8 7 LTC660 6 5 -VB/2 (-4.5V) C2 150F OUTPUT COMMON
LTC1046 * TA10
+
C1 150F
3 4
3V VB 11V
Figure 10. Battery Splitter
1 2
8 7 LTC660 6 5
+
C1 150F
3 4
OPTIONAL SYNCHRONIZATION CIRCUIT TO MINIMIZE RIPPLE
Figure 11. Paralleling for 200mA Load Current
V+
FOR VOUT = -3V +
1 2
8 7 LTC660 1 6 5 -V +
150F
1 2 3 4 LTC660 2
8 7 6 5 VOUT
+
150F
3 4
150F
150F
Figure 12. Stacking for High Voltage
+
+
+
+
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Paralleling for Lower Output Resistance
+VB/2 (4.5V)
Additional flexibility of the LTC660 is shown in Figures 11 and 12. Figure 11 shows two LTC660s 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. Stacking for Higher Voltage Figure 12 makes use of "stacking" two LTC660s 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 LTC660 is connected, as shown schematically by the switch.
V+ 1 2 8 7 LTC660 6 5 VOUT = -V + C2 150F
+
C1 150F
3 4
1/4 CD4077
LTC660 * F11
FOR VOUT = -2V +
LTC660 * F12
9
LTC660
PACKAGE DESCRIPTION U
Dimensions in inches (millimeters) unless otherwise noted.
N8 Package 8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.400* (10.160) MAX 8 7 6 5
0.255 0.015* (6.477 0.381)
1 0.300 - 0.325 (7.620 - 8.255)
2
3
4 0.130 0.005 (3.302 0.127)
0.045 - 0.065 (1.143 - 1.651)
0.009 - 0.015 (0.229 - 0.381)
0.065 (1.651) TYP 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 0.003 (0.457 0.076) N8 1197
(
+0.035 0.325 -0.015 8.255 +0.889 -0.381
)
0.100 0.010 (2.540 0.254)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
10
LTC660
PACKAGE DESCRIPTION
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0- 8 TYP
0.016 - 0.050 0.406 - 1.270
*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
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.
U
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) 8 7 6 5
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157** (3.810 - 3.988)
1 0.053 - 0.069 (1.346 - 1.752)
2
3
4
0.004 - 0.010 (0.101 - 0.254)
0.014 - 0.019 (0.355 - 0.483)
0.050 (1.270) TYP
SO8 0996
11
LTC660
TYPICAL APPLICATIONS N
Voltage Inverter
1 2 BOOST V+ 8 VIN 1.5V TO 5.5V
Voltage Doubler
1N5817*
1
BOOST CAP
+
V+ OSC LV VOUT
8 7 6 5
VIN 2.5V TO 5.5V
C1 150F
+
2 3 4
LTC660 GND CAP -
* SCHOTTKY DIODE IS FOR START-UP ONLY
RELATED PARTS
PART NUMBER Unregulated Output Voltage LTC660 LTC1046 LTC1044 LTC1044A LTC1144 Regulated Output Voltage LT1054 LTC1262 LTC1261 100mA 30mA 10mA 16V 6V 9V Adjustable Output 12V Fixed Output - 4V, - 4.5V and Adjustable Outputs 100mA 50mA 20mA 20mA 20mA 6V 6V 9.5V 13V 20V Highest Voltage Lowest Cost Highest Current OUTPUT CURRENT MAXIMUM VIN COMMENTS
All devices are available in plastic 8-lead SO and PDIP packages
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
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C1 150F
7 CAP+ OSC LTC660 6 3 GND LV 4 CAP - VOUT 5 VOUT = -VIN C2 150F
LTC660 * F07
+
VOUT = 2VIN C2 150F
LTC660 * F08
LT/GP 0598 2K REV A * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1995

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