© Semiconductor Components Industries, LLC, 2012
July, 2012 − Rev. 26
1Publication Order Number:
CAT660/D
CAT660
100 mA CMOS Charge Pump
Inverter/Doubler
Description
The CAT660 is a charge−pump voltage converter. It will invert a
1.5 V to 5.5 V input to a −1.5 V to −5.5 V output. Only two external
capacitors are needed. With a guaranteed 100 mA output current
capability, the CAT660 can replace a switching regulator and its
inductor. Lower EMI is achieved due to the absence of an inductor.
In addition, the CAT660 can double a voltage supplied from a
battery or power supply. Inputs from 2.5 V to 5.5 V will yield a
doubled, 5 V to 11 V output voltage.
A Frequency Control pin (BOOST/FC) is provided to select either a
high (80 kHz) or low (10 kHz) internal oscillator frequency, thus
allowing quiescent current vs. capacitor size trade−offs to be made.
The 80 kHz frequency is selected when the FC pin is connected to V+.
The operating frequency can also be adjusted with an external
capacitor at the OSC pin or by driving OSC with an external clock.
8−pin SOIC package is available in the industrial temperature range.
The CAT660 replaces the MAX660 and the LTC®660. In addition,
the CAT660 is pin compatible with the 7660/1044, offering an easy
upgrade for applications with 100 mA loads.
Features
•Replaces MAX660 and LTC®660
•Converts V+ to V− or V+ to 2V+
•Low Output Resistance, 4 W Typical
•High Power Efficiency
•Selectable Charge Pump Frequency
− 10 kHz or 80 kHz
− Optimize Capacitor Size
•Low Quiescent Current
•Pin−compatible, High−current Alternative to 7660/1044
•Industrial Temperature Range
•Available in 8−pin SOIC Package
•These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
•Negative Voltage Generator
•Voltage Doubler
•Voltage Splitter
•Low EMI Power Source
•GaAs FET Biasing
•Lithium Battery Power Supply
•Instrumentation
•LCD Contrast Bias
•Cellular Phones, Pagers
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PIN CONFIGURATION
SOIC−8
V SUFFIX
CASE 751BD
(Top View)
V+
OSC
LV
OUT
BOOST/FC
CAP+
GND
CAP−
Device Package Shipping
ORDERING INFORMATION
MARKING DIAGRAMS
CAT660EVA−GT3 SOIC−8
(Pb−Free)
3,000 /
Tape & Reel
CAT660EVA
CAT660EVA = CAT660EVA−GT3
1
1. All packages are RoHS−compliant (Lead−free,
Halogen−free).
2. For information on tape and reel specifications, in-
cluding part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifica-
tions Brochure, BRD8011/D.
3. For detailed information and a breakdown of
device nomenclature and numbering systems,
please see the ON Semiconductor Device No-
menclature document, TND310/D, available at
www.onsemi.com
CAT660
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2
Typical Application
Figure 1. Voltage Inverter
V+
OSC
LV
OUT
CAT660
+
+
V+
OSC
LV
OUT
C1 C1 CAT660
1 mF to
150 mF
CAP+
GND
CAP−
BOOST/FC
1
2
3
4
8
7
6
5
C2 1 mF to
150 mF
+VIN
1.5 V to 5.5 V
Inverted
Negative
Voltage
Output
8
7
6
5
CAP+
GND
CAP−
BOOST/FC
1
2
3
4
1 mF to
150 mF
VIN = 2.5 V
to 5.5 V
1 mF to
150 mF
C2
Doubled
Positive
Voltage
Output
Figure 2. Positive Voltage Doubler
Table 1. PIN DESCRIPTIONS
Circuit Configuration
Pin Number Name Inverter Mode Doubler Mode
1 Boost/FC Frequency Control for the internal oscillator. With an external
oscillator BOOST/FC has no effect.
Same as inverter.
Boost/FC Oscillator Frequency
Open 10 kHz typical, 5 kHz minimum
V+ 80 kHz typical, 40 kHz minimum
2 CAP+ Charge pump capacitor. Positive terminal. Same as inverter.
3 GND Power supply ground. Power supply. Positive voltage input.
4 CAP−Charge pump capacitor. Negative terminal. Same as inverter.
5 OUT Output for negative voltage. Power supply ground.
6LV Low−Voltage selection pin. When the input voltage is less
than 3 V, connect LV to GND. For input voltages above 3 V,
LV may be connected to GND or left open. If OSC is driven
externally, connect LV to GND.
LV must be tied to OUT for all input
voltages.
7 OSC Oscillator control input. An external capacitor can be connec-
ted to lower the oscillator frequency. An external oscillator
can drive OSC and set the chip operating frequency. The
charge−pump frequency is one−half the frequency at OSC.
Same as inverter. Do not overdrive OSC
in doubling mode. Standard logic levels
will not be suitable. See the applications
section for additional information.
8 V+ Power supply. Positive voltage input. Positive voltage output.
CAT660
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3
Table 2. ABSOLUTE MAXIMUM RATINGS
Parameters Ratings Units
V+ to GND 6 V
Input Voltage (Pins 1, 6 and 7) −0.3 to (V+ + 0.3) V
BOOST/FC and OSC Input Voltage The least negative of (Out − 0.3 V) or
(V+ − 6 V) to (V+ + 0.3 V)
V
Output Short−circuit Duration to GND
(OUT may be shorted to GND for 1 sec without damage but shorting OUT
to V+ should be avoided.)
1 sec.
Continuous Power Dissipation (TA = 70°C)
Plastic DIP
SOIC
TDFN
730
500
1
mW
mW
W
Storage Temperature −65 to +160 °C
Lead Soldering Temperature (10 sec) 300 °C
Operating Ambient Temperature Range −40 to +85 °C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
NOTE: TA = Ambient Temperature
Table 3. ELECTRICAL CHARACTERISTICS (V+ = 5 V, C1 = C2 = 150 mF, Boost/FC = Open, COSC = 0 pF, inverter mode with test
circuit as shown in Figure 3 unless otherwise noted. Temperature is over operating ambient temperature range unless otherwise noted.)
Parameter Symbol Conditions Min Typ Max Units
Supply Voltage VS Inverter: LV = Open, RL = 1 kW3.0 5.5 V
Inverter: LV = GND, RL = 1 kW1.5 5.5
Doubler: LV = OUT, RL = 1 kW2.5 5.5
Supply Current IS BOOST/FC = open, LV = Open 0.09 0.5 mA
BOOST/FC = V+, LV = Open 0.3 3
Output Current IOUT OUT is more negative than −4 V 100 mA
Output Resistance RO IL = 100 mA, C1 = C2 = 150 mF (Note 5)
BOOST/FC = V+ (C1, C2 ESR ≤ 0.5 W)
4 7 W
IL = 100 mA, C1 = C2 = 10 mF12
Oscillator Frequency
(Note 6)
FOSC BOOST/FC = Open 5 10 kHz
BOOST/FC = V+ 40 80
OSC Input
Current
IOSC BOOST/FC = Open
BOOST/FC = V+
±1
±5
mA
Power Efficiency PE RL = 1 kW connected between V+ and OUT,
TA = 25°C (Doubler)
96 98 %
RL = 500 W connected between GND and OUT,
TA = 25°C (Inverter)
92 96
IL = 100 mA to GND, TA = 25°C (Inverter) 88
Voltage Conversion
Efficiency
VEFF No load, TA = 25°C 99 99.9 %
4. In Figure 3, test circuit capacitors C1 and C2 are 150 mF and have 0.2 W maximum ESR. Higher ESR levels may reduce efficiency and output
voltage.
5. The output resistance is a combination of the internal switch resistance and the external capacitor ESR. For maximum voltage and efficiency
keep external capacitor ESR under 0.2 W.
6. FOSC is tested with COSC = 100 pF to minimize test fixture loading. The test is correlated back to COSC = 0 pF to simulate the capacitance
at OSC when the device is inserted into a test socket without an external COSC.
CAT660
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4
Voltage Inverter
Figure 3. Test Circuit
CAT660
External
Oscillator
C2
150 mF
+
BOOST/FC V+
OSC
LV
OUT
C1
150 mF
V+1
2
3
4
CAP+
CAP−
GND
8
7
6
5
ISV+
5 V
COSC
RL
IL
VOUT
+
TYPICAL OPERATING CHARACTERISTICS
(Typical characteristic curves are generated using the test circuit in Figure 3. Inverter test conditions are: V+ = 5 V, LV = GND, BOOST/FC
= Open and TA = 25°C unless otherwise indicated. Note that the charge−pump frequency is one−half the oscillator frequency.)
Figure 4. Supply Current vs. Input Voltage Figure 5. Supply Current vs. Temperature
(No Load)
INPUT VOLTAGE (V) TEMPERATURE (°C)
654321
0
30
60
90
120
150
1251007550250−25−50
0
20
40
60
80
100
120
Figure 6. Output Resistance vs. Input Voltage Figure 7. Output Resistance vs. Temperature
(50 W Load)
INPUT VOLTAGE (V) TEMPERATURE (°C)
654321
0
2
4
6
8
10
1251007550250−25−50
2
3
4
5
6
7
8
INPUT CURRENT (mA)
INPUT CURRENT (mA)
OUTPUT RESISTANCE (W)
OUTPUT RESISTANCE (W)
No Load
VIN = 5 V
VIN = 3 V
VIN = 2 V
100 W Load
VIN = 2 V
VIN = 3 V
VIN = 5 V
CAT660
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5
TYPICAL OPERATING CHARACTERISTICS
Figure 8. Inverted Output Voltage vs. Load,
V+ = 5 V
Figure 9. Output Voltage Drop vs. Load
Current
LOAD CURRENT (mA) LOAD CURRENT (mA)
100806040200
4.0
4.2
4.4
4.6
4.8
5.0
100806040200
0
0.2
0.4
0.6
0.8
1.0
Figure 10. Oscillator Frequency vs. Supply
Voltage
Figure 11. Oscillator Frequency vs. Supply
Voltage
SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V)
65432
0
2
6
8
12
14
18
20
65432
0
50
100
150
200
Figure 12. Supply Current vs. Oscillator
Frequency
OSCILLATOR FREQUENCY (kHz)
1,000100101
10
100
1,000
10,000
INV. OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
FREQUENCY (kHz)
FREQUENCY (kHz)
INPUT CURRENT (mA)
4
10
16
BOOST = OPEN
LV = OPEN
LV = GND
V+ = 5 V
V+ = 3 V
BOOST = +V
LV = OPEN
LV = GND
No Load
V+ = 5 V
CAT660
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6
Application Information
Circuit Description and Operating Theory
The CAT660 switches capacitors to invert or double an
input voltage.
Figure 13 shows a simple switch capacitor circuit. In
position 1 capacitor C1 is charged to voltage V1. The total
charge on C1 is Q1 = C1V1. When the switch moves to
position 2, the input capacitor C1 is discharged to voltage
V2. After discharge, the charge on C1 is Q2 = C1V2.
The charge transferred is:
DQ+Q1 *Q2 +C1 (V1 *V2)
If the switch is cycled “F” times per second, the current
(charge transfer per unit time) is:
I+F DQ+F C1 (V1 *V2)
Rearranging in terms of impedance:
I+(V1 *V2)
(1ńFC1) +V1 *V2
REQ
The 1/FC1 term can be modeled as an equivalent
impedance REQ. A simple equivalent circuit is shown in
Figure 14. This circuit does not include the switch resistance
nor does it include output voltage ripple. It does allow one
to understand the switch−capacitor topology and make
prudent engineering tradeoffs.
For example, power conversion efficiency is set by the
output impedance, which consists of REQ and switch
resistance. As switching frequency is decreased, REQ, the
1/FC1 term, will dominate the output impedance, causing
higher voltage losses and decreased efficiency. As the
frequency is increased quiescent current increases. At high
frequency this current becomes significant and the power
efficiency degrades.
The oscillator is designed to operate where voltage losses
are a minimum. With external 150 mF capacitors, the internal
switch resistances and the Equivalent Series Resistance
(ESR) of the external capacitors determine the effective
output impedance.
A block diagram of the CAT660 is shown in Figure 15.
The CAT660 is a replacement for the MAX660 and the
LTC660.
Figure 13. Switched−Capacitor Building Block Figure 14. Switched−Capacitor Equivalent Circuit
V1
C1
V2 V1 V2
REQ
C2
RLRL
C2
REQ +1
FC1
CAT660
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Oscillator Frequency Control
The switching frequency can be raised, lowered or driven
from an external source. Figure 16 shows a functional
diagram of the oscillator circuit.
The CAT660 oscillator has four control modes:
Table 4.
BOOST/FC
Pin Connection
OSC Pin
Connection
Nominal
Oscillator
Frequency
Open Open 10 kHz
BOOST/FC = V+ Open 80 kHz
Open or
BOOST/FC = V+
External Capacitor −
Open External Clock Frequency of
external clock
If BOOST/FC and OSC are left floating (Open), the
nominal oscillator frequency is 10 kHz. The pump
frequency is one−half the oscillator frequency.
By connecting the BOOST/FC pin to V+, the charge and
discharge currents are increased, and the frequency is
increased by approximately 8 times. Increasing the
frequency will decrease the output impedance and ripple
currents. This can be an advantage at high load currents.
Increasing the frequency raises quiescent current but allows
smaller capacitance values for C1 and C2.
If pin 7, OSC, is loaded with an external capacitor the
frequency is lowered. By using the BOOST/FC pin and an
external capacitor at OSC, the operating frequency can be
set.
Note that the frequency appearing at CAP+ or CAP− is
one−half that of the oscillator.
Driving the CAT660 from an external frequency source
can be easily achieved by driving Pin 7 and leaving the
BOOST pin open, as shown in Figure 16. The output current
from Pin 7 is small, typically 1 mA to 8 mA, so a CMOS can
drive the OSC pin. For 5 V applications, a TTL logic gate can
be used if an external 100 kΩ pull−up resistor is used as
shown in Figure 17.
Figure 15. CAT660 Block Diagram
+
C2
OSC
BOOST/FC
OSC
(7)
GND
(3)
C1
+
(2)
SW2
SW1
VOUT
(5)
(N) = Pin Number
LV
(6)
8x
(1)
f
f
B2
V+
(8)
CLOSED WHEN
V+ > 3.0 V
CAP+
(4)
CAP−
CAT660
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Capacitor Selection
Low ESR capacitors are necessary to minimize voltage
losses, especially at high load currents. The exact values of
C1 and C2 are not critical but low ESR capacitors are
necessary.
The ESR of capacitor C1, the pump capacitor, can have a
pronounced effect on the output. C1 currents are
approximately twice the output current and losses occur on
both the charge and discharge cycle. The ESR effects are
thus multiplied by four. A 0.5 Ω ESR for C1 will have the
same effect as a 2 Ω increase in CAT660 output impedance.
Output voltage ripple is determined by the value of C2 and
the load current. C2 is charged and discharged at a current
roughly equal to the load current. The internal switching
frequency is one−half the oscillator frequency.
VRIPPLE +IOUTń(FOSC C2) )IOUT ESRC2
For example, with a 10 kHz oscillator frequency (5 kHz
switching frequency), a 150 mF C2 capacitor with an ESR of
0.2 Ω and a 100 mA load peak−to−peak ripple voltage is
87 mV.
Table 5. VRIPPLE vs. FOSC
VRIPPLE (mV) IOUT (mA) FOSC (kHz) C2 (mF) C2 ESR (W)
87 100 10 150 0.2
28 100 80 150 0.2
Figure 16. Oscillator Figure 17. External Clocking
+C2
REQUIRED FOR TTL LOGIC
CAT660
100 k OSC
NC
+
C1
BOOST/FC V+
OSC
LV
OUT
BOOST/FC
(1)
OSC
(7)
~18 pF
I
7.0 I
I
7.0 I
V+
LV
(6)
INPUT
V+
−V+
CAP+
GND
CAP−
1
2
3
4
8
7
6
5
CAT660
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Capacitor Suppliers
The following manufacturers supply low−ESR capacitors:
Table 6. CAPACITOR SUPPLIERS
Manufacturer Capacitor Type Phone WEB Email Comments
AVX/Kyocera TPS/TPS3 843−448−9411 www.avxcorp.com avx@avxcorp.com Tantalum
Vishay/Sprague 595 402−563−6866 www.vishay.com −Aluminum
Sanyo MV−AX, UGX 619−661−6835 www.sanyo.com Svcsales@sanyo.com Aluminum
Nichicon F55 847−843−7500 www.nichicon−us.com −Tantalum
HC/HD Aluminum
Capacitor manufacturers continually introduce new series and offer different package styles. It is recommended that before
a design is finalized capacitor manufacturers should be surveyed for their latest product offerings.
Controlling Loss in CAT660 Applications
There are three primary sources of voltage loss:
1. Output resistance:
VLOSSW = ILOAD x ROUT, where ROUT is the
CAT660 output resistance and ILOAD is the load
current.
2. Charge pump (C1) capacitor ESR:
VLOSSC1 ≈ 4 x ESRC1 x ILOAD, where
ESRC1 is the ESR of capacitor C1.
3. Output or reservoir (C2) capacitor ESR:
VLOSSC2 = ESRC2 x ILOAD, where ESRC2 is
the ESR of capacitor C2.
Increasing the value of C2 and/or decreasing its ESR will
reduce noise and ripple.
The effective output impedance of a CAT660 circuit is
approximately:
Rcircuit [Rout 660 )(4 ESRC1) )ESRC2
CAT660
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Typical Applications
Voltage Inversion Positive−to−Negative
The CAT660 easily provides a negative supply voltage from a positive supply in the system. Figure 18 shows a typical circuit.
The LV pin may be left floating for positive input voltages at or above 3.3 V.
Figure 18. Voltage Inverter
+
C2
CAT660
NC
+
C1
BOOST/FC V+
OSC
LV
OUT
1
2
3
4
8
7
6
5
CAP+
CAP−
GND
VIN
1.5 V to 5.5 V
VOUT = −VIN
Positive Voltage Doubler
The voltage doubler circuit shown in Figure 19 gives VOUT = 2 x VIN for input voltages from 2.5 V to 5.5 V.
Figure 19. Voltage Doubler
CAT660
+
BOOST/FC +
2.5 V to 5.5 V
1N5817*
*SCHOTTKY DIODE IS FOR START−UP ONLY
V+
OSC
LV
OUT
C2
150 mF
VOUT = 2VIN
8
7
6
5
1
2
3
4
C1
150 mF
CAP+
CAP−
GND
VIN
CAT660
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Precision Voltage Divider
A precision voltage divider is shown in Figure 20. With very light load currents under 100 nA, the voltage at pin 2 will be
within 0.002% of V+/2. Output voltage accuracy decreases with increasing load.
Figure 20. Precision Voltage Divider (Load 3 100 nA)
+
+
BOOST/FC V+
OSC
LV
OUT
CAT660
C2
150 mF
C1
150 mF
1
2
3
4
CAP+
CAP−
GND
8
7
6
5
3 V to 11 V
V+
IL ≤ 100 nA
± 0.002%
V)
2
Battery Voltage Splitter
Positive and negative voltages that track each other can be obtained from a battery. Figure 21 shows how a 9 V battery can
provide symmetrical positive and negative voltages equal to one−half the battery voltage.
Figure 21. Battery Splitter
+
CAT660
+
BOOST/FC V+
OSC
LV
OUT
9 V
BATTERY
VBAT
C1
150 mF
3 V ≤ VBAT ≤ 11 V
1
CAP+
CAP−
GND
2
3
4
8
7
6
5
C2
150 mF
*VBAT
2(−4.5 V)
)VBAT
2(4.5 V)
CAT660
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Cascade Operation for Higher Negative Voltages
The CAT660 can be cascaded as shown in Figure 22 to generate more negative voltage levels. The output resistance is
approximately the sum of the individual CAT660 output resistance.
VOUT = −N x VIN, where N represents the number of cascaded devices.
Figure 22. Cascading to Increase Output Voltage
+
C2
4
8
5
+
C1
+CAT660
4
8
5
C1
+
C2
VOUT = −NVIN
3
2
“N”
CAT660
“1”
3
2
+VIN
Parallel Operation
Paralleling CAT660 devices will lower output resistance. As shown in Figure 23, each device requires its own pump
capacitor, C2, but the output reservoir capacitor is shared with all devices. The value of C2 should be increased by a factor of
N, where N is the number of devices.
The output impedance of the combined CAT660’s is:
ROUT (Of “N” CAT660Ȁs) +ROUT (Of the CAT660)
N (Number of devices)
Figure 23. Paralleling Devices Reduce Output Resistance
+
C2
4
8
5
+
C1
+
4
8
5
C1
CAT660
3
2
“N”
CAT660
“1”
3
2
+VIN
CAT660
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PACKAGE DIMENSIONS
SOIC 8, 150 mils
CASE 751BD−01
ISSUE O
E1 E
A
A1
h
θ
L
c
eb
D
PIN # 1
IDENTIFICATION
TOP VIEW
SIDE VIEW END VIEW
Notes:
(1) All dimensions are in millimeters. Angles in degrees.
(2) Complies with JEDEC MS-012.
SYMBOL MIN NOM MAX
θ
A
A1
b
c
D
E
E1
e
h
0º 8º
0.10
0.33
0.19
0.25
4.80
5.80
3.80
1.27 BSC
1.75
0.25
0.51
0.25
0.50
5.00
6.20
4.00
L0.40 1.27
1.35
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CAT660/D
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