3-36
File Number
3179.2
ICL7660S
Super Voltage Converter
The ICL7660S Super Voltage Converter is a monolithic
CMOS voltage conversion IC that guarantees significant
performance advantages over other similar devices. It is a
direct replacement for the industry standard ICL7660 offering
an extended operating supply voltage range up to 12V, with
lower supply current. No external diode is needed for the
ICL7660S. In addition, a Frequency Boost pin has been
incorporated to enable the user to achieve lower output
impedance despite using smaller capacitors. All
improvements are highlighted in the Electrical Specifications
section. Critical parameters are guaranteed over the entire
commercial, industrial and military temperature ranges.
The ICL7660S performs supply voltage conversion from
positive to negative for an input range of 1.5V to 12V,
resulting in complementary output voltages of -1.5V to -12V.
Only 2 non-critical external capacitors are needed for the
charge pump and charge reservoir functions. The ICL7660S
can be connected to function as a voltage doubler and will
generate up to 22.8V with a 12V input. It can also be used as
a voltage multiplier or voltage divider.
The chip contains a series DC power supply regulator, RC
oscillator, voltage level translator, and four output power
MOS switches. The oscillator, when unloaded, oscillates at a
nominal frequency of 10kHz for an input supply voltage of
5.0V. This frequency can be lowered by the addition of an
external capacitor to the "OSC" terminal, or the oscillator
may be over-driven by an external clock.
The "LV" terminal may be tied to GND to bypass the internal
series regulator and improve low voltage (LV) operation. At
medium to high voltages (3.5V to 12V), the LV pin is left
floating to prevent device latchup.
Features
Guaranteed Lower Max Supply Current for All
Temperature Ranges
Wide Operating Voltage Range 1.5V to 12V
100% Tested at 3V
No External Diode Over Full Temperature and Voltage
Range
Boost Pin (Pin 1) for Higher Switching Frequency
Guaranteed Minimum Power Efficiency of 96%
Improved Minimum Open Circuit Voltage Conversion
Efficiency of 99%
Improved SCR Latchup Protection
Simple Conversion of +5V Logic Supply to
5V Supplies
Simple Voltage Multiplication V
OUT
= (-)nV
IN
Easy to Use - Requires Only 2 External Non-Critical
Passive Components
Improved Direct Replacement for Industry Standard
ICL7660 and Other Second Source Devices
Applications
Simple Conversion of +5V to
5V Supplies
Voltage Multiplication V
OUT
=
nV
IN
Negative Supplies for Data Acquisition Systems and
Instrumentation
RS232 Power Supplies
Supply Splitter, V
OUT
=
V
S
/2
Pinouts
ICL7660S (PDIP, SOIC)
TOP VIEW
ICL7660S (CAN)
TOP VIEW
Ordering Information
PART
NUMBER
TEMP.
RANGE
(
o
C)
PACKAGE
PKG. NO.
ICL7660SCBA
0 to 70
8 Ld P SOIC (N)
M8.15
ICL7660SCPA
0 to 70
8 Ld PDIP
E8.3
ICL7660SIBA
-40 to 85
8 Ld P SOIC (N)
M8.15
ICL7660SIPA
-40 to 85
8 Ld PDIP
E8.3
ICL7660SMTV
(Note)
-55 to 125
8 Pin Metal Can
T8.C
NOTE: Add /883B to part number if 883B processing is required.
BOOST
CAP+
GND
CAP-
1
2
3
4
8
7
6
5
V+
OSC
LV
V
OUT
V+ (AND CASE)
LV
CAP+
CAP-
BOOST
GND
OSC
V
OUT
2
4
6
1
3
7
5
8
Data Sheet
April 1999
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207
|
Copyright
Intersil Corporation 1999
3-37
Absolute Maximum Ratings
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +13.0V
LV and OSC Input Voltage (Note 1)
V+ < 5.5V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to V+ + 0.3V
V+ > 5.5V . . . . . . . . . . . . . . . . . . . . . . . . . . . V+ -5.5V to V+ +0.3V
Current into LV (Note 1)
V+ > 3.5V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
A
Output Short Duration
V
SUPPLY
5.5V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
Storage Temperature Range . . . . . . . . . . . . . . . . . . -65
o
C to 150
o
C
Operating Conditions
Temperature Range
ICL7660SM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55
o
C to 125
o
C
ICL7660SI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to 85
o
C
ICL7660SC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0
o
C to 70
o
C
Thermal Resistance (Typical, Note 2)
JA
(
o
C/W)
JC
(
o
C/W)
PDIP. . . . . . . . . . . . . . . . . . . . . . . . . . .
150
N/A
Plastic SOIC. . . . . . . . . . . . . . . . . . . . .
170
N/A
Metal Can. . . . . . . . . . . . . . . . . . . . . . .
155
70
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300
o
C
(SOIC - Lead Tips Only)
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. Connecting any terminal to voltages greater than V+ or less than GND may cause destructive latchup. It is recommended that no inputs from
sources operating from external supplies be applied prior to "power up" of ICL7660S.
2.
JA
is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
V+ = 5V, T
A
= 25
o
C, OSC = Free running, Test Circuit Figure 12, Unless Otherwise Specified
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current (Note 5)
I+
R
L
=
, 25
o
C
-
80
160
A
0
o
C < T
A
< +70
o
C
-
-
180
A
-40
o
C < T
A
< 85
o
C
-
-
180
A
-55
o
C < T
A
< 125
o
C
-
-
200
A
Supply Voltage Range - High
(Note 6)
V+
H
R
L
= 10K, LV Open, T
MIN
< T
A
< T
MAX
3.0
-
12
V
Supply Voltage Range - Low
V+
L
R
L
= 10K, LV to GND, T
MIN
< T
A
< T
MAX
1.5
-
3.5
V
Output Source Resistance
R
OUT
I
OUT
= 20mA
-
60
100
I
OUT
= 20mA, 0
o
C < T
A
< 70
o
C
-
-
120
I
OUT
= 20mA, -25
o
C < T
A
< 85
o
C
-
-
120
I
OUT
= 20mA, -55
o
C < T
A
< 125
o
C
-
-
150
I
OUT
= 3mA, V+ = 2V, LV = GND,
0
o
C < T
A
< 70
o
C
-
-
250
I
OUT
= 3mA, V+ = 2V, LV = GND,
-40
o
C < T
A
< 85
o
C
-
-
300
I
OUT
= 3mA, V+ = 2V, LV = GND,
-55
o
C < T
A
< 125
o
C
-
-
400
Oscillator Frequency (Note 5)
f
OSC
C
OSC
= 0, Pin 1 Open or GND
5
10
-
kHz
C
OSC
= 0, Pin 1 = V+
-
35
-
kHz
Power Efficiency
P
EFF
R
L
= 5k
96
98
-
%
T
MIN
< T
A
< T
MAX
R
L
= 5k
95
97
-
-
Voltage Conversion Efficiency
V
OUT
EFF
R
L
=
99
99.9
-
%
ICL7660S
3-38
Oscillator Impedance
Z
OSC
V+ = 2V
-
1
-
M
V+ = 5V
-
100
-
k
NOTES:
3. Derate linearly above 50
o
C by 5.5mW/
o
C
4. In the test circuit, there is no external capacitor applied to pin 7. However, when the device is plugged into a test socket, there is usually a very
small but finite stray capacitance present, of the order of 5pF.
5. The Intersil ICL7660S can operate without an external diode over the full temperature and voltage range. This device will function in existing
designs which incorporate an external diode with no degradation in overall circuit performance.
6. All significant improvements over the industry standard ICL7660 are highlighted.
Electrical Specifications
V+ = 5V, T
A
= 25
o
C, OSC = Free running, Test Circuit Figure 12, Unless Otherwise Specified (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Typical Performance Curves
(Test Circuit Figure 12)
FIGURE 1. OPERATING VOLTAGE AS A
FUNCTION OF TEMPERATURE
FIGURE 2. OUTPUT SOURCE RESISTANCE AS A
FUNCTION OF SUPPLY VOLTAGE
FIGURE 3. OUTPUT SOURCE RESISTANCE AS A
FUNCTION OF TEMPERATURE
FIGURE 4. POWER CONVERSION EFFICIENCY AS A
FUNCTION OF OSCILLATOR FREQUENCY
-55
-25
0
25
50
100
125
12
10
8
6
4
2
0
SUPPL
Y V
O
L
T
A
GE (V)
TEMPERATURE (
o
C)
SUPPLY VOLTAGE RANGE
(NO DIODE REQUIRED)
250
200
150
100
50
0
0
2
4
6
8
10
12
SUPPLY VOLTAGE (V)
OUTPUT SOURCE RESIST
ANCE (
)
T
A
= 125
o
C
T
A
= 25
o
C
T
A
= -55
o
C
350
300
250
200
150
100
50
0
OUTPUT SOURCE RESIST
ANCE (
)
-50
-25
0
25
50
75
100
125
TEMPERATURE (
o
C)
I
OUT
= 20mA,
V+ = 12V
I
OUT
= 20mA,
V+ = 5V
I
OUT
= 20mA,
V+ = 5V
I
OUT
= 3mA,
V+ = 2V
98
96
94
92
90
88
86
84
82
80
PO
WER CONVERSION EFFICIENCY (%)
100
1k
10k
50k
OSC FREQUENCY F
OSC
(Hz)
V+ = 5V
T
A
= 25
o
C
I
OUT
= 1mA
ICL7660S
3-39
FIGURE 5. FREQUENCY OF OSCILLATION AS A FUNCTION
OF EXTERNAL OSCILLATOR CAPACITANCE
FIGURE 6. UNLOADED OSCILLATOR FREQUENCY AS A
FUNCTION OF TEMPERATURE
FIGURE 7. OUTPUT VOLTAGE AS A FUNCTION
OF OUTPUT CURRENT
FIGURE 8. SUPPLY CURRENT AND POWER CONVERSION
EFFICIENCY AS A FUNCTION OF LOAD
CURRENT
FIGURE 9. OUTPUT VOLTAGE AS A FUNCTION OF OUTPUT
CURRENT
FIGURE 10. SUPPLY CURRENT AND POWER CONVERSION
EFFICIENCY AS A FUNCTION OF LOAD CURRENT
Typical Performance Curves
(Test Circuit Figure 12) (Continued)
1
10
100
1k
OSCILLA
T
OR FREQ
UENCY f
OSC
(kHz)
10
9
8
7
6
5
4
3
2
1
0
C
OSC
(pF)
V+ = 5V
T
A
= 25
o
C
OSCILLA
T
OR FREQ
UENCY f
OSC
(kHz)
20
18
16
14
12
10
8
-55
-25
0
25
50
75
100
125
TEMPERATURE (
o
C)
V+ = 10V
V+ = 5V
OUTPUT V
O
L
T
A
GE (V)
1
0
-1
-2
-3
-4
-5
0
10
20
30
40
LOAD CURRENT (mA)
V+ = 5V
T
A
= 25
o
C
PO
WER CONVERSION EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
LOAD CURRENT (mA)
0
10
20
30
40
50
60
V+ = 5V
T
A
= 25
o
C
SUPPL
Y CURRENT (mA)
OUTPUT V
O
L
T
A
GE (V)
2
1
0
-1
-2
0
1
2
3
4
5
6
7
8
9
LOAD CURRENT (mA)
T
A
= 25
o
C
V+ = 2V
100
90
80
70
60
50
40
30
20
10
0
16
14
12
10
8
6
4
2
0
0
1.5
3
4.5
6
7.5
9
LOAD CURRENT (mA)
V+ = 2V
T
A
= 25
o
C
PO
WER CONVERSION
EFFICIENCY (%)
SUPPL
Y CURRENT (mA) (NO
TE 8)
ICL7660S
3-40
Detailed Description
The ICL7660S contains all the necessary circuitry to
complete a negative voltage converter, with the exception of
2 external capacitors which may be inexpensive 10
F
polarized electrolytic types. The mode of operation of the
device may be best understood by considering Figure 13,
which shows an idealized negative voltage converter.
Capacitor C
1
is charged to a voltage, V+, for the half cycle
when switches S
1
and S
3
are closed. (Note: Switches S
2
and S
4
are open during this half cycle.) During the second
half cycle of operation, switches S
2
and S
4
are closed, with
S
1
and S
3
open, thereby shifting capacitor C
1
to C
2
such
that the voltage on C
2
is exactly V+, assuming ideal switches
and no load on C
2
. The ICL7660S approaches this ideal
situation more closely than existing non-mechanical circuits.
In the ICL7660S, the 4 switches of Figure 13 are MOS power
switches; S
1
is a P-Channel devices and S
2
, S
3
and S
4
are
N-Channel devices. The main difficulty with this approach is
that in integrating the switches, the substrates of S
3
and S
4
must always remain reverse biased with respect to their
sources, but not so much as to degrade their "ON"
resistances. In addition, at circuit start up, and under output
short circuit conditions (V
OUT
= V+), the output voltage must
be sensed and the substrate bias adjusted accordingly.
Failure to accomplish this would result in high power losses
and probable device latchup.
This problem is eliminated in the ICL7660S by a logic network
which senses the output voltage (V
OUT
) together with the
level translators, and switches the substrates of S
3
and S
4
to
the correct level to maintain necessary reverse bias.
The voltage regulator portion of the ICL7660S is an integral
part of the anti-latchup circuitry, however its inherent voltage
drop can degrade operation at low voltages. Therefore, to
improve low voltage operation "LV" pin should be connected
to GND, disabling the regulator. For supply voltages greater
than 3.5V the LV terminal must be left open to insure latchup
proof operation, and prevent device damage.
Theoretical Power Efficiency
Considerations
In theory a voltage converter can approach 100% efficiency
if certain conditions are met:
1. The drive circuitry consumes minimal power.
2. The output switches have extremely low ON resistance
and virtually no offset.
3. The impedance of the pump and reservoir capacitors are
negligible at the pump frequency.
FIGURE 11. OUTPUT SOURCE RESISTANCE AS A FUNCTION OF OSCILLATOR FREQUENCY
NOTE:
7. These curves include in the supply current that current fed directly into the load R
L
from the V+ (See Figure 12). Thus, approximately half the
supply current goes directly to the positive side of the load, and the other half, through the ICL7660S, to the negative side of the load. Ideally,
V
OUT
2V
IN
, I
S
2I
L
, so V
IN
x I
S
V
OUT
x I
L
.
Typical Performance Curves
(Test Circuit Figure 12) (Continued)
OUTPUT RESIST
ANCE (
)
400
300
200
100
0
100
1k
10k
100k
OSCILLATOR FREQUENCY (Hz)
V+ = 5V
T
A
= 25
o
C
I = 10mA
C
1
= C
2
=
10
F
C
1
= C
2
=
1
F
C
1
= C
2
=
100
F
1
2
3
4
8
7
6
5
+
-
C
1
10
F
I
S
V+
(+5V)
I
L
R
L
-
V
OUT
C
2
10
F
ICL7660S
V+
+
-
NOTE: For large values of C
OSC
(>1000pF) the values of C
1
and C
2
should be increased to 100
F.
FIGURE 12. ICL7660S TEST CIRCUIT
ICL7660S
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