
T he ADM660 is a pin compatible upgrade for the MAX 660,
MAX 665, ICL7660 and LT C1046.
T he ADM660/ADM8660 is available in 8-pin DIP and narrow-
body SOIC. T he ADM660 is also available in a 16-lead T SSOP
package.
ADM660/ADM8660 Options
Option
ADM660
ADM8660
Inverting Mode
Doubling Mode
External Oscillator
Shutdown
Package Options
SO-8
N-8
RU-16
Y
Y
Y
N
Y
N
N
Y
Y
Y
Y
Y
Y
N
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
CMOS Swtched-Capacitor
Voltage Converters
ADM660/ADM8660
FEATURES
ADM660: Inverts or Doubles Input Supply Voltage
ADM8660: Inverts Input Supply Voltage
100 mA Output Current
Shutdown Function (ADM8660)
2.2
m
F or 10
m
F Capacitors
0.3 V Drop at 30 mA Load
+1.5 V to +7 V Supply
Low Power CMOS: 600
m
A Quiescent Current
Selectable Charge Pump Frequency (25 kHz/120 kHz)
Pin Compatible Upgrade for MAX660, MAX665, ICL7660
Available in 16-Lead TSSOP Package
APPLICATIONS
Handheld Instruments
Portable Computers
Remote Data Acquisition
Op Amp Power Supplies
T Y PICAL CIRCUIT CONFIGURAT IONS
INVERTED
NEGATIVE
OUTPUT
+1.5V TO +7V
INPUT
C1
10μF
C2
10μF
ADM660
V+
GND
OUT
LV
OSC
FC
CAP+
CAP–
Voltage Inverter Configuration (ADM660)
INVERTED
NEGATIVE
OUTPUT
+1.5V TO +7V
INPUT
C1
10μF
C2
10μF
ADM8660
V+
GND
OUT
LV
FC
CAP+
CAP–
SD
SHUTDOWN
CONTROL
Voltage Inverter Configuration with Shutdown (ADM8660)
GE NE RAL DE SCRIPT ION
T he ADM660/ADM8660 is a charge-pump voltage converter
that can be used to either invert the input supply voltage giving
V
OUT
= –V
IN
or double it (ADM660 only) giving V
OUT
= 2
×
V
IN
.
Input voltages ranging from +1.5 V to +7 V can be inverted into
a negative –1.5 V to –7 V output supply. T his inverting scheme
is ideal for generating a negative rail in single power supply
systems. Only two small external capacitors are needed for the
charge pump. Output currents up to 50 mA with greater than
90% efficiency are achievable, while 100 mA achieves greater
than 80% efficiency.
A Frequency Control (FC) input pin is used to select either
25 kHz or 120 kHz charge-pump operation. T his is used to
optimize capacitor size and quiescent current. With 25 kHz
selected, a 10
μ
F external capacitor is suitable, while with
120 kHz the capacitor may be reduced to 2.2
μ
F. T he oscillator
frequency on the ADM660 can also be controlled with an exter-
nal capacitor connected to the OSC input or by driving this in-
put with an external clock. In applications where a higher supply
voltage is desired it is possible to use the ADM660 to double
the input voltage. With input voltages from 2.5 V to 7 V, output
voltages from 5 V to 14 V are achievable with up to 100 mA
output current.
T he ADM8660 features a low power shutdown (SD) pin in-
stead of the external oscillator (OSC) pin. T his can be used to
disable the device and reduce the quiescent current to 300 nA.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
World Wide Web Site: http://www.analog.com
Fax: 617/326-8703
Analog Devices, Inc., 1997