The ADM660 is a pin compatible upgrade for the MAX660,

MAX665, ICL7660 and LTC1046.

The ADM660/ADM8660 is available in 8-pin DIP and narrow-

body SOIC. The ADM660 is also available in a 16-lead TSSOP

package.

ADM660/ADM8660 Options

Option

ADM660

ADM8660

Inverting Mode

Y

Y

Doubling Mode

Y

N

External Oscillator

Y

N

Shutdown

N

Y

Package Options

SO-8

Y

Y

N-8

Y

Y

RU-16

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 Switched-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

F or 10

F Capacitors

0.3 V Drop at 30 mA Load

+1.5 V to +7 V Supply

Low Power CMOS: 600

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

TYPICAL CIRCUIT CONFIGURATIONS

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)

GENERAL DESCRIPTION

The ADM660/ADM8660 is a charge-pump voltage converter

that can be used to either invert the input supply voltage giving

× V

Input voltages ranging from +1.5 V to +7 V can be inverted into

a negative –1.5 V to –7 V output supply. This 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. This is used to

optimize capacitor size and quiescent current. With 25 kHz

selected, a 10

µF external capacitor is suitable, while with

120 kHz the capacitor may be reduced to 2.2

µF. The 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.

The ADM8660 features a low power shutdown (SD) pin in-

stead of the external oscillator (OSC) pin. This 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