CMOS Monolithic Voltage Converter

________________________________________________________________

Maxim Integrated Products

1

19-3293; Rev. 2; 9/96

_______________General Description

The MAX660 monolithic, charge-pump voltage inverter

converts a +1.5V to +5.5V input to a corresponding

-1.5V to -5.5V output. Using only two low-cost

capacitors, the charge pump’s 100mA output replaces

switching regulators, eliminating inductors and their

associated cost, size, and EMI. Greater than 90%

efficiency over most of its load-current range combined

with a typical operating current of only 120µA provides

ideal performance for both battery-powered and board-

level voltage conversion applications. The MAX660 can

also double the output voltage of an input power supply

or battery, providing +9.35V at 100mA from a +5V

input.

A frequency control (FC) pin selects either 10kHz typ or

80kHz typ (40kHz min) operation to optimize capacitor

size and quiescent current. The oscillator frequency

can also be adjusted with an external capacitor or

driven with an external clock. The MAX660 is a pin-

compatible, high-current upgrade of the ICL7660.

The MAX660 is available in both 8-pin DIP and small-

outline packages in commercial, extended, and military

temperature ranges.

For 50mA applications, consider the MAX860/MAX861

pin-compatible devices (also available in ultra-small

µMAX packages).

________________________Applications

Laptop Computers

Medical Instruments

Interface Power Supplies

Hand-Held Instruments

Operational-Amplifier Power Supplies

___________________________ Features

® Small Capacitors

® 0.65V Typ Loss at 100mA Load

® Low 120µA Operating Current

® 6.5Ω Typ Output Impedance

® Pin-Compatible High-Current ICL7660 Upgrade

® Inverts or Doubles Input Supply Voltage

® Selectable Oscillator Frequency: 10kHz/80kHz

® 88% Typ Conversion Efficiency at 100mA

1

2

3

2

1

3

4

7

8

5

6

8

7

6

5

MAX660

MAX660

FC

CAP+

GND

CAP-

V+

OSC

LV

OUT

FC

CAP+

GND

CAP-

V+

OSC

LV

OUT

C2

1

µF to 150µF

VOLTAGE INVERTER

POSITIVE VOLTAGE DOUBLER

1.5V TO 5.5V

INVERTED

NEGATIVE

VOLTAGE

OUTPUT

C1

1

µF to 150µF

DOUBLED

POSITIVE

VOLTAGE

OUTPUT

C2

1

µF to 150µF

C1

1

µF to 150µF

2.5V TO 5.5V

4

_________Typical Operating Circuits

1

2

3

4

8

7

6

5

V+

OSC

LV

OUT

CAP-

GND

CAP+

FC

MAX660

DIP/SO

TOP VIEW

__________________Pin Configuration

______________Ordering Information

PART

TEMP. RANGE

PIN-PACKAGE

MAX660CPA

0°C to +70°C

8 Plastic DIP

MAX660CSA

0°C to +70°C

8 SO

MAX660C/D

0°C to +70°C

Dice*

MAX660EPA

-40°C to +85°C

8 Plastic DIP

MAX660ESA

-40°C to +85°C

8 SO

*Contact factory for dice specifications.

MAX660MJA

-55°C to +125°C

8 CERDIP

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800