LM2682

Switched Capacitor Voltage Doubling Inverter

General Description

The LM2682 is a CMOS charge-pump voltage inverter ca-

pable of converting positive voltage in the range of +2.0V to

+5.5V to the corresponding doubled negative voltage of

−4.0V to −11.0V respectively. The LM2682 uses three low

cost capacitors to provide 10 mA of output current without

the cost, size, and EMI related to inductor based circuits.

With an operating current of only 150 µA and an operating ef-

ficiency greater than 90% with most loads, the LM2682 pro-

vides ideal performance for battery powered systems. The

LM2682 offers a switching frequency of 6 kHz.

Features

n Inverts then doubles input supply voltage

n Small MSOP-8 package (mini SO-8) and SO-8 package

n 90

Ω typical output impedance

n 94% typical power efficiency at 10 mA

Applications

n LCD contrast biasing

n GaAs power amplifier biasing

n Interface power supplies

n Handheld instrumentation

n Laptop computers and PDAs

Typical Operating Circuit and Pin Configuration

Ordering Information

Order Number

Package

Package Number

Package Marking

Supplied As

LM2682MM

MSOP-8

MUA08A

S11A

Tape and Reel (1000 units/reel)

LM2682MMX

MSOP-8

MUA08A

S11A

Tape and Reel (3500 units/reel)

LM2682M

SO-8

M08A

LM2682M

Rail (95 units/rail)

LM2682MX

SO-8

M08A

LM2682M

Tape and Reel (2500 units/reel)

DS100997-1

8-Pin MSOP

or 8-Pin SOIC

DS100997-2

November 1999

© 1999 National Semiconductor Corporation

DS100997

www.national.com