LM2664

Switched Capacitor Voltage Converter

General Description

The LM2664 CMOS charge-pump voltage converter inverts

a positive voltage in the range of +1.8V to +5.5V to the cor-

responding negative voltage of −1.8V to −5.5V. The LM2664

uses two low cost capacitors to provide up to 40 mA of out-

put current.

The LM2664 operates at 160 kHz oscillator frequency to re-

duce output resistance and voltage ripple. With an operating

current of only 220 µA (operating efficiency greater than 91%

with most loads) and 1 µA typical shutdown current, the

LM2664 provides ideal performance for battery powered

systems. The device is in SOT-23-6 package.

Features

n Inverts Input Supply Voltage

n SOT23-6 Package

n 12

Ω Typical Output Impedance

n 91% Typical Conversion Efficiency at 40 mA

n 1µA Typical Shutdown Current

Applications

n Cellular Phones

n Pagers

n PDAs

n Operational Amplifier Power Suppliers

n Interface Power Suppliers

n Handheld Instruments

Basic Application Circuits

Voltage Inverter

DS100031-1

+5V to −10V Converter

DS100031-25

November 1999

© 1999 National Semiconductor Corporation

DS100031

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