1 Features

1• Inverts or Doubles Input Supply Voltage

• Narrow SOIC and VSSOP Packages

• 6.5-Ω Typical Output Resistance

• 88% Typical Conversion Efficiency at 100 mA

• Selectable Oscillator Frequency: 10 kHz/80 kHz

• Optional External Oscillator Input

2 Applications

• Laptop Computers

• Cellular Phones

• Medical Instruments

• Operational Amplifier Power Supplies

• Interface Power Supplies

• Handheld Instruments

3 Description

The LM2660 CMOS charge-pump voltage converter

is a versatile unregulated switched capacitor inverter or doubler. Operating from a wide 1.5-V to 5.5-V

supply voltage, the LM2660 uses two low-cost

capacitors to provide 100 mA of output current

without the cost, size and EMI related to inductor- based converters. With an operating current of only

120 μA and operating efficiency greater than 90% at

most loads, the LM2660 provides ideal performance

for battery-powered systems. LM2660 devices can be

operated directly in parallel to lower output

impedance, thus providing more current at a given

voltage.

The FC (frequency control) pin selects between a

nominal 10-kHz or 80-kHz oscillator frequency. The

oscillator frequency can be lowered by adding an

external capacitor to the OSC pin. Also, the OSC pin

may be used to drive the LM2660 with an external clock up to 150 kHz. Through these methods, output

ripple frequency and harmonics may be controlled.

Additionally, the LM2660 may be configured to divide

a positive input voltage precisely in half. In this mode,

input voltages as high as 11 V may be used.