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.