1 Features

• Inverts or Doubles Input Supply Voltage
• Narrow SO-8 Package
• 6.5-Ω Typical Output Resistance
• 88% Typical Conversion Efficiency at 100 mA
• Selectable Oscillator Frequency: 10 kHz/80 kHz

2 Applications

• Laptop Computers
• Cellular Phones
• Medical Instruments
• Operational Amplifier Power Supplies
• Interface Power Supplies
• Handheld Instruments

3 Description

The MAX660 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 MAX660 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 MAX660 provides ideal performance for battery-powered systems. MAX660 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 MAX660 with an external clock up to 150 kHz. Through these methods, output ripple frequency and harmonics may be controlled.

Additionally, the MAX660 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.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Voltage Inverter

Positive Voltage Doubler