Santa Clara, CA--May 27, 1997--National Semiconductor Corp. (Santa Clara, CA) introduced the LM2660 and LM2661 CMOS charge-pump voltage converters.
Both parts are housed in mini surface-mount SO-8 packages (MSOP) that are 50 percent smaller than competitive SO-8 packages. They're designed for use in a variety of handheld battery-operated equipment, as well as PCMCIA cards and hard disk drives. Unlike other types of switchers, switched capacitor circuits require no external inductor.
The LM2660 and LM2661 convert a range of supply voltages from 1.5V to 5.5V at a typical efficiency of greater than 90 percent, requiring 120 mA operating current for most loads. The low output impedence of just 6 ohms limits the voltage droop to 0.6V at 100mA. Both devices are ideal for a variety of portable applications demanding up to 100mA output current and low EMI. The LM2661 also includes a low-current shutdown mode. Shutdown current is typically less than 1 mA.
Specifically, switched capacitor converters are designed to invert a positive voltage to the corresponding negative voltage, or as an input voltage doubler at high efficiencies. Although two low-cost capacitors are required in switched capacitor circuits to provide the output current, the external inductor needed with inductor-based switchers is not.
The LM2660M and LM2661M (SO-8 package) are priced at $1.59 each in 1,000-piece quantities. The LM2660MM and LM2661MM (MSOP) are $1.68, also in 1,000s.
Santa Clara, CA
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