National Semiconductor Re-enters Switched Capacitor Voltage Converter Market With New Offerings in Mini SO-8 (MSOP) Surface-Mount Packages

May 27, 1997 -- National Semiconductor Corporation® today re-positioned itself in the forefront of the switched capacitor market with the introduction of the LM2660 and LM2661 CMOS charge-pump voltage converters. Both parts are housed in mini surface-mount SO-8 packages (MSOP) that are 50% smaller than competitive SO-8 packages. They are 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 size and performance advantage of these devices reaffirms National 's commitment to supply leading-edge voltage converters for today's new portable computing and communications products, " noted Venkatesh Shan, National's power management marketing manager. "Although the switched capacitor architecture is not new, National's latest fab technologies have allowed spectacular product performance improvement, opening up many new designs to switch capacitors."

The LM2660 and LM2661 convert a range of supply voltages from 1.5V to 5.5V at a typical efficiency of 90%, requiring only 120 microamp 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 1microamp. 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.

Price and Availability
The LM2660M and LM2661M (SO-8 package) are priced at $1.59 each in 1000-piece quantities. The LM2660MM and LM2661MM (MSOP) are $1.68, also in 1000s.

For more information on the LM2660 or LM2661, visit our website at http://www.national.com/pf/LM/LM2660.html.

National Semiconductor Corporation, a Fortune 500 Company, produces system-on-a-chip silicon solutions for the information highway, based on its leadership in analog and mixed signal technologies. National is headquartered in Santa Clara, California, and focuses on the communications, personal systems and consumer markets. In March 1997 National sold its Fairchild Semiconductor businesses and now has 12,300 employees worldwide with annual sales of approximately $2.0 billion. Additional company and product information is available on the World Wide Web at www.national.com.