National Semiconductor Extends Its Switched Capacitor Voltage Converter Family With Introduction Of Industry’s First 200-MilliAmp Output Converter in an SO-8 Package

July 22, 1997 - With the introduction of the LM2662 and LM2663 charge-pump voltage converters, National Semiconductor Corporation® today doubled the current-output generated by switched capacitors in an SO-8 surface-mount package. Both new ICs are rated 200 mA output current, with a typical output impedance of just 3.5 ohms. Unlike other types of switchers, switched capacitor circuits require no external inductor.

"National’s advanced process technology has made this high performance possible in an SO-8 package," noted Venkatesh Shan, National's power management marketing manager. "We’ve not only doubled our own current output, but now offer twice that of any competitor as well," he added.

The LM2662 and LM2663 convert a range of supply voltages from 1.5V to 5.5V at a typical efficiency of >86%. The low output impedance of just 3.5 ohms limits the voltage droop to 0.35V at 100mA. With an operating current of only 300 microamps and operating efficiency greater than 90% at most loads, both devices are ideal for a variety of portable applications. The LM2662/63 are designed for use in a variety of handheld battery-operated equipment in the PC and wireless markets, including PCMCIA cards and hard disk drives.

A frequency control pin on the LM2662 permits the designer to select oscillator frequencies of either 20kHz or 150kHz. Frequency of the LM2663 is set at 150kHz. The LM2663 also includes a low-current shutdown mode that disables the device and reduces the quiescent current to 10 microamps. Switched capacitors generate negative power rails from positive supplies or operate as a positive voltage doubler. Although two low-cost capacitors are required to provide the output current, the LM2662/63 does not require the external inductor and does not generate high EMI associated with inductor-based switchers, making it ideal for use in space-constrained portable designs.

Price and Availability
The LM2662M and LM2663M (SO-8 package) are priced at $2.10 each in 1000-piece lots and are available in production quantities.

For more information on the LM2662 or LM2663, visit our website at http://www.national.com/pf/LM/LM2662.html or http://www.national.com/pf/LM/LM2663.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. National has annual sales of approximately $2 billion and 12,000 employees worldwide.

Additional company and product information is available on the World Wide Web at www.national.com.