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National Semiconductor Introduces Tiny USB/AC Battery Charger and Power Management IC for Portable Devices

Single-chip, Dual-input Battery Charger IC Features High Termination Accuracy and Advanced Safety Features

Jul 6, 2005

July 6, 2005 - National Semiconductor Corporation (NYSE:NSM), the worldwide leader in power management technology, today introduced a very small, single-chip, dual-input USB/AC battery charger and power management integrated circuit (IC) that safely charges and maintains single-cell Lithium-ion (Li-Ion) and Lithium-Polymer (Li-Polymer) batteries.  The LM3658 features a high termination accuracy of 1.5 percent that extends battery life, making it well suited for a variety of portable devices including personal digital assistants, MP3 players, digital still cameras, Internet appliances, instrumentation and smart phones.

"Today's portable systems demand short charge times, accurate voltage termination and reliable battery supervisory functions," said Gianluca Colli, director of integrated system products for National Semiconductor's Portable Power Products Group.  "The LM3658 Li-Ion battery charger IC delivers high value to the system designer by offering a cost effective and versatile solution coupled with optimum performance in a tiny 3 mm by 3 mm package."

The LM3658 charges and maintains a Li-Ion or Li-Polymer battery, drawing power from either a USB or an AC wall adapter and defaulting automatically to the AC wall adapter setting when both power sources are present.  The LM3658 requires few external components and features integrated PowerFETs, a current sensor, reverse-blocking protection and thermal regulation for advanced battery protection.

Advanced safety features include LED status indicators, safety timers and continuous temperature monitoring of the battery.  The LM3658 battery charger IC is packaged in a very small, thermally enhanced 10-lead LLP® package that measures 3 mm x 3 mm.

Key Technical Specifications of National’s LM3658 Battery Charger and Power Management IC
Programmed through an external resistor, the LM3658 allows charge currents from 50 mA to 1000 mA when operating from an AC wall adapter.  When the battery is charged using USB power, charge currents of 100 mA or 500 mA are pin-selectable.  The termination voltage is controlled to within 1.5 percent of 4.2V.  With an input voltage range of 2.5V to 6V, the LM3658 supports a maximum output current of one amp, and can be adjusted through an external resistor.  The internal power FETs are thermally regulated to obtain the most efficient charging rate for a given ambient temperature.

The device operates in five modes, including pre-qualification mode, constant-current mode, constant-voltage mode, top-off mode and maintenance mode.  Optimal battery management is obtained through thermal regulation, battery temperature measurement and multiple safety timers.  The LM3658 provides two open-drain outputs for LED status indication or connection to general-purpose onput/outputs (GPIOs).  For more information on the LM3658 or to order samples and an evaluation board, visit http://www.national.com/pf/LM/LM3658.html.

About National’s Power Management Products
National Semiconductor is the number one supplier of power management ICs with 14.1 percent market share, according to iSuppli’s 2005 voltage regulator/reference survey.  National’s power management revenue grew 37.3 percent in 2004 over the previous year, compared to 24 percent growth for the industry during the same time period.  National's innovative power management products include best-in-class linear regulators; power monitoring, control and reference ICs; and switching converters, such as high-voltage ICs for DC-DC conversion, switched capacitor converters, lighting management ICs and inductive switching converters.  National's WEBENCH® online design tool allows designers to select a power management product, create and analyze a design, and then build custom prototypes that can be delivered within 24 hours.  More information about National’s power management products is available at http://power.national.com.

Pricing and Availability
Available now, the LM3658 battery charger and power management IC is packaged in a thermally enhanced 10-lead LLP and priced at $1.50 in 1,000-unit quantities.  An evaluation board and lead-free package options are also available.

Note to Editors:  To view a high-resolution downloadable photo of this product, visit National’s photo gallery at http://www.national.com/company/pressroom/gallery/power.html.

About National Semiconductor
National Semiconductor, the industry's premier analog company, creates high performance analog devices and subsystems.  National's leading-edge products include power management circuits, display drivers, audio and operational amplifiers, communication interface products and data conversion solutions. National's key analog markets include wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial, and test and measurement applications. Headquartered in Santa Clara, California, National reported sales of $1.91 billion for fiscal 2005, which ended May 29, 2005.  Additional company and product information is available at www.national.com.