NATIONAL SEMICONDUCTOR ANNOUNCES SINGLE CHIP TO PRECISELY MANAGE CHARGING OF THREE MOST POPULAR BATTERY TYPES

Space-Saving LM3647 Universal Battery Charger Speeds Design Time, Cuts Cost, Reduces Inventory for Portable System OEMs

February 16, 2000- National Semiconductor Corporation (NYSE:NSM) today announced the LM3647 Universal Battery Charger, a single-chip solution for portable products that precisely manages recharging of the three most widely-used battery types: nickel-cadmium (Ni-Cd), nickel metal hydride (Ni-MH) and lithium-ion (Li-Ion). The LM3647 is designed as a flexible way to reduce design time, lower cost and cut inventory for designers of battery charging systems for portable consumer electronics, audio/video equipment, power tools, portable point-of-sale devices, personal convenience products and desktop chargers.

"By simply selecting the corresponding pin, a designer can easily choose the right battery type for a product without worrying about the intricate and very different charging characteristics of the three battery chemistries. The LM3647 automatically does that to optimize charge, maximize life and prevent battery damage," said Venkatesh Shan, marketing director for National's Power Management group. "Detecting and managing three battery types in one chip saves designers time and money. It also means that customers only need to stock one type of charge management IC to meet their battery needs."

The first of its kind, the new LM3647 strengthens National's Power Management portfolio of leading power and battery management products. Recognizing different battery types is vitally important because each battery has different charging characteristics and cell voltage levels. Nickel-based batteries, for example, have a typical cell voltage of 1.2V and are charged with a constant current, whereas Li-Ion cells can either have a cell voltage of 4.1V or 4.2 V and are charged with a constant voltage.

Key Battery Charging Features
The LM3647's soft-start feature prevents the premature termination of charging for nickel-based batteries, which can occur with badly conditioned batteries at the start of a fast charge cycle. The soft-start feature "eases" the battery into fast charge mode, by gradually increasing the charge current to the maximum fast charge rate. The LM3647 also supports the option to monitor the temperature of a battery pack or cell. If the battery temperature is not within safe operating limits (either too cold or too hot), charging is suspended. To extend battery lifetime, the LM3647 features an auto-adaptive fast charge that senses a battery's voltage level - and optionally the temperature - to select the appropriate charge current based on the battery's condition and state of recharge. The LM3647 provides different currents for fast charge, topping charge and maintenance charge. The maximum charge current rate can be manually selected via an external resistor. Terminating fast charge can be handled by delta T(emperature)/t(ime), negative delta V or peak voltage detection. A maximum temperature and charge time can be selected as backup termination methods.

Additionally, the LM3647 dynamically detects battery insertion and removal, and short circuits and bad batteries, with no extra hardware. It also supports the changing of battery packs of one to eight cells of Ni-Cd and Ni-MH batteries and up to one to four cells of Li-ion packs.

Pricing and Availability
Available now, the LM3647 is priced at $2.84 each in 1000-unit quantities. It is housed in a space-saving 20-pin small-outline (SO) package. For more information on the LM3647, visit National's Web site at http://www.national.com/pf/LM/LM3647.html, or contact National's Customer Response Group at 1-800-272-9959.

About National Semiconductor
National Semiconductor provides system-on-a-chip solutions for the information age. Combining real-world analog and state-of the-art digital technology, the company's chips lead many sectors of the personal computer, communications, and consumer markets. With headquarters in Santa Clara, California, National reported sales of $2 billion for its last fiscal year and has about 10,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.