New Industry Products

National Semiconductor Debuts New LM3647 Universal Battery Charger

February 27, 2000 by Jeff Shepard

National Semiconductor Corp. (Santa Clara, CA) recently announced their new LM3647 universal battery charger. The LM3647 is a single-chip solution for portable products that is designed to precisely manage recharging NiCd, NiMH and lithium-ion batteries, the three most widely used battery types.

According to National, the LM3647 is designed as a flexible way to reduce design time, lower cost and lower 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. The LM3647's soft-start feature is designed to prevent 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 device also supports the option to monitor the temperature of a battery pack or cell.

To extend battery lifetime, the device features auto-adaptive charge and maintenance charge. The maximum charge-current rate can also be manually selected via an external resistor. The LM3647 dynamically detects battery insertion and removal, short circuits, and bad batteries, with no extra hardware. It also supports the charging of battery packs of one to eight cells of NiCd and NiMH batteries, and one to four cells of lithium-ion packs.

"Detecting and managing three battery types in one chip saves designers time and money," said Venkatest Shan, marketing director for National's power-management group. "It also means that customers only need to stock one type of charge-management IC to meet their battery needs."

The device is available in a 20-pin SO package. In quantities of 1,000, pricing for the LM3647 is $2.84 each and is currently available.