DALLAS Dallas Semiconductor says that its DS2438 smart-battery monitor chip makes battery-management features formerly the domain of high-end systems cost-effective for portable products, such as cellular phones, two-way radios, camcorders and PDAs.
The chip stores battery-specific data and tracks battery parameters, including temperature, voltage, current and remaining charge. "With a DS2438 inside the battery pack, the portable system can identify the pack and configure itself to safely and accurately charge and monitor the battery," said Amy Gebrian, product manager.
The DS2438 provides battery data and battery measurements to the host-system's processor, where charge-control and remaining-charge algorithms execute in software. The company's 1-Wire network technology enables the pack-resident DS2438 to communicate with portable products over a single wire, thus minimizing connector cost and maximizing reliability.
The DS2438 provides 40 bytes of nonvolatile E2PROM memory for storage of battery-specific data. A portable product can read this memory over the 1-Wire network to identify the chemistry, capacity and construction of the battery pack and configure itself for that particular battery.
In addition to data storage, the DS2438 also provides a complete set of battery instrumentation. It measures battery temperature with 0.03 degrees C resolution and battery voltage with 10-mV resolution. The device also measures battery current with 10-bit resolution and integrates current over time to facilitate fuel gauging. A built-in offset-cancellation feature improves current measurement accuracy over previous devices.
The DS2438 is available now in an eight-pin SOIC package and will soon be available in flip-chip form as well. It is priced at $1.15 each in lots of 10,000. An evaluation kit, the DS2438K, is also offered.
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EETInfo No. 604