DALLAS SEMICONDUCTOR CHIP SHRINKS BATTERY ELECTRONICS FOR MOBILE PHONES AND OTHER HANDHELD PRODUCTS
DALLAS, TEXAS-February 15, 2000-Dallas Semiconductor today announced its latest battery management chip, a device that greatly reduces the size and cost of battery electronics. The DS2438 Smart Battery Monitor makes battery management features formerly relegated to high-end systems cost-effective for a variety of portable products. The DS2438 stores battery-specific data and tracks battery parameters, including temperature, voltage, current and remaining charge.
 Product manager Amy Gebrian said, "A battery manager is necessary for safe and reliable battery charging. Reliable product operation also depends on the user having an accurate estimate of remaining battery charge. With a DS2438 inside the battery pack, the portable system can identify the pack and configure itself to safely, accurately charge and monitor the battery.
"The DS2438 is the latest chip designed for the Dallas Battery Management Architecture," she continued. "This design framework is based on the conviction that battery management is most cost-effective when battery pack devices do only those functions that must be done inside the pack, while all other functions are handled by existing system resources."
The DS2438 makes battery management cost-effective for portable products by providing battery data and battery measurements (which must be done in the pack) to the host-system's processor (an existing resource) where charge-control and remaining-charge algorithms are executed in software.
Dallas Semiconductor's 1-Wire® network technology enables the pack-resident DS2438 to communicate with portable products over a single wire. By using the 1-Wire network, products and battery packs can connect using just three electrical contacts--power, ground and data-minimizing connector cost and maximizing reliability. As a 1-Wire device, each DS2438 gives its battery pack a guaranteed-unique 64-bit net address, allowing multiple battery packs to be wired to a single bus but addressed individually. This in turn enables products to connect to two or more batteries simultaneously, supporting dual-battery operation or gang charging.
The DS2438 provides 40 bytes of nonvolatile EEPROM 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. Because this memory can be rewritten as needed, frequently changing data, such as date of last charge, can also be stored right inside the battery pack. EEPROM memory maintains stored data even when the battery is completely discharged or momentarily short-circuited.
In addition to data storage, the DS2438 also provides a complete set of battery instrumentation. The DS2438 measures battery temperature with 0.03°C resolution and battery voltage with 10mV 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. All of this measurement data is available to the portable product for charge-control, remaining-charge estimation and other battery monitoring tasks.
The DS2438 is available now in a space- and cost-saving 8-pin SOIC package and will soon be available in flip-chip form as well.
The DS2438 Smart Battery Monitor is ideal for cellular telephones, two-way radios, camcorders, digital cameras, PDAs and other handheld portable equipment. The DS2438 is in production now and costs $1.15 in 10K volumes. An evaluation kit, the DS2438K, is also available.
Dallas Semiconductor manufactures a broad line of mixed-signal, specialty semiconductors. The Company combines proprietary fab and circuit technologies to create innovative products that are sold to over 15,000 customers worldwide. Markets served include broadband telecommunications, wireless handsets, cellular base stations, secure Internet communications, networking, servers, data storage and a wide variety of industrial equipment.
|
