MAXIM DS2782E+

The DS2782 measures voltage, temperature and current, and estimates available capacity for rechargeable lithium ion and lithium-ion polymer batteries. Cell characteristics and application parameters used in the calculations are stored in onchip EEPROM. The available capacity registers report a conservative estimate of the amount of charge that can be removed given the current temperature, discharge rate, stored charge and application parameters. Capacity estimation reported in mAh remaining and percentage of full. The DS2782 operates directly from 2.5V to 4.5V and supports single cell Lithium-ion battery packs. The DS2782 accommodates multicell applications by adding a voltage regulator for VDD and voltage divider for VIN. Nonvolatile storage is provided for cell compensation and application parameters. Host side development of fuel-gauging algorithms is eliminated. On-chip algorithms and convenient status reporting of operating conditions reduce the serial polling required of the host processor. Additionally, 16 bytes of EEPROM memory are made available for the exclusive use of the host system and/or pack manufacturer. The additional EEPROM memory can be used to facilitate battery lot and date tracking and NV storage of system or battery usage statistics. Through its 2-Wire interface, the DS2782 gives the host system read/write access to status and control registers, instrumentation registers, and general-purpose data storage. The 7-bit slave address is field programmable, thus allowing up to 128 devices to be distinctly addressed by the host system. A unique, factory programmed 64-bit registration number (8-bit family code + 48-bit serial number + 8-bit CRC) option assures that no two parts are alike and enables absolute traceability.

• Precision Voltage, Temperature, and Current Measurement System
• Accurate Stable Internal Time Base
• Absolute and Relative Capacity Estimated from Coulomb Count, Discharge Rate, Temperature and Battery Cell Characteristics
• Accurate Warning of Low Battery Conditions
• Automatic Backup of Coulomb Count and Age Estimation to Nonvolatile (NV) EEPROM
• Gain and Tempco Calibration Allows the Use of Low-Cost Sense Resistors
• 24-Byte User EEPROM or 16-Byte User EEPROM and Unique 64-Bit ID
• Industry 2-Wire Interface with Programmable Slave Address
• Tiny 8-Pin TSSOP and 10-TDFN Packages
• Embed Easily in Thin Prismatic Cell Packs

• Digital Still Cameras
• Sub-Notebook Computers
• Handheld PC
• Data Terminals
• 3G Multimedia Wireless Handsets