ISL6295
Low Voltage Fuel Gauge

Key Features

• Measures, maintains, and reports all critical rechargeable battery parameters with high accuracy
• Supports Lithium Ion and Lithium Polymer battery packs
• Current measurement with 16-bit (15-bit plus sign) integrating A/D accurate to less than ±0.5% error
• Calibrated temperature measurement accurate to within ±3°C absolute using
  on-chip temp sensor or external thermistor
• Accumulation of charge current, discharge current, temperature, and voltage in independent 32-bit registers
• 256-byte nonvolatile EEPROM stores factory programmed, measured, and
  user-defined parameters
• In-system offset calibration compensates for offset error in current measurement
• Industry standard SMBus/I²C™ compatible 2-wire communications interface
• SMBus V1.1 with PEC/CRC-8 communication
• -20°C to +85°C operating temperature range
• NTC pin can be configured as a thermistor input or GPIO
• GPAD pin can be configured as an independent A/D input or GPIO
• Flexible power operating modes allow low-power monitoring of battery conditions during system full operating and standby conditions:
• Run: Continuous Conversion; 85µA typ.
• Sample: Sample interval from 0.5-64s @ 45µA typ.
• Sample-Sleep: Sample interval from 0.5-138s min. @ 20µA typ.
• Shelf-Sleep mode reduces power consumption to pack storage conditions to 300nA typ., with automatic wake-up upon pack insertion.
• Pb-free plus anneal available (RoHS compliant)

Description

The ISL6295 is a cost-effective, highly accurate IC that measures, stores, and reports all of the critical parameters required for rechargeable battery monitoring with a minimum of external components. It precisely measures charge/ discharge current as well as voltage and temperature of a battery pack. In addition, the ISL6295 accurately accumulates both charge and discharge current as independent parameters. Temperature history can also be maintained for calculating self-discharge effects.

The ISL6295 integrates a highly accurate 16-bit (15-bit plus sign) integrating A/D converter that performs calibrated current measurement to within ±0.5% error. On-chip counters precisely track battery charge/discharge and temperature history. Also included are an on-chip voltage regulation circuit, non-crystal time base, and on-chip temperature sensor. The operating voltage range of the ISL6295 is optimized to allow a direct interface to a single cell Li-Ion/Li-Poly pack. 256 bytes of general-purpose nonvolatile EEPROM storage are provided to store factory programmed, measured, and user defined parameters.

Efficient communication is provided through an industry standard SMBus/I²C™ compatible 2-wire communications interface. This interface allows the host to determine accurate battery status for effective system power management and for communication to the end user. A battery management solution utilizing the ISL6295 delivers both space and total system component cost savings for a wide variety of battery operated applications.

Applications

• Notebook PC, PDAs, Hand Held Devices