BQ2060

• Provides Accurate Measurement of Available Charge in NiCd, NiMH, Li-Ion, and Lead-Acid Batteries
• Supports SBS Smart Battery Data Specification v1.1
• Supports the 2-Wire SMBus v1.1 Interface with PEC or 1-Wire HDQ16
• Reports Individual Cell Voltages
• Monitors and Provides Control to Charge and Discharge FETs in Li-Ion Protection Circuit
• Provides 15-Bit Resolution for Voltage, Temperature, and Current Measurements
• Measures Charge Flow Using a V-to-F Converter with Offset of Less Than 16 µV After Calibration
• Consumes Less Than 0.5 mW Operating
• Drives a 4- or 5-Segment LED Display for Remaining Capacity Indication
• 28-Pin 150-mil SSOP

The bq2060 SBS-compliant gas gauge IC for battery pack or in-system installation maintains an accurate record of available charge in rechargeable batteries. The bq2060 monitors capacity and other critical battery parameters for NiCd, NiMH, Li-ion, and lead-acid chemistries. The bq2060 uses a V-to-F converter with automatic offset error correction for charge and discharge counting. For voltage, temperature, and current reporting, the bq2060 uses an A-to-D converter. The onboard ADC also monitors individual cell voltages in a Li-ion battery pack and allows the bq2060 to generate control signals that may be used with a pack supervisor to enhance pack safety.

The bq2060 supports the smart battery data (SBData) commands and charge-control functions. It communicates data using the system management bus (SMBus) 2-wire protocol or the Benchmarq 1-wire HDQ16 protocol. The data available include the battery’s remaining capacity, temperature, voltage, current, and remaining run-time predictions. The bq2060 provides LED drivers and a push-button input to depict remaining battery capacity from full to empty in 20% or 25% increments with a 4- or 5-segment display.

The bq2060 works with an external EEPROM. The EEPROM stores the configuration information for the bq2060, such as the battery’s chemistry, self-discharge rate, rate compensation factors, measurement calibration, and design voltage and capacity. The bq2060 uses the programmable self-discharge rate and other compensation factors stored in the EEPROM to accurately adjust remaining capacity for use and standby conditions based on time, rate, and temperature. The bq2060 also automatically calibrates or learns the true battery capacity in the course of a discharge cycle from near full to near empty levels.

The REG output regulates the operating voltage for the bq2060 from the battery cell stack using an external JFET.