FEATURES

· 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

DESCRIPTION

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.