Multifunction Monitoring IC Designed to

Work With an Intelligent Host Controller:

– Provides Accurate State of Charge

Information for Rechargeable Batteries

– Enhances Power and Charge

Management in the System

Supply Operation Down to 2.4 V; Ideal for

Single-Cell Li-Ion or Li-Pol Applications

Communicates Over Single-Wire SDQ

Serial Interface

Resolves Signals Down to 3.05 μVh

High-Accuracy Coulometric Charge and

Discharge Current Integration

Differential Current Sense Input

Automatic and Continuous Offset

Calibration and Compensation

32 Bytes of General-Purpose RAM, 224

Bytes of FLASH, and 8 Bytes of Secure ID

ROM

Internal Temperature Sensor With 0.25°K

Resolution Eliminates the Need for an

External Thermistor

Programmable Digital Output Port

Battery-Pack Removal Detection Input

Places the IC in the Sleep Mode When

System Is Not Present

High-Accuracy Internal Timebase

Eliminates External Crystal Oscillator

Low Power Consumption:

– Operating: 40 μA

– Sleep: 1.5 μA

description

The bq2023 is an advanced battery monitoring IC

that accurately measures the charge and discharge

currents in rechargeable battery packs.

Intended for pack integration, the bq2023

contains all the necessary functions to form the

basis for an accurate battery gas gauge in cellular

phones, PDAs, or other portable products.

Gas gauging is accomplished by coulomb counting (i.e., measuring the charge input to and subsequently

removed from the battery). The bq2023 achieves that by measuring the differential voltage drop across a

low-value series sense resistor between the negative terminal of the battery and the battery-pack negative

contact. An internal voltage-to-frequency converter (VFC) converts this voltage into charge and discharge

counts. The VFC is capable of resolving signals down to 3.05 μV. By using the accumulated counts in the

charge, discharge, and self-discharge registers, an intelligent host controller can determine battery

state-of-charge information. To improve accuracy, the bq2023 continuously measures and compensates offset

errors in the VFC.

The bq2023 works with the host controller in the portable system to implement the battery management system.

The host controller interprets the bq2023 data and communicates meaningful battery data to the end-user or

power-management system. The SDQ single-wire bus architecture allows multiple bq2023s to exist on the

same communications node simultaneously.

The bq2023 provides 224 bytes of flash memory, 8-bytes of secure ID ROM, and 32 bytes of RAM. The

nonvolatile memory maintains formatted battery monitor information, identification codes, warranty information,

or other critical battery parameters while the battery is temporarily shorted or deeply discharged.