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.