BQ2023

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 uV. 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.