bq2054

The bq2054 Lithium Ion Fast-Charge IC is designed to optimize charging of lithium ion (Li-Ion) chemistry batteries. A flexible pulse-width modulation regulator allows the bq2054 to control voltage and current during charging. The regulator frequency is set by an external capacitor for design flexibility. The switch-mode design keeps powerdissipationtoaminimum.


The bq2054 measures battery temperature using an external thermistor for charge qualification. Charging begins when power is applied or on batteryinsertion.


For safety, the bq2054 inhibits charging until the battery voltage and temperature are within configured limits. If the battery voltage is less than the low-voltage thresh-old, the bq2054 provides low-current conditioningofthebattery.


A constant current-charging phase replenishes up to 70% of the charge capacity, and a voltage-regulated phase returns the battery to full. The charge cycle terminates when the charging current falls below a user-selectable current limit. For safety, charging terminates after maximum time and is suspended if the temperature is outsidethepreconfiguredlimits.


The bq2054 provides status indications of all charger states and faults for accurate determination of the battery and charge system conditions.