Standalone 1-cell, 0.5-A Li-ion battery charger w/ synchronous buck converter,output adjustable

The bq25015/7 are highly integrated charge and power management devices targeted at space-limited bluetooth applications. The bq25015/7 devices offer integrated power FET and current sensor for charge control, reverse blocking protection, high accuracy current and voltage regulation, charge status, charge termination, and a highly efficient and low-power dc-dc converter in a small package.

The bq25015/7 devices charge the battery in three phases: conditioning, constant current and constant voltage. Charge is terminated based on minimum current. An internal charge timer provides a backup safety feature for charge termination. The bq25015/7 automatically re-starts the charge if the battery voltage falls below an internal threshold. The bq25015/7 automatically enters sleep mode when VCC supply is removed.

The integrated low-power high-efficiency dc-dc converter is designed to operate directly from a single-cell Li-ion or Li-Pol battery pack. The output voltage is either adjustable from 0.7 V to VBAT, or fixed at 1.8 V (bq25017) and is capable of delivering up to 300-mA of load current. The dc-dc converter operates at a synchronized 1 MHz switching frequency allowing for the use of small inductors.