Dual Input Li-Ion Charger With Dynamic Power Path, Output Cutoff At 6V, Vbat 4.2V

The bqTINY III-series of devices are highly integrated Li-ion linear chargers and system power-path management devices targeted at space-limited portable applications. The bqTINY III-series offer integrated USB-port and DC supply (AC adapter), power-path management with autonomous power-source selection, power FETs and Current Sensors high accuracy current and voltage regulation, charge status, and charge termination, in a single monolithic device.
The bqTINY III-series powers the system while independently charging the battery. This feature reduces the charge and discharge cycles on the battery, allows for proper charge termination and allows the system to run with an absent or defective battery pack. This feature also allows for the system to instantaneously turn on from an external power source in the case of a deeply discharged battery pack. The IC design is focused on supplying continuous power to the system when available from the AC, USB or battery sources.
The power select pin, PSEL, defines which input source is to be used first (primary source?AC or USB). If the primary source is not available, then the IC automatically switches over to the other secondary source if available or the battery as the last option. If the PSEL is set low, the USB input is selected first and if not available, the AC line is selected (if available) but programmed to a USB input limiting rate (100 mA/500 mA max). This feature allows the use of one input connector, where the host programs the PSEL pin according to what source is connected (AC adaptor or USB port).
The BQ24038 replaces USBPG
By Texas Instruments