The RT9526AGE is a linear single cell Li-ion Battery Charger with input over voltage protection and it is a fully integrated single cell Li-ion battery charger ideal for portable applications. The charger is capable of being powered up from AC adapter and USB (Universal Serial Bus) port inputs. The charger enters sleep mode when supplies are removed. This optimizes the charging task by using a control algorithm including preconditioning mode, fast charge mode and constant voltage mode. The charging task will remain in constant voltage mode to hold the battery in a full charge condition. The charge current can be programmed with an external resistor. The internal thermal feedback circuitry regulates the die temperature to optimize the charge rate under all ambient temperatures. The charger features 28V maximum rating voltage for VIN. Under-voltage protection and overvoltage protection are provided for the AC adapter supply.