SE9017 电源IC 移动电源IC

se9017 is a complete constant-current & constant voltage linearcharger for single cell ithium-ion and lithium-polymerbatteries.  its sot-23 package and low external componentcount make se9017 ideally suited for portable applications. furthermore, the se9017 is specifically designed to work within usbpower specification.   at the same time, se9017 can alsobe used in the standalone lithium-ion and lithium-polymer batterychargers. no external sense resistor is needed, and no blockingdiode is required due to the internal mosfetarchitecture. thermal feedback regulates the charge current to limit the dietemperature during high power operation or high ambienttemperature.   the charge voltage is fixed at 4.2v, andthe charge current can be programmed externally with a singleresistor.  the se9017 automatically terminates the chargecycle when the charge current drops to 1/10th the programmed valueafter the final float voltage is reached.   when theinput supply (wall adapter or usb supply) is removed, the se9017automatically enters a low current stage, dropping the batterydrain current to less than 2ua.   the se9017 can be putinto shutdown mode, reducing the supply current to 20ua.