The LTC3553-2 is a micropower, highly integrated power management and battery charger IC for single-cell Li-Ion/Polymer battery applications. It includes a PowerPath manager with automatic load prioritization, a battery charger, an ideal diode and numerous internal protection features. Designed specifically for USB applications, the LTC3553-2 power manager automatically limits input current to a maximum of either 100mA or 500mA. Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the selected input current limit. The LTC3553-2 also includes a synchronous buck regulator, an always-on low dropout linear regulator (LDO), and a pushbutton controller. With all supplies enabled in standby mode, the quiescent current drawn from the battery is only 12μA. The LTC3553-2 is available in a 3mm × 3mm × 0.75mm 20-pin QFN package.OptionsLDOPGOODHard Reset TimeLTC3553ON/OFF ControlNo5 secondsLTC3553-2Always OnYes14 secondsApplicationsUSB-Based Handheld ProductsPortable Li-Ion/Polymer Based Electronic DevicesWearable ElectronicsLow Power Medical Devices