Patent ID: 8866339
Filing Date: 2014-10-21
Classification: H02J

Abstract:
1. A power management circuit, comprising: an input connected to a load and configured to receive a first direct current (DC) voltage from an external power circuit; a switch circuit connected between the load and a battery that provides an output voltage to the load; a first control unit configured to switch on or switch off the switch circuit, based on whether the input is supplied with the first DC voltage, and whether the output voltage of the battery is at or below a cut-off discharge voltage when the input is supplied with the first DC voltage; a voltage conversion circuit configured to convert the first DC voltage into a second DC voltage, the second DC voltage for charging the battery; and a second control unit configured to control whether the voltage conversion circuit converts the first DC voltage into the second DC voltage for charging the battery, based on whether the input is supplied with the first DC voltage, and whether the output voltage of the battery is equal to an end-of-charge voltage of the battery when the input is supplied with the first DC voltage.