Patent ID: 9170621
Filing Date: 2015-10-27
Classification: G06F,H02J

Abstract:
1. A power supply device for providing a maintenance voltage at an output terminal to a system chip of a system comprising: a first battery for providing a battery voltage; a capacitor for storing a capacitor voltage; a charging circuit coupled to the capacitor; and a monitoring circuit for detecting the battery voltage and the capacitor voltage, wherein the monitoring circuit detects whether the battery voltage is less than a first threshold and whether the capacitor voltage is larger than a second threshold and generates a control signal according to the determination result, and wherein when the monitoring circuit detects that the battery voltage is less than the first threshold and the capacitor voltage is not larger than the second threshold, the monitoring circuit asserts the control signal to control the charging circuit to charge the capacitor; wherein when the monitoring circuit detects that the battery voltage is less than the first threshold and the capacitor voltage is larger than the second threshold, the monitoring circuit de-asserts the control signal to control the charging circuit not to charge the capacitor.