POWER MANAGEMENT DEVICE AND METHOD FOR POWER CONVERSION

A power management device and a method for power conversion are provided. The power management device includes a buck circuit, a boost circuit, and a first and a second O-ring diode circuits. The buck circuit adjusts an input voltage to a first voltage. An embedded controller is activated and powered based on the first voltage. The boost circuit adjusts the first voltage to a second voltage. A system device is activated and powered based on the second voltage. The activated system device provides a first and second alternative power source on the first and second alternative power paths. After the system device is activated, the first and second O-ring diode circuits supply the first and second alternative power sources to the embedded controller and system device, respectively. The buck circuit and the boost circuit are turned off after the system device is activated and a predetermined delay time has passed.