Power supply unit for improved low-load efficiency

A method, comprising:

• receiving, by a voltage rectifier/voltage doubler stage of a power supply unit, an alternating current input;
• providing, by the voltage rectifier/voltage doubler stage, a direct current output;
• coupling a bulk capacitor stage between the direct current output;
• configuring the voltage regulator/voltage double stage as a full-wave synchronous voltage rectifier when an input voltage of the alternating current input is above a threshold voltage;
• and
• configuring the voltage regulator/voltage double stage is configured as a full-wave synchronous voltage doubler when the input voltage is below the threshold voltage.

A power supply unit for an information handling system, the power supply unit comprising:

• a voltage rectifier/voltage doubler stage configured to receive an alternating current input and to provide a direct current output, the voltage rectifier/voltage doubler stage including:
• a first element having a first contact type coupled to a positive side of the alternating current input, and having a second contact type couple to a positive side of the direct current output;
• a second element having the first contact type coupled to a negative side of the direct current output, and having the second contact type coupled to the positive side of the alternating current input;
• a third element having the first contact type coupled to the negative side of the alternating current input, and having the second contact type coupled to the positive side of the direct current output;
• and
• a fourth element having the first contact type coupled to the negative side of the direct current output, and having the second contact type coupled to the negative side of the alternating current input;
• a bulk capacitor stage coupled between the direct current output, the bulk capacitor including a first capacitor and a second capacitor, wherein a first terminal of the first capacitor is coupled to the positive side of the direct current output, a second terminal of the first capacitor is coupled to a first terminal of the second capacitor, and a second terminal of the second capacitor is coupled to the negative side of the direct current output;
• and
• a switch having a first terminal coupled to a negative side of the alternating current input and a second terminal coupled to the second terminal of the first capacitor and to the second terminal of the second capacitor;
• wherein when an input voltage of the alternating current input is above a threshold voltage, the voltage regulator/voltage double stage is configured as a full-wave synchronous voltage rectifier, and when the input voltage is below the threshold voltage, the voltage rectifier/voltage doubler stage is configured as a full-wave synchronous voltage doubler.