Power Converter Including an Autotransformer and Power Conversion Method

A method, comprising:

• receiving an input voltage and generating a chopper voltage with an alternating voltage level based on the input voltage by a chopper circuit;
• generating a tap voltage at a tap of an autotransformer coupled to the chopper circuit;
• receiving a plurality of voltage levels by a selector circuit, wherein at least one of the voltage levels is based on the tap voltage;
• and
• generating a selector output voltage based on the plurality of voltage levels by the selector circuit such that a voltage level of the selector output voltage alternates at a switching frequency between two selected ones of the plurality of voltage levels.

A power converter circuit, comprising:

• a chopper circuit configured to receive an input voltage and generate a chopper voltage with an alternating voltage level based on the input voltage and with a chopper frequency;
• an autotransformer comprising at least one tap, wherein the autotransformer is coupled to the chopper circuit and configured to generate a tap voltage at the at least one tap;
• a selector circuit configured to receive a plurality of voltage levels, wherein at least one of the voltage levels is based on the at least one tap voltage, and wherein the selector circuit is configured to generate a selector output voltage based on the plurality of voltage levels;
• and
• at least one series resonant circuit excited by the chopper voltage,
• wherein the at least one series resonant circuit includes a parasitic inductance of the autotransformer and wherein parameters of the at least one series resonant circuit are adapted to the chopper frequency such that the chopper frequency substantially equals a resonant frequency of the at least one series resonant circuit.

A method, comprising:

• receiving an input voltage and generating a chopper voltage with an alternating voltage level based on the input voltage and with a chopper frequency by a chopper circuit:
• receiving the chopper voltage and generating at least one tap voltage based on the chopper voltage by an autotransformer, and
• receiving a plurality of voltage levels by a selector circuit, wherein at least one of the voltage levels is based on the at least one tap voltage, and generating a selector output voltage based on the plurality of voltage levels by the selector circuit,
• wherein the chopper frequency substantially equals a resonant frequency of at least one series resonant circuit that includes a parasitic inductance of the autotransformer.