Core structure and interleaved DC-DC converter topology

A DC-DC converter, comprising:

• a DC-AC converter which converts a DC voltage to N AC drive voltages suitable for driving N half-bridge current doubler rectifiers (CDRs) in accordance with the symmetric modulation scheme, said AC drive voltages having a switching period Ts,
• an AC-DC converter comprising at least two half-bridge CDRs, each of which is driven with a respective one of said AC drive voltages and is arranged to provide two rectified output currents to an output node,
• a filter capacitor connected between said output node and a common node, and
• a load connected between said output node and said common node,
• said DC-AC converter arranged such that said AC drive voltages are phase-shifted by Ts/(2*N) such that the rectified output currents of said at least two CDRs are interleaved.

A DC-DC converter, comprising:

• a DC-AC converter which converts a DC voltage to first and second AC drive voltages suitable for driving respective half-bridge current doubler rectifiers (CDRs) in accordance with the symmetric modulation scheme, said AC drive voltages having a switching period Ts, said DC-AC converter comprising:
• positive and negative DC input voltage terminals for receiving a DC input voltage,
• first and second switches connected in series between said positive and negative DC input voltage terminals, the junction of said first and second switches being a first node,
• third and fourth switches connected in series between said positive and negative DC input voltage terminals, the junction of said third and fourth switches being a second node,
• first and second capacitors connected in series between said positive and negative DC input voltage terminals, the junction of said first and second switches being a third node,
• a first AC drive voltage taken between said first and third nodes and a second AC drive voltage taken between said second and third nodes, and
• a control circuit which operates said first, second, third and fourth switches to provide said first and second AC drive voltages such that they are phase-shifted by Ts/4 with respect to each other,
• an AC-DC converter comprising first and second half-bridge CDRs, each of which is driven with a respective one of said AC drive voltages such that said CDRs provide four interleaved rectified output currents to an output node, each of said CDRs comprising:
• first and second primary windings connected in series,
• first and second secondary windings connected together at said output node, said first and second secondary windings magnetically coupled to said first and second primary windings, respectively, said first and second primary windings and first and second secondary windings wound on a common core,
• a first switch circuit connected between said common node and the end of said first secondary winding opposite said output node, and
• a second switch circuit connected between said common node and the end of said second secondary winding opposite said output node,
• said first switch circuit arranged to conduct current when the voltage across said second switch circuit is positive with respect to said common node and the AC drive voltage applied across said first and second primary windings is positive, and said second switch circuit arranged to conduct current when the voltage across said first switch circuit is positive with respect to said common node and the AC drive voltage applied across said first and second primary windings is negative,
• said AC drive voltage applied across said series-connected first and second primary windings,
• a filter capacitor connected between said output node and a common node, and
• a load connected between said output node and said common node.