Low common mode noise transformers and switch-mode DC-DC power converters

An interleaved LLC power converter, comprising:

• one or more input terminals for receiving an input voltage from a voltage source;
• one or more output terminals for supplying an output voltage to a load;
• a first LLC converter including a first transformer and a first spacer, the first transformer coupled between the input and output terminals, the first transformer including a first plurality of winding sets each including a primary winding and a secondary winding magnetically coupled with one another, the first spacer positioned to separate an adjacent pair of the first plurality of winding sets, the primary windings of the first plurality of winding sets connected in series and the secondary windings of the first plurality of winding sets connected in parallel;
• and
• a second LLC converter interleaved with the first LLC converter, the second LLC converter including a second transformer and a second spacer, the second transformer coupled between the input and output terminals, the second transformer including a second plurality of winding sets each including a primary winding and a secondary winding magnetically coupled with one another, the second spacer positioned to separate an adjacent pair of the second plurality of winding sets, the primary windings of the second plurality of winding sets connected in series and the secondary windings of the second plurality of winding sets connected in parallel.