Embedded magnetic component transformer
An embedded magnetic component transformer includes first, second, and auxiliary electrical windings in an insulating substrate including conductive vias joined together by conductive traces. The first electrical windings are divided by a tap terminal into first and second winding portions, which are interleaved with one another and energized by separate transistors. Heat generated by the first and second winding portions is transferred more equally to the separate transistors. Equal or substantially equal path lengths between each of the transistors and the first electrical windings improve flux balance allowing the transistors to conduct for equal or substantially equal times during a switching cycle. Thus, the switching cycle of the embedded transformer is more symmetric with respect to each of the transistors and winding portions, improving the electrical characteristics of the transformer.
1. A power electronics device comprising:
an embedded transformer; and
first and second transistors; wherein
the embedded transformer includes:
an insulating substrate including a first side and a second side opposite the first side, and including a cavity therein, the cavity including an inner periphery and an outer periphery;
a magnetic core housed in the cavity and including a first section and a second section;
a first electrical winding, passing through the insulating substrate and disposed around the first section of the magnetic core; and
a second electrical winding, passing through the insulating substrate and disposed around the second section of the magnetic core; wherein
each of the first and second electrical windings includes:
upper conductive traces disposed on the first side of the insulating substrate;
lower conductive traces disposed on the second side of the insulating substrate;
inner conductive connectors passing through the insulating substrate adjacent an inner periphery of the magnetic core, the inner conductive connectors respectively defining electrical connections between respective ones of the upper conductive traces and respective ones of the lower conductive traces; and
outer conductive connectors passing through the insulating substrate adjacent an outer periphery of the magnetic core, the outer conductive connectors respectively defining electrical connections between respective ones of the upper conductive traces and respective ones of the lower conductive traces; wherein
the upper and lower conductive traces and inner and outer conductive connectors defining respective turns of the first and second electrical windings;
the first electrical winding includes:
a first end terminal and a second end terminal;
a tap terminal;
a first winding portion between the first end terminal and the tap terminal; and
a second winding portion between the second end terminal and the tap terminal; wherein
the first transistor energizes the first winding portion;
the second transistor energizes the second winding portion;
the first and second winding portions are energized alternately; and
at least one of the turns of the first winding portion is interleaved between the turns of the second winding portion.
2. The power electronics device of claim 1 , wherein all of the turns of the first winding portion are interleaved with the turns of the second winding portion.
3. The power electronics device of claim 1 , wherein the first winding portion includes a same number of turns as the second winding portion.
4. The power electronics device of claim 1 , wherein the tap terminal is located on an electrical path that is equidistant or substantially equidistant from each of the first end terminal and the second end terminal.
5. The power electronics device of claim 1 , wherein
the first transistor is electrically connected to the first end terminal via a first conducting portion;
the second transistor is electrically connected to the second end terminal via a second conducting portion; and
the power electronics device further includes:
a first electrical path extending from the first transistor, via the first conducting portion, the first end terminal, and the first winding portion, to the tap terminal; and
a second electrical path extending from the second transistor, via the second conducting portion, the second end terminal, and the second winding portion, to the tap terminal; wherein
lengths of the first and second electrical paths are equal or substantially equal.
6. The power electronics device of claim 1 , wherein
the first end terminal is located at a first angular position around the outer periphery of the cavity;
the second end terminal is located at a second angular position around the outer periphery of the cavity; and
the tap terminal is located at an angular position between the first and second angular positions.
7. The power electronics device of claim 1 , wherein
the first end terminal is located at a first angular position around the outer periphery of the cavity;
the tap terminal is located at a second angular position around the outer periphery of the cavity; and
the second end terminal is located at an angular position between the first and second angular positions.
8. The power electronics device of claim 1 , wherein one of the first and second electrical windings of the embedded transformer has fewer turns than the other one of the first and second electrical windings, and the upper and lower conductive traces of the one of the first and second electrical windings are wider than the upper and lower conductive traces of the other of the first and second electrical windings.
9. The power electronics device of claim 1 , further comprising:
an additional tap terminal located on the second electrical winding and including:
a third winding portion between a first end terminal of the second electrical winding and the tap terminal; and
a fourth winding portion between a second end terminal of the second electrical winding and the tap terminal.
10. The power electronics device of claim 9 , wherein at least one of turns of the third winding portion is interleaved between turns of the fourth winding portion.
11. The power electronics device of claim 10 , wherein all of the turns of the third winding portion are interleaved with the turns of the fourth winding portion.
12. The power electronics device of claim 9 , wherein the third winding portion includes a same number of turns as the fourth winding portion.
13. The power electronics device of claim 9 , wherein the additional tap terminal is located on an electrical path that is equidistant or substantially equidistant from each of the first end terminal of the second electrical winding and the second end terminal of the second electrical winding.
14. The power electronics device of claim 1 , wherein
the embedded transformer includes an auxiliary electrical winding operable to switch at least one of the first and second transistors;
the auxiliary electrical winding passes through the insulating substrate and disposed around the magnetic core; and
the auxiliary electrical winding includes:
upper conductive traces disposed on the first side of the insulating substrate;
lower conductive traces disposed on the second side of the insulating substrate;
inner conductive connectors passing through the insulating substrate adjacent the inner periphery of the magnetic core, the inner conductive connectors respectively defining electrical connections between respective ones of the upper conductive traces of the auxiliary electrical winding and respective ones of the lower conductive traces of the auxiliary electrical winding; and
outer conductive connectors passing through the insulating substrate adjacent the outer periphery of the magnetic core, the outer conductive connectors respectively defining electrical connections between ones of the respective upper conductive traces of the auxiliary electrical winding and respective ones of the lower conductive traces of the auxiliary electrical winding; wherein
the upper and lower conductive traces and inner and outer conductive connectors define respective turns of the auxiliary electrical winding.
15. The power electronics device of claim 1 , wherein the first and second transistors are positioned such that heat flow from the first and second electrical windings of the embedded transformer to the first transistor is equal or substantially equal to that from the first and second electrical windings of the embedded transformer to the second transistor.
16. The power electronics device of claim 1 , wherein the first and second transistors are positioned such that leakage inductance between the first transistor and the first and second electrical windings of the embedded transformer is equal or substantially equal to that between the second transistor and the first and second electrical windings of the embedded transformer.
17. A push-pull power transformer comprising the power electronics device of claim 1 .
18. The power transformer of claim 17 , further comprising a Royer circuit on an input side.
19. The power transformer of claim 17 , further comprising a synchronized rectifier on an output side.