Compact power transformer components, devices, systems and methods

• US 8,258,911 B2
• Filed: 12/01/2010
• Issued: 09/04/2012
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Fouquet, Julie E.
• Primary Examiner(s): Musleh, Mohamad
• Assistant Examiner(s): LIAN, MANG TIN BIK
• Application Number:
  US12/957,446
• Publication Number:
  US 20110075449A1
• Time in Patent Office: 643 Days
• Field of Search: 336/200, 336/223, 336/232, 336/170, 363/21.01, 363/15.82, 363/109, 363/140
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 19/08 Transformers having magnetic bias, e.g. for handling pulses
• CPC Class Codes: H01F 2019/085 Transformer for galvanic isolation
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/52 One-way transmission networks, i.e. unilines

Abstract

Disclosed herein are various embodiments of compact coil power transformers configured to provide high voltage isolation and high voltage breakdown performance characteristics in small packages. Compact coil transformers are provided across which power may be transmitted and received by primary and secondary coils disposed on opposing sides of a substrate without high voltage breakdowns occurring therebetween. At least portions of the compact coil transformer are formed of an electrically insulating, non-metallic, non-semiconductor, low dielectric loss material. The compact coil transformers may be formed in small packages using, by way of example, printed circuit boards, flex circuits, lead frames, CMOS and other fabrication and packaging processes.

Claims

1. A power transformer, comprising:

first and second electrically insulating solid non-glass substrates comprising an electrically insulating, non-metallic, non-semiconductor low dielectric loss material, each substrate comprising opposing upper and lower surfaces;

a power amplifier circuit configured to receive an input DC power signal and convert the DC power signal into an AC power signal;

a first transmitting coil disposed upon or in the upper surface of the first substrate;

a second receiving coil disposed upon or in the lower surface of the first substrate;

a third receiving coil disposed upon or in the lower surface of the second substrate;

an input impedance matching circuit having a first input operably connected to the power amplifier circuit, and a first output operably connected to the first coil, the input impedance matching circuit being configured to match a first impedance of the first coil to an impedance of the power amplifier circuit; and

an output impedance matching circuit having second inputs operably connected to the second and third coils, and further comprising a second output, the output impedance matching circuit being configured to match an impedance of the second and third coils to a second impedance of an output circuit operably connected to the second output;

wherein the first coil is separated from the second coil by at least portions of the first substrate, the first and second coils are spatially arranged and configured respecting one another such that the AC power signals may be transmitted by the first coil to the second coil across a dielectric barrier comprising the non-semiconductor low dielectric loss material disposed therebetween, such material including at least portions of the first substrate;

wherein the first coil is separated from the third coil by at least portions of the second substrate, the first and third coils are spatially arranged and configured respecting one another such that the AC power signals may be transmitted by the first coil to the third coil across a dielectric barrier comprising the non-semiconductor low dielectric loss material disposed therebetween, such material including at least portions of the second substrate, and further wherein each of the first and second substrates has a thickness between upper and lower surfaces thereof ranging between about 0.5 mils and about 25 mils, between about 1 mil and about 25 mils, or between about 1.5 mils and about 25 mils.

2. The power transformer of claim 1, wherein the first and second substrates are generally planar.

3. The power transformer of claim 1, wherein the first and second substrates have a dielectric loss tangent at room temperature that is less than or equal to 0.05.

4. The power transformer of claim 1, wherein the first and second substrates have a dielectric loss tangent at room temperature that is less than or equal to 0.03.

5. The power transformer of claim 1, wherein the first and second dielectric barriers each exceed about 1 mil in thickness.

6. The power transformer of claim 1, wherein a breakdown voltage between the first coil and the second coil, or between the first coil and the third coil, exceeds about 2,000 volts RMS.

7. The power transformer of claim 1, wherein the power amplifier circuit is a Class E amplifier circuit.

8. The power transformer of claim 1, wherein the output circuit comprises a rectifier and a low-pass filter.

9. The power transformer of claim 1, wherein the output circuit comprises a voltage controller circuit.

10. The power transformer of claim 1, wherein the output circuit comprises a converter circuit.

11. The power transformer of claim 1, wherein the AC power signal has a frequency ranging between 9 MHz and 1.1 GHz.

12. The power transformer of claim 1, wherein the substrate material further comprises a material selected from the group consisting of one or more of beryllium, fiberglass, glass, ceramic, polyimide, polyimide film, a polymer, an organic material, a flex circuit material, epoxy, epoxy resin, a printed circuit board material, PTFE and glass, PTFE and ceramic, PTFE, glass and ceramic, plastic and thermoset plastic.

13. The power transformer of claim 1, wherein the power coil transformer comprises a plurality of layers in addition to the first and second substrates, at least one of the layers comprising the low dielectric loss material.

14. The power transformer of claim 1, wherein the breakdown voltage between the first coil and the second coil, or between the first coil and the third coil, exceeds about 2,000 volts RMS when applied over a time period of about one minute, exceeds about 2,000 volts RMS when applied over a time period of about six minutes, or exceeds about 2,000 volts RMS when applied over a time period of 24 hours.

15. The power transformer of claim 1, wherein the breakdown voltage between the first coil and the second coil, or between the first coil and the third coil, exceeds about 5,000 volts RMS when applied over a time period of about one minute, exceeds about 5,000 volts RMS when applied over a time period of about six minutes, or exceeds about 5,000 volts RMS when applied over a time period of 24 hours.