Noise cancellation for a magnetically coupled communication link utilizing a lead frame

• US 9,349,717 B2
• Filed: 07/16/2014
• Issued: 05/24/2016
• Est. Priority Date: 11/14/2012
• Status: Active Grant

• Current Assignee: Power Integrations Incorporated
• Original Assignee: Power Integrations Incorporated
• Inventors: Kung, David, Matthews, David Michael Hugh, Balakrishnan, Balu
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US14/332,743
• Publication Number:
  US 20140327108A1
• Time in Patent Office: 678 Days
• Field of Search: 455/333, 455/550.1, 455/41.1, 571/531, 571/676, 257/531, 257/666, 257/676
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 23/48 Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
• CPC Class Codes: H01L 23/49503 characterised by the die pad
• CPC Class Codes: H01L 23/4952 the additional leads being a bump or a wire
• CPC Class Codes: H01L 23/49541 Geometry of the lead-frame
• CPC Class Codes: H01L 23/49575 Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 28/10 Inductors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H04B 15/005 Reducing noise, e.g. humm, from the supply
• CPC Class Codes: H05K 7/14 Mounting supporting structure in casing or on frame or rack

Abstract

An integrated circuit package includes an encapsulation and a lead frame with a portion of the lead frame disposed within the encapsulation. The lead frame includes a first conductor having a first conductive loop and a third conductive loop disposed within the encapsulation. The third conductive loop is wound in a direction relative to the first conductive loop such that the first conductive loop is coupled out of phase with the third conductive loop. The lead frame also includes a second conductor galvanically isolated from the first conductor. The second conductor includes a second conductive loop disposed within the encapsulation proximate to the first conductive loop to provide a communication link between the first and second conductors.

Claims

1. An integrated circuit package, comprising:

an encapsulation; and

a lead frame, a portion of the lead frame disposed within the encapsulation, the lead frame including a first conductor formed in the lead frame having a first conductive loop and a third conductive loop disposed within the encapsulation, wherein the third conductive loop is wound in a direction relative to the first conductive loop such that the first conductive loop is coupled out of phase with the third conductive loop, wherein the lead frame further includes a second conductor formed in the lead frame galvanically isolated from the first conductor, wherein the second conductor includes a second conductive loop disposed within the encapsulation proximate to the first conductive loop to provide a communication link between the first and second conductors.

2. The integrated circuit package of claim 1, further comprising:

a first isolated control die including a first receive circuit coupled to the first conductor; and

a second isolated control die including a first transmit circuit coupled to the second conductor, wherein one or more control signals are communicated between the first and second isolated control dice through the communication link.

3. The integrated circuit package of claim 2 wherein the first isolated control die is mounted on and coupled to the first conductor of the lead frame.

4. The integrated circuit package of claim 3 further comprising a first bond wire coupled to the first conductor and the first isolated control die.

5. The integrated circuit package of claim 2 wherein the second isolated control die is mounted on the second conductor of the lead frame, wherein the second isolated control die is coupled to and completes the second conductive loop.

6. The integrated circuit package of claim 5 further comprising a second bond wire coupled to the second conductor and the second isolated control die.

7. The integrated circuit package of claim 2 wherein the first and second isolated control dice are coupled to respective external pin pads of the integrated circuit package.

8. The integrated circuit package of claim 1 wherein the integrated circuit package is subjected to an external magnetic field, wherein a magnitude of a first noise signal component induced in the first conductive loop in response to the external magnetic field is substantially equal to a magnitude of a second noise signal component induced in the third conductive loop in response to the external magnetic field.

9. The integrated circuit package of claim 1 wherein the integrated circuit package is subjected to an external magnetic field, wherein a first noise signal component is induced in the first conductive loop in response to the external magnetic field and a second noise signal component is induced in the third conductive loop in response to the external magnetic field, wherein a combination of the first and second noise signal components is substantially equal to zero.

10. The integrated circuit package of claim 1 wherein first and third conductive loops are disposed such that magnetically coupled signals induced in first and third conductive loops due to a changing magnetic field generated by current flow in the second conductive loop are additive.

11. The integrated circuit package of claim 1 wherein the first and third conductive loops are substantially the same size.