Signal isolator having inductive and capacitive signal coupling

• US 10,074,939 B1
• Filed: 08/08/2017
• Issued: 09/11/2018
• Est. Priority Date: 08/08/2017
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Briano, Robert A.
• Primary Examiner(s): Tran, Anthan
• Application Number:
  US15/671,357
• Time in Patent Office: 399 Days
• Field of Search: 307105, 365 20
• 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 2038/146 in combination with capacitive coupling
• CPC Class Codes: H01L 2224/02255 Shape of the auxiliary member
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2225/0651 Wire or wire-like electrical connections from device to substrate
• CPC Class Codes: H01L 2225/06531 Non-galvanic coupling, e.g. capacitive coupling
• CPC Class Codes: H01L 2225/06541 Conductive via connections through the device, e.g. vertical interconnects, through silicon via [TSV] manufacturing via connections per se H01L21/76898
• CPC Class Codes: H01L 23/485 consisting of layered constructions comprising conductive layers and insulating layers, e.g. planar contacts H01L23/4821, H01L23/4822, H01L23/4824, H01L23/4825 take precedence; materials H01L23/532, bond pads H01L24/02, bump connectors H01L24/10
• CPC Class Codes: H01L 23/49575 Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 23/5222 Capacitive arrangements or effects of, or between wiring layers other capacitive arrangements H01L23/642
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 24/03 Manufacturing methods
• CPC Class Codes: H01L 24/05 of an individual bonding area
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• 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: H01R 13/658 : High frequency shielding arrangements, e.g. against EMI [Electro-Magnetic Interference] or EMP [Electro-Magnetic Pulse] coaxial coupling devices specially adapted for high frequency H01R24/40; for flat or ribbon cable connectors H01R12/774; for coaxial cable H01R9/05
• CPC Class Codes: H04B 3/56 : Circuits for coupling, blocking, or by-passing of signals
• CPC Class Codes: H04L 25/0268 : with modulation and subsequent demodulation

Abstract

Methods and apparatus for a signal isolator having inductive and capacitive coupling. In embodiments, magnetic and electric fields are coupled by coils and capacitive plates. In embodiments, a floating plate can enable a top and bottom capacitive plate to be offset from each other.

Claims

1. A signal isolator, comprising:

a first coil having first and second ends;

a first plate coupled to the first end of the first coil;

a second plate coupled to the second end of the first coil, where the first and/or second plate is configured to be coupled to a drive circuit;

a second coil inductively coupled to the first coil;

a third plate capacitively coupled to the first plate;

a fourth plate capacitively coupled to the second plate;

at least one isolation layer between the first and second coils and between the first and second plates and the third and fourth plates;

a receive module including a first receive circuit coupled to the third and fourth plates and a second receive circuit to receive a signal on the second coil; and

a processing module to generate an output signal corresponding to a signal transmitted by the drive circuit from signals received by the first and second receive circuits.

2. The signal isolator according to claim 1, wherein the first and second coils are substantially planar coils.

3. The signal isolator according to claim 1, wherein the first plate and second plate corresponds to bond pads.

4. The signal isolator according to claim 1, wherein the first and/or second plates and the first coil are substantially co-planar.

5. The signal isolator according to claim 1, further including a floating plate between at least the first and third plates.

6. The signal isolator according to claim 5, wherein the floating plate is capacitively coupled with the first and third plates.

7. The signal isolator according to claim 5, wherein the floating plate distributes charge across the floating plate.

19. The signal isolator according to claim 1, further including a floating plate between at least the first and third plate means.

20. The signal isolator according to claim 19, wherein the floating plate is capacitively coupled with the first and third plate means.

21. The signal isolator according to claim 19, wherein the floating plate distributes charge across the floating plate.

8. A method for providing a signal isolator, comprising:

employing a first coil having first and second ends;

employing a first plate coupled to the first end of the first coil;

employing a second plate coupled to the second end of the first coil, where the first and/or second plate is configured to be coupled to a drive circuit;

employing a second coil inductively coupled to the first coil;

employing a third plate capacitively coupled to the first plate;

employing a fourth plate capacitively coupled to the second plate;

employing at least one isolation layer between the first and second coils and between the first and second plates and the third and fourth plates;

employing a receive module including a first receive circuit coupled to the third and fourth plates and a second receive circuit to receive a signal on the second coil; and

employing a processing module to generate an output signal corresponding to a signal transmitted by the drive circuit from signals received by the first and second receive circuits.

9. The method according to claim 8, wherein the first and second coils are substantially planar coils.

10. The method according to claim 8, wherein the first plate and second plate correspond to bond pads.

11. The method according to claim 8, wherein the first and/or second plates and the first coil are substantially co-planar.

12. The method according to claim 8, further including a floating plate between at least the first and third plates.

13. The method according to claim 12, wherein the floating plate is capacitively coupled with the first and third plates.

14. The method according to claim 12, wherein the floating plate distributes charge across the floating plate.

15. A signal isolator, comprising:

a first coil means;

a first plate means for capacitive coupling coupled to the first coil means;

a second plate means coupled to the first coil means, where the first and/or second plate means is configured to be coupled to a drive circuit;

a second coil means inductively coupled to the first coil means;

a third plate means capacitively coupled to the first plate means;

a fourth plate means capacitively coupled to the second plate means;

at least one isolation layer between the first and second coil means and between the first and second plate means and the third and fourth plate means;

a receive means including a first receive circuit coupled to the third and fourth plate means and a second receive circuit to receive a signal on the second coil means; and

a processing means to generate an output signal corresponding to a signal transmitted by the drive circuit from signals received by the first and second receive circuits.

16. The signal isolator according to claim 15, wherein the first and second coil means are substantially planar coils.

17. The signal isolator according to claim 15, wherein the first plate means and second plate means correspond to bond pads.

18. The signal isolator according to claim 15, wherein the first and/or second plates means and the first coil are substantially co-planar.