GALVANIC ISOLATOR

• US 20100020448A1
• Filed: 06/02/2009
• Published: 01/28/2010
• Est. Priority Date: 08/28/2006
• 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., Baumgartner, Richard A., Ng, Gek Yong
• Granted Patent: US 8,385,043 B2
• Time in Patent Office: Days
• US Class Current: 361/1
• 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 19/04 Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range resonant circuits H03H
• 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: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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: H03F 2203/45008 the addition of two signals being made by a resistor addition circuit for producing the common mode signal
• CPC Class Codes: H03F 2203/45101 Control of the DC level being present
• CPC Class Codes: H03F 2203/45586 the IC comprising offset generating means
• CPC Class Codes: H03F 3/45192 Folded cascode stages
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03H 11/265 with adjustable delay
• CPC Class Codes: H03H 7/52 One-way transmission networks, i.e. unilines
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/75 for isolation purposes
• CPC Class Codes: H04L 25/0266 : Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling

Abstract

Galvanic isolators are disclosed herein. An embodiment of a galvanic isolator comprises a generally planar electrically insulating substrate comprising opposing first and second surfaces, the substrate comprising an electrically insulating, low dielectric loss material and having a transmitter coil disposed on the first surface and a receiving coil disposed on the second surface. A transmitter circuit is operably connected to the transmitter coil. The transmitter circuit comprises a first detector that detects a rising edge of an input signal; a first pulse generator that generates a plurality of first pulses upon detection of the rising edge; a second detector that detects a falling edge of the input signal; and a second pulse generator that generates a plurality of second pulses upon detection of the falling edge. A receiver circuit is operably connected to the second receiving coil. The receiver circuit generates a signal that is substantially similar to the input signal based on the first pulses and the second pulses.

Claims

1. A galvanic isolator, comprising:

a generally planar electrically insulating substrate comprising opposing first and second surfaces, the substrate comprising an electrically insulating, low dielectric loss material and having a transmitter coil disposed on the first surface and a receiving coil disposed on the second surface;

a transmitter circuit operably connected to the transmitter coil, said transmitter circuit comprising;

a first detector that detects a rising edge of an input signal;

a first pulse generator that generates a plurality of first pulses upon detection of said rising edge;

a second detector that detects a falling edge of said input signal;

a second pulse generator that generates a plurality of second pulses upon detection of said falling edge;

a receiver circuit operably connected to the second receiving coil;

wherein said receiver circuit generates a signal that is substantially similar to said input signal based on said first pulses and said second pulses.

2. The galvanic isolator of claim 1, wherein at least one of said first pulses overlaps at least a second one of said first pulses.

3. The galvanic isolator of claim 1, wherein the current generated by said first pulse generator remains substantially constant during generation of said first pulses.

4. The galvanic isolator of claim 1, wherein said input signal has a pulse length and wherein said first pulses are generated in a time that is less than half of said pulse length.

5. The galvanic isolator of claim 1 wherein said first edge detector generates a signal that enables said first pulse generator for a period that said first generator generates said first pulses.

6. The galvanic isolator of claim 1, wherein said first pulse generator comprises a plurality of delay circuits connected in series wherein a first of one of said delay circuits triggers a second one of said delay circuits.

7. The galvanic isolator of claim 6, wherein at least one of said delay circuits comprises two inverters connected in series.

8. The galvanic isolator of claim 1 and further comprising at least one driver connected between said first pulse generator and said transmitter coil.

9. The galvanic isolator of claim 8, wherein said at least one driver comprises at least one current mirror.

10. The galvanic isolator of claim 1 and further comprising a plurality of drivers, each of said plurality of drivers having an input and an output, the inputs of said drivers being connected to said pulse generators, the outputs of said drivers being connected in parallel and to said transmitter coil.

11. The galvanic isolator of claim 1, wherein said transmitter coil has a peak transmission frequency associated therewith and wherein said the spectrum of said pulses are substantially matched to said peak transmission frequency.

12. The galvanic isolator of claim 1, wherein the spectral components of said pulses are within the transmission bandwidth of said transmitter coil.

13. The galvanic isolator of claim 1, wherein the configuration of said transmitter coil is substantially similar to the configuration of said receiver coil.

14. The galvanic isolator of claim 1, wherein said transmitter coil is located on two metal layers connected by a first via, said first via having a first pad and a second pad associated therewith, wherein said first pad is located on a first metal layer and wherein a second pad is located on a second metal layer and wherein the portion of said transmitter coil located on said first metal layer has approximately 2⅜

turns of traces comprising said transmitter coil.

15. The galvanic isolator of claim 14, and further comprising:

a second via, said second via having a third pad associated therewith;

a first segment that is a mutual tangent segment extending between the circumference of said first pad and the circumference of said third pad chosen so that said first pad and said third pad lie on the same side of the segment; and

a second segment extending along at least a portion of a substantially straight trace, said substantially straight trace being located most proximate said first segment relative to other traces;

wherein the shortest distance between said first segment and said second segment is approximately 35 um.

16. The galvanic isolator of claim 1, and further comprising a first via and a second via, said first via having a first pad associated therewith, said second via has a third pad associated therewith, the shortest distance between the circumference of said first pad and the circumference of said third pad being approximately 35 um when viewed perpendicular to said galvanic isolator.

17. The galvanic isolator of claim 1, wherein said transmitter coil has a via pad associated therewith and wherein the diameter of said first pad is approximately 150 um.

18. The galvanic isolator of claim 1, wherein said transmitter coil has at least one trace associated therewith and wherein the width of said at least one trace approximately 35 um.

19. The galvanic isolator of claim 1, wherein said receiver comprises devices to check the validity of signals received from said receiver coil.

20. The galvanic isolator of claim 1, wherein said receiver is connected to a voltage clamping circuit.

21. The galvanic isolator of claim 1, wherein said receiver comprises devices to distinguish between the transmission of leading edges and trailing edges on said input signal.

22. The galvanic isolator of claim 1 wherein said receiver coil is coupled to an amplifier, wherein the input to said amplifier has a DC bias voltage applied thereto, wherein said DC bias voltage varies, and where said DC bias voltage is corrected to maintain a DC voltage at the output of said amplifier.