ISOLATED DIGITAL TRANSMISSION WITH IMPROVED EMI IMMUNITY

• US 20140119082A1
• Filed: 10/26/2012
• Published: 05/01/2014
• Est. Priority Date: 10/26/2012
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: MUECK, Michael, GLIBBERY, Adam
• Granted Patent: US 9,583,948 B2
• Time in Patent Office: Days
• US Class Current: 363/106
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H04L 25/0266 Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling

Abstract

Embodiments of the present invention may provide a circuit. The circuit may include a primary side, a secondary side, and an isolated energy transfer device electrically isolating the primary side and the secondary side. The primary side may include a first energy storage device coupled to a power source, a control system coupled to the first energy storage device for power, a second energy storage device, and a coupling system, coupled to the control system, to selectively couple the second energy storage device to the power source in a first phase and to selectively couple the second energy storage device to the primary side of the isolated energy transfer device during a second phase.

Claims

1. A circuit, comprising:

a primary side,

a secondary side, and

an isolated energy transfer device electrically isolating the primary side and the secondary side,

wherein the primary side comprises;

a first energy storage device coupled to a power source,

a control system coupled to the first energy storage device for power,

a second energy storage device, and

a coupling system, coupled to the control system, to selectively couple the second energy storage device to the power source in a first phase and to selectively couple the second energy storage device to the primary side of the isolated energy transfer device during a second phase.

2. The circuit of claim 1, wherein the isolated energy transfer device is a transformer circuit with a primary winding on the primary side and a secondary winding on the secondary side.

3. The circuit of claim 1, wherein the first energy storage device comprises at least one capacitor.

4. The circuit of claim 3, wherein the first energy storage device is coupled to the power source via at least one resistor.

5. The circuit of claim 1, wherein the second energy storage device comprises at least one capacitor.

6. The circuit of claim 5, wherein the coupling system is further configured to selectively couple a plurality of capacitors to the power source during the first phase and to selectively couple the plurality of capacitors to the primary side of the isolated energy transfer device sequentially during the second phase.

7. The circuit of claim 1, wherein the coupling system is further configured to selectively couple the second energy storage device to the primary side of the isolated energy transfer device in a bi-polar manner.

8. The circuit of claim 1, wherein the coupling system is further configured to selectively couple the second energy storage device to the power source in a bi-polar manner.

9. The circuit of claim 1, wherein the coupling system comprises at least one switch.

10. The circuit of claim 1, wherein the coupling system comprises a current source to selectively couple the second energy storage device to the power source.

11. The circuit of claim 1, wherein the coupling system comprises an amplifier to selectively couple the second energy storage device to the power source.

12. A method for transmitting data across an isolation barrier, comprising:

coupling a first energy storage device to a power source;

supplying power to a control system using the first energy storage device;

responsive to at least one control signal generated by the control system, coupling a second energy storage device to the power source during a charge phase, and coupling the second energy storage device to a primary side of an electrically isolating energy transfer device during a dump phase.

13. The method of claim 12, wherein coupling the second energy storage device to a power source during the charge phase includes charging a plurality of capacitors in the second energy storage device.

14. The method of claim 13, further comprising charging the plurality of capacitors during the charge phase and coupling the plurality of capacitors to the primary side of the electrically isolating energy transfer device sequentially during the dump phase.

15. The method of claim 13, further comprising charging the second energy storage device to a power supply voltage.

16. The method of claim 13, further comprising charging the second energy storage device to a control signal voltage.

17. The method of claim 12, further comprising coupling the second energy storage device to the primary side of the electrically isolating energy transfer device during the dump phase in a bi-polar manner.

18. The method of claim 12, further comprising coupling the second energy storage device to the power source during the charge phase in a bi-polar manner.