Wake-up circuits, devices and methods for galvanic isolators

• US 8,629,714 B2
• Filed: 06/25/2009
• Issued: 01/14/2014
• Est. Priority Date: 06/25/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Ng, Gek Yong, Seet, Peng Siang, Chow, Fun Kok
• Primary Examiner(s): LUU, AN T
• Application Number:
  US12/491,354
• Publication Number:
  US 20100329363A1
• Time in Patent Office: 1,664 Days
• Field of Search: 327544-545, 709202-203, 340/693.3, 340/286.2
• US Class Current: 327/544
• CPC Class Codes: H04B 3/00 Line transmission systems combined with near-field transmission systems H04B5/00
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

According to one embodiment, there is provided a method of reducing the amount of power consumed by a galvanic isolator. A transmitter transmits a wake-up signal to a receiver located across an isolation medium when the transmitter is ready or preparing to transmit data or power signals to a receiver, which is operably connected to a sensing circuit. The sensing circuit receives the wake-up signal through the isolation medium, which may be operably connected to and powered substantially continuously or intermittently by a first power source. In response to the sensing circuit receiving the wake-up signal, the receiver is powered up from a sleep mode to an operating mode. After a period of time t_RDY has passed since the wake-up signal was transmitted, a signature pattern is transmitted from the transmitter to the sensing circuit through the isolation medium. Next, the sensing circuit or the receiver verifies the validity of the signature pattern. If the signature pattern is determined at to be valid, the receiver is enabled to receive the data or power signals from the transmitter. The transmitter then transmits the data or power signals from the transmitter through the isolation medium to the receiver.

Claims

1. A method of reducing the amount of power consumed by a galvanic isolator, comprising:

transmitting a wake-up signal across an isolation medium from a transmitter when the transmitter is ready or preparing to transmit data or power signals to a receiver operably connected to a sensing circuit;

receiving, with the sensing circuit, the wake-up signal through the isolation medium;

in response to the sensing circuit receiving the wake-up signal, powering the receiver up from a sleep mode to an operating mode;

after a period of time t_RDY has passed since the wake-up signal was transmitted, transmitting a signature pattern from the transmitter to the sensing circuit through the isolation medium;

verifying, with the sensing circuit or the receiver, the validity of the signature pattern and, if the signature pattern is determined to be valid, enabling the receiver to receive the data or power signals;

transmitting the data or power signals from the transmitter through the isolation medium, and

receiving, with the receiver, the data or power signals.

2. The method of claim 1, wherein the sensing circuit is operably connected to and powered substantially continuously by a first power source.

3. The method of claim 1, wherein the sensing circuit is operably connected to and powered intermittently by a first power source.

4. The method of either claim 2 or claim 3, wherein the first power source is independent from a second power source operably connected to, and configured to power, the receiver.

5. The method of either claim 2 or claim 3, wherein the first power source is configured to power both the sensing circuit and the receiver.

6. The method of claim 1, further comprising transmitting an end-of-transmission code from the transmitter to the sensing circuit after all the data or power signals have been transmitted to the receiver.

7. The method of claim 6, further comprising powering down the receiver from the operating mode to the sleep mode in response to the end-of-transmission code being received by the sensing circuit.

8. The method of claim 1, further comprising powering down the receiver from the operating mode to the sleep mode after a predetermined period of time has passed without any data or power signals being transmitted to the receiver by the transmitter.

9. The method of claim 1, further comprising powering down the receiver from the operating mode to the sleep mode after a predetermined period of time if the signature pattern is determined to be invalid.

10. The method of claim 1, wherein the isolation medium is capacitive, magnetic or optical.

11. The method of claim 1, further comprising transmitting the wake-up signal, the signature pattern, and the data and power signals through a single channel.

12. The method of claim 1, further comprising time-multiplexing the wake-up signal, the signature pattern, and the data and power signals through a single channel.

13. The method of claim 1, further comprising transmitting the wake-up signal, the signature pattern, and the data and power signals through two or more separate channels.

14. A reduced power consumption galvanic isolator, comprising:

a transmitter;

a receiver having a sensing circuit operably connected thereto;

a galvanic isolation medium located between the transmitter and the receiver;

wherein the transmitter is configured to transmit a wake-up signal across the isolation medium to the sensing circuit when the transmitter is ready or preparing to transmit data or power signals to the receiver, the sensing circuit is configured to receive the wake-up signal and cause the receiver to be powered up from a sleep mode to an operating mode when the wake-up signal is received, the transmitter further being configured to transmit a signature pattern to the sensing circuit or the receiver after a period of time t_RDY has passed since the wake-up signal was transmitted, the sensing circuit or the receiver being configured to verify the validity of the signature pattern and, if the signature pattern is determined to be valid, to enable the receiver to receive the data or power signals, the receiver being configured to consume a reduced amount of electrical power during the sleep mode with respect to the operating mode.

15. The reduced power consumption galvanic isolator of claim 14, wherein the sensing circuit is operably connected to and powered substantially continuously by a first power source.

16. The reduced power consumption galvanic isolator of claim 14, wherein the sensing circuit is operably connected to and powered intermittently by a first power source.

17. The reduced power consumption galvanic isolator of either claim 15 or claim 16, wherein the first power source is independent from a second power source operably connected to, and configured to power, the receiver.

18. The reduced power consumption galvanic isolator of either claim 15 or claim 16, wherein the first power source is configured to power both the sensing circuit and the receiver.

19. The reduced power consumption galvanic isolator of claim 14, wherein the receiver is further configured to re-enter the sleep mode after no data or power signals have been received thereby for a predetermined period of time.

20. The reduced power consumption galvanic isolator of claim 14, wherein the galvanic isolation medium is capacitive, magnetic or optical.

21. The reduced power consumption galvanic isolator of claim 14, wherein the transmitter is further configured to transmit an end-of-transmission code to the receiver when all the data or power signals have been transmitted to the receiver.

22. The reduced power consumption galvanic isolator of claim 14, wherein the receiver is further configured to switch from the operating mode to the sleep mode in response to the end-of-transmission code having been received.

23. The reduced power consumption galvanic isolator of claim 14, wherein the receiver is further configured to power down from the operating mode to the sleep mode after a predetermined period of time has passed without any data or power signals having been transmitted to the receiver by the transmitter.

24. The reduced power consumption galvanic isolator of claim 14, wherein the receiver is further configured to power down from the operating mode to the sleep mode after a predetermined period of time if the signature pattern is determined to be invalid.

25. The reduced power consumption galvanic isolator of claim 14, wherein the transmitter comprises an integrated circuit (IC), and the receiver comprises an IC.

26. The reduced power consumption galvanic isolator of claim 14, wherein the transmitter and receiver ICs are encapsulated or overmolded to form a single package.

27. The reduced power consumption galvanic isolator of claim 14, wherein the receiver and the transmitter are connected electrically to separate respective grounds.

28. The reduced power consumption galvanic isolator of claim 14, wherein the transmitter is configured to transmit differential signals therethrough.

29. The reduced power consumption galvanic isolator of claim 14, wherein the receiver is configured to receive differential signals therethrough.

30. The reduced power consumption galvanic isolator of claim 14, wherein at least portions of the transmitter or the receiver are fabricated using one or more of a CMOS process, a Bipolar-CMOS process, and a combined Bipolar-CMOS-DMOS (BCD) process.

31. The reduced power consumption galvanic isolator of claim 14, wherein the galvanic isolator is encapsulated at least partially in polyimide or plastic.

32. The reduced power consumption galvanic isolator of claim 14, wherein the transmitter or receiver further comprises a common mode rejection (CMR) circuit.

33. The reduced power consumption galvanic isolator of claim 14, wherein the galvanic isolation medium, the transmitter and receiver are configured to transmit the wake-up signal, the signature pattern, and the data and power signals through a single channel.

34. The reduced power consumption galvanic isolator of claim 14, wherein the galvanic isolation medium, the transmitter and receiver are configured to time multiplex the wake-up signal, the signature pattern, and the data and power signals through a single channel.

35. The reduced power consumption galvanic isolator of claim 14, wherein the galvanic isolation medium, the transmitter and receiver are configured to transmit the wake-up signal, the signature pattern, and the data and power signals through two or more separate channels.