Architecture for minimum loop current during ringing and caller ID

• US 6,975,723 B2
• Filed: 05/05/2003
• Issued: 12/13/2005
• Est. Priority Date: 04/22/1997
• Status: Expired due to Fees

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Scott, Jeffrey W., Krone, Andrew W., Welland, David R., Hein, Jerrell P., Sooch, Navdeep S.
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): SINGH, RAMNANDAN P
• Application Number:
  US10/429,795
• Publication Number:
  US 20030206626A1
• Time in Patent Office: 953 Days
• Field of Search: 37941302-41304, 379/399.01
• US Class Current: 379/413.02
• CPC Class Codes: H04L 25/0266 Arrangements for providing Galvanic isolation, e.g. by means of magnetic or capacitive coupling
• CPC Class Codes: H04L 25/06 Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
• CPC Class Codes: H04M 1/573 Line monitoring circuits for detecting caller identification
• CPC Class Codes: H04M 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 19/001 Current supply source at the exchanger providing current to substations
• CPC Class Codes: H04M 19/02 providing ringing current or supervisory tones, e.g. dialling tone or busy tone
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication system is provided which draws virtually no loop current during a ringing burst and only draws on-hook loop current during the caller ID field. More particularly, ringer burst circuitry may be powered from the user powered circuitry by the transmission of power across the isolation barrier rather than being powered from the phone line. Thus, loop current need not be drawn from the TIP/RING lines during ringer bursts. The isolation barrier may be a capacitive isolation barrier which allows bidirectional communication and extraction of power from signals transmitted across the barrier.

Claims

1. A communication system, comprising:

phone line side circuitry for coupling to phone lines, the phone line side circuitry being configured to provide an output signal for sending data to the phone lines;

powered side circuitry for coupling to the phone line side circuitry through an isolation barrier that comprises a plurality of isolation elements, the powered side circuitry being configured to be isolated from the phone lines in order to satisfy phone line isolation regulatory standards; and

phone line side integrated ringer circuitry within the phone line side circuitry, the phone line side integrated ringer circuitry drawing substantially no loop current from the phone line during ringing condition;

wherein the powered side circuitry is configured to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor;

wherein the phone line side circuitry is configured to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals;

wherein the powered side circuitry is further configured to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements; and

wherein the powered side circuitry and the phone line side circuitry are further configured so that power is capable of being provided from the powered side circuitry to the phone line side circuitry while still maintaining the isolation required by the phone line isolation regulatory standards.

2. The communication system of claim 1, further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry.

3. The communication system of claim 1, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

4. The communication system of claim 1, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.

5. The communication system of claim 1, wherein the phone line side circuitry and the powered side circuitry are configured to communicate across the isolation barrier through a digital signal.

6. The communication system of claim 5, further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry.

7. The communication system of claim 1, the phone line side integrated ringer circuitry operating from power supplied from across the isolation barrier.

8. The communication system of claim 7, further comprising:

the isolation barrier coupled between the phone line side circuitry and the powered side circuitry,

wherein the phone line side circuitry and the powered side circuitry are configured to communicate across the isolation barrier through a digital signal.

9. The communication system of claim 1, wherein said powered side circuitry is further configured to provide a clock signal to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor.

10. The communication system of claim 1, wherein the first digital differential signal includes both data information and control information.

11. A communication system, comprising:

phone line side circuitry for coupling to phone lines, the phone line side circuitry being configured to provide an output signal for sending data to the phone lines;

powered side circuitry for coupling to the phone line side circuitry through an isolation barrier that comprises a plurality of isolation elements, the powered side circuitry being configured to be isolated from the phone lines in order to satisfy phone line isolation regulatory standards; and

phone line side integrated ringer circuitry within the phone line side circuitry, the phone line side integrated ringer circuitry drawing substantially no loop current from the phone line during ringing conditions;

wherein the powered side circuitry is configured to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor;

wherein the phone line side circuitry is configured to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals;

wherein the powered side circuitry is further configured to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements, the clock signal being provided from the powered side circuitry to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor;

wherein the powered side circuitry and the phone line side circuitry are further configured so that power is capable of being provided from the powered side circuitry to the phone line side circuitry to generate at least one power supply within the phone line side circuitry, while still maintaining the isolation required by the phone line isolation regulatory standards; and

wherein at least one of the first digital differential signal and the second digital differential signal includes both data and control information.

12. The communication system of claim 11, further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry.

13. The communication system of claim 11, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

14. The communication system of claim 11, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.

15. The communication system of claim 11, wherein the phone line side circuitry and the powered side circuitry are configured to communicate across the isolation barrier through a digital signal.

16. The communication system of claim 15, further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry.

17. The communication system of claim 11, the phone line side integrated ringer circuitry operating from power supplied from across the isolation barrier.

18. The communication system of claim 17, further comprising:

the isolation barrier coupled between the phone line side circuitry and the powered side circuitry,

wherein the phone line side circuitry and the powered side circuitry are configured to communicate across the isolation barrier through a digital signal.

19. A method of providing a communication system for coupling to a phone line, comprising:

coupling an isolation barrier between a powered side circuitry and a phone line side circuitry, the isolation barrier comprising a plurality of isolation elements;

configuring the powered side circuitry to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor, wherein the powered side circuitry is configured to be isolated from the phone line in order to satisfy phone line isolation regulatory standards;

configuring the phone line side circuitry to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals, the phone line side circuitry further configured to provide an output signal for sending data to the phone line;

configuring the powered side circuitry to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements;

configuring the powered side circuitry and the phone line side circuitry so that power is capable of being provided from the powered side circuitry to the phone line side circuitry while still maintaining the isolation required by the phone line isolation regulatory standards;

partitioning ringer detection circuitry into a first integrated ringer circuit within the powered side circuitry and a second integrated ringer circuit within the phone line side circuitry; and

powering the second integrated ringer circuit portion by extracting power from a signal transmitted across the isolation barrier.

20. The method of claim 19, further comprising passing digital data across the isolation barrier.

21. The method of claim 19, further comprising drawing substantially no loop current from the phone line to operate the ringer detection circuitry.

22. The method of claim 21, further comprising passing digital data across the isolation barrier.

23. The method of claim 19, wherein the clock signal is provided from the powered side circuitry to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor.

24. The method of claim 19, wherein the first digital differential signal includes both data information and control information.

25. The method of claim 19, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

26. The method of claim 19, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.

27. A method of providing a communication system for coupling to a phone line, comprising:

coupling an isolation barrier between a powered side circuitry and a phone line side circuitry, the isolation barrier comprising a plurality of isolation elements;

configuring the powered side circuitry to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor, wherein the powered side circuitry is configured to be isolated from the phone line in order to satisfy phone line isolation regulatory standards;

configuring the phone line side circuitry to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein at least one of the first digital differential signal and the second digital differential signal includes both data and control information and wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals, the phone line side circuitry further configured to provide an output signal for sending data to a phone line;

configuring the powered side circuitry to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements, wherein the clock signal is provided from the powered side circuitry to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor; and

configuring the powered side circuitry and the phone line side circuitry so that power is capable of being provided from the powered side circuitry to the phone line side circuitry to generate at least one power supply within the phone line side circuitry, while still maintaining the isolation required by the phone line isolation regulatory standards,

partitioning ringer detection circuitry into a first integrated ringer circuit within the powered side circuitry and a second integrated ringer circuit within the phone line side circuitry; and

powering the second integrated ringer circuit portion by extracting power from a signal transmitted across the isolation barrier.

28. The method of claim 27, further comprising passing digital data across the isolation barrier.

29. The method of claim 27, further comprising drawing substantially no loop current from the phone line to operate the ringer detection circuitry.

30. The method of claim 29, further comprising passing digital data across the isolation barrier.

31. The method of claim 27, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

32. The method of claim 27, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.

33. A method for providing circuitry configured to isolate powered side circuitry from a phone line through a plurality of isolation barrier elements and of operating ringer detection circuitry to detect ringing conditions on the phone line, comprising:

configuring the powered side circuitry to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor, wherein the powered side circuitry is configured to be isolated from the phone line in order to satisfy phone line isolation regulatory standards;

configuring the phone line side circuitry to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals, the phone line side circuitry further configured to provide an output signal for sending data to the phone line;

configuring the powered side circuitry to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements;

configuring the powered side circuitry and the phone line side circuitry so that power is capable of being provided from the powered side circuitry to the phone line side circuitry while still maintaining the isolation required by the phone line isolation regulatory standards;

coupling the ringer detection circuitry to an input, the input provided for coupling to the phone line, and

drawing substantially no loop current from the phone line to operate the ringer detection circuitry during ringing conditions.

34. The method of claim 33, further comprising operating the ringer detection circuitry with a power supply which is generated from power transmitted across an isolation barrier.

35. The method of claim 33, wherein the clock signal is provided from the powered side circuitry to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor.

36. The method of claim 33, wherein the first digital differential signal includes both data information and control information.

37. The method of claim 33, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

38. The method of claim 33, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.

39. A method for providing circuitry configured to isolate powered side circuitry from a phone line through a plurality of isolation barrier elements and of operating ringer detection circuitry to detect ringing conditions on the phone line, comprising:

configuring the powered side circuitry to communicate a first digital differential signal to at least two of the isolation barrier elements, the at least two isolation barrier elements comprising at least a first isolation capacitor and a second isolation capacitor, wherein the powered side circuitry is configured to be isolated from the phone line in order to satisfy phone line isolation regulatory standards;

configuring the phone line side circuitry to communicate a second digital differential signal to the first isolation capacitor and the second isolation capacitor, wherein at least one of the first digital differential signal and the second digital differential signal includes both data and control information and wherein the first and second digital differential signals are communicated across the same first and second isolation capacitors so that the first and second isolation capacitors bidirectionally transfer the first and second digital differential signals, the phone line side circuitry further configured to provide an output signal for sending data to a phone line;

configuring the powered side circuitry to provide a clock signal to the phone line side circuitry through at least one of the plurality of isolation elements, wherein the clock signal is provided from the powered side circuitry to the phone line side circuitry through an isolation element that is separate from the first isolation capacitor and the second isolation capacitor; and

configuring the powered side circuitry and the phone line side circuitry so that power is capable of being provided from the powered side circuitry to the phone line side circuitry to generate at least one power supply within the phone line side circuitry, while still maintaining the isolation required by the phone line isolation regulatory standards,

coupling the ringer detection circuitry to an input, the input provided for coupling to the phone line, and

drawing substantially no loop current from the phone line to operate the ringer detection circuitry during ringing conditions.

40. The method of claim 39, further comprising operating the ringer detection circuitry with a power supply which is generated from power transmitted across an isolation barrier.

41. The method of claim 39, wherein each of said plurality of isolation elements of said isolation barrier comprises a capacitor.

42. The method of claim 39, wherein a portion of said plurality of isolation elements of said isolation barrier each comprises a capacitor.