Low voltage circuits powered by the phone line

• US 20030206626A1
• Filed: 05/05/2003
• Published: 11/06/2003
• Est. Priority Date: 04/22/1997
• Status: Active Grant

• 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.
• Granted Patent: US 6,975,723 B2
• Time in Patent Office: Days
• US Class Current: 379/413
• 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 with a power supply budget such that portions of a phone line side circuit may be powered from the TIP and RING phone lines while using standard electronic devices for the hookswitch circuits and the diode bridge circuit. For example, low voltage converters in the phone line side circuit may be powered from the phone line. The low voltage converters may operate off a low voltage power supply of approximately 2.5 V or less, more preferably may operate off a low voltage power supply of approximately 2.0 V or less, and in one embodiment 1.9 V converters may be utilized. The communication system may further include a capacitive isolation barrier system for isolating the phone line side circuitry.

Claims

1. A communication system, comprising:

phone line side circuitry that may be coupled to phone lines;

powered side circuitry that may be coupled to the phone line side circuitry through an isolation barrier; and

low voltage circuits in an integrated portion of the phone line side circuitry, the low voltage circuits powered from the phone line and the low voltage circuits operating at sufficiently low voltage level so as not to require low voltage drop hookswitch devices and low voltage drop diode bridge diodes to couple the integrated portion of the phone line side circuitry to the phone line.

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

3. 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 digital signals.

4. The communication system of claim 3, further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry, the isolation barrier comprising one or more capacitors.

5. The communication system of claim 1 wherein the low voltage circuits are low voltage converters.

6. The communication system of claim 5, wherein the low voltage converters operate at a voltage supply level of 2.5 V or less.

7. The communication system of claim 6, wherein the low voltage converters operate at a voltage supply level of 2.0 V or less.

8. The communication system of claim 5, wherein the low voltage circuits operate at a voltage supply level of 2.5 V or less, the system further comprising the isolation barrier coupled between the phone line side circuitry and the powered side circuitry, the isolation barrier comprising one or more capacitors, wherein the phone line side circuitry and the powered side circuitry communicate across the isolation barrier through digital signals.

9. A method of providing a communication system that may be coupled to a phone line, comprising:

coupling an isolation barrier between powered circuitry and phone line side circuitry; and

operating low voltage circuits in an integrated portion of the phone line side circuitry from power supplied from the phone line at a sufficiently low voltage level so as not to require low voltage drop hookswitch devices and low voltage drop diode bridge diodes to couple the integrated portion of the phone line side circuitry to the phone line.

10. The method of claim 9, further comprising utilizing a capacitive barrier to isolate the powered circuitry and the phone line circuitry.

11. The method of claim 9, further comprising passing digital data across the isolation barrier.

12. The method of claim 11, further comprising utilizing a capacitive barrier to isolate the powered circuitry and the phone line circuitry.

13. The method of claim 9, further comprising operating the low voltage circuits at a voltage level of 2.5 V or less.

14. The method of claim 13 wherein the low voltage circuits are low voltage converters.

15. The method of claim 14, further comprising utilizing a capacitive barrier to isolate the powered circuitry and the phone line circuitry and passing digital data across the isolation barrier.

16. An electrical circuit connectable to a phone line, comprising:

an integrated circuit; and

at least one low voltage converter within the integrated circuit and coupled to the phone line, the low voltage converter being powered from the phone line,

wherein the low voltage converter is supplied with through a node coupled to the phone line, the node having a voltage level of 2.5 V or less.

17. The electrical circuit of claim 16, the voltage level being 2.0 V or less.

18. The electrical circuit of claim 16, the voltage level being sufficiently low so as to allow coupling of the integrated circuit portion to the phone line through hookswitch devices and diode bridge devices without the hookswitch devices and diode bridge devices being low voltage drop devices.

19. The electrical circuit of claim 16 wherein low voltage converters are operable even if the hookswitch devices have a voltage drop of approximately 1 V or greater and the diode bridge has a voltage drop of approximately 1.4 V or greater.

20. A method of powering at least a portion of an integrated circuit for use in terminating a phone line, comprising:

coupling a low voltage circuit within the integrated circuit to at least one external device;

coupling the at least one external device to TIP and RING phone lines; and

supplying a voltage from the TIP and RING phone lines to the low voltage circuit, the voltage being at a level of 2.5 V or less at an input to the low voltage circuit.

21. The method of claim 20 wherein the voltage is at a level of 2.0 V or less.

22. The method of claim 20 wherein the low voltage circuit is an analog to digital converter or a digital to analog converter.

23. The method of claim 22, the at least one external device comprising a hookswitch device and a diode bridge, the low voltage circuit operating at a voltage level sufficiently low so as not to require low voltage drop hookswitch devices and low voltage drop diode bridge diodes.

24. The method of claim 23, the hookswitch device providing power to the low voltage circuit during both on-hook and off-hook conditions.