摘要:
Telephone line service type identification is provided to a telephone technician in the field by the placement of one or more tuned circuit(s) across the telephone line. In one embodiment, an inexpensive tuned circuit such as a ceramic resonator forms a telecom service resonator ID device which is placed across a telephone line, either at the central office or at the customer premises. Injection of a test current at a predetermined frequency, and a suitable amplitude of the same indicates to the technician aspects of telecom service to that particular telephone line (e.g., the existence of POTS, ISDN, and/or xDSL) and or use of the telephone line by a home network such as HPNA. In another embodiment, a telecom service transponder ID device is formed to provide line service identification to an interrogating line technician. The telecom service transponder ID device is activated when the test signal including an appropriate frequency is present to cause excitation in the telecom service transponder ID device. The resonator and transponder devices preferably have very high impedances at all frequencies except at the desired resonant frequency, and thus avoids violation of telephone service standards. The resonator or transponder ID devices may be placed anywhere along the telephone line, but preferably at the customer premises, or in installed equipment utilizing the telephone line. More than one resonation frequency may be implemented with parallel tuned circuits to indicate additional features of service on the telephone line (e.g., the number of services, the existence of a data service, etc.). The frequencies of resonance of the tuned circuits are preferably chosen to exist between the spectrum utilized by the various operating services.
摘要:
A line powered data access arrangement (DAA) is disclosed which adaptively allows proper operation with power supplied from a telephone line as conditions warrant, while at the same time satisfying the relevant requirements of many countries. In the line powered codec, a startup procedure for the international line powered codec uses register settings, e.g., country-specific register settings, which are powered and maintained from the low voltage side (e.g., from the PC or modem side) of the line powered codec. In this way, even during low line power conditions the programmed state of the line powered codec can be maintained, thus a default condition will not necessarily returned to by the line powered codec upon reset due to a power loss in the telephone line. In another aspect, a charge storage device such as a charge capacitor is charged from a charge pump formed from a differential clock signal from the low voltage side. A current and voltage detection module in the line powered codec is always powered from the telephone line. Upon detection of an off-hook signal or a power down condition, the current detection module determines if/when the current and voltage on the telephone line is sufficient to power certain circuits on the line powered codec. If sufficient power is not present, the line powered codec does not power up. However, the line powered codec will power up if sufficient current is detected. In another aspect, a plurality of power rails may be provided. A first power rail may be associated with the line power, a second power rail may be associated with a low voltage side power source, e.g., a charge storage device. A third (and other) power rails may be switchably connected to either the first power rail or second power rail as line power conditions and on-hook/off-hook conditions warrant.
摘要:
In one embodiment, a low cost, simple circuit for detecting an off-hook condition of a telecommunication line comprising tip and ring signal lines is provided. The circuit comprises a voltage divider for coupling between the tip and ring lines without an intervening transistor and having a node at which is presented a scaled version of a voltage across the voltage divider. The circuit further comprises a transistor having a control terminal coupled to the node, a first current flow terminal coupled to a voltage source, and a second current flow terminal coupled to an output terminal, wherein the output terminal bears a value that is indicative of a voltage across the tip and ring lines and thus whether the telecommunication line is off-hook.
摘要:
In one embodiment, a low cost, simple circuit for detecting an off-hook condition of a telecommunication line comprising tip and ring signal lines is provided. The circuit comprises a voltage divider for coupling between the tip and ring lines without an intervening transistor and having a node at which is presented a scaled version of a voltage across the voltage divider. The circuit further comprises a transistor having a control terminal coupled to the node, a first current flow terminal coupled to a voltage source, and a second current flow terminal coupled to an output terminal, wherein the output terminal bears a value that is indicative of a voltage across the tip and ring lines and thus whether the telecommunication line is off-hook.
摘要:
A line powered data access arrangement (DAA) is disclosed which adaptively allows proper operation with power supplied from a telephone line as conditions warrant, while at the same time satisfying the relevant requirements of many countries. In the line powered codec, a startup procedure for the international line powered codec uses register settings, e.g., country-specific register settings, which are powered and maintained from the low voltage side (e.g., from the PC or modem side) of the line powered codec. In this way, even during low line power conditions the programmed state of the line powered codec can be maintained, thus a default condition will not necessarily returned to by the line powered codec upon reset due to a power loss in the telephone line. In another aspect, a charge storage device such as a charge capacitor is charged from a charge pump formed from a differential clock signal from the low voltage side. A current and voltage detection module in the line powered codec is always powered from the telephone line. Upon detection of an off-hook signal or a power down condition, the current detection module determines if/when the current and voltage on the telephone line is sufficient to power certain circuits on the line powered codec. If sufficient power is not present, the line powered codec does not power up. However, the line powered codec will power up if sufficient current is detected. In another aspect, a plurality of power rails may be provided. A first power rail may be associated with the line power, a second power rail may be associated with a low voltage side power source, e.g., a charge storage device. A third (and other) power rails may be switchably connected to either the first power rail or second power rail as line power conditions and on-hook/off-hook conditions warrant.
摘要:
Telephone line service type identification is provided to a telephone technician in the field by the placement of one or more tuned circuit(s) across the telephone line. In one embodiment, an inexpensive tuned circuit such as a ceramic resonator forms a telecom service resonator ID device which is placed across a telephone line, either at the central office or at the customer premises. Injection of a test current at a predetermined frequency, and a suitable amplitude of the same indicates to the technician aspects of telecom service to that particular telephone line (e.g., the existence of POTS, ISDN, and/or xDSL) and or use of the telephone line by a home network such as HPNA. In another embodiment, a telecom service transponder ID device is formed to provide line service identification to an interrogating line technician. The telecom service transponder ID device is activated when the test signal including an appropriate frequency is present to cause excitation in the telecom service transponder ID device. The resonator and transponder devices preferably have very high impedances at all frequencies except at the desired resonant frequency, and thus avoids violation of telephone service standards. The resonator or transponder ID devices may be placed anywhere along the telephone line, but preferably at the customer premises, or in installed equipment utilizing the telephone line. More than one resonation frequency may be implemented with parallel tuned circuits to indicate additional features of service on the telephone line (e.g., the number of services, the existence of a data service, etc.). The frequencies of resonance of the tuned circuits are preferably chosen to exist between the spectrum utilized by the various operating services. The transponder implementation may generate a simple low frequency response signal, or a more sophisticated specific data pattern using amplitude and/or frequency modulation.
摘要:
A line powered data access arrangement (DAA) is disclosed which adaptively allows proper operation with power supplied from a telephone line as conditions warrant, while at the same time satisfying the relevant requirements of many countries. In the line powered codec, a startup procedure for the international line powered codec uses register settings, e.g., country-specific register settings, which are powered and maintained from the low voltage side (e.g., from the PC or modem side) of the line powered codec. In this way, even during low line power conditions the programmed state of the line powered codec can be maintained, thus a default condition will not necessarily returned to by the line powered codec upon reset due to a power loss in the telephone line. In another aspect, a charge storage device such as a charge capacitor is charged from a charge pump formed from a differential clock signal from the low voltage side. A current and voltage detection module in the line powered codec is always powered from the telephone line. Upon detection of an off-hook signal or a power down condition, the current detection module determines if/when the current and voltage on the telephone line is sufficient to power certain circuits on the line powered codec. If sufficient power is not present, the line powered codec does not power up. However, the line powered codec will power up if sufficient current is detected. In another aspect, a plurality of power rails may be provided. A first power rail may be associated with the line power, a second power rail may be associated with a low voltage side power source, e.g., a charge storage device. A third (and other) power rails may be switchably connected to either the first power rail or second power rail as line power conditions and on-hook/off-hook conditions warrant.
摘要:
A line powered codec which adaptively allows operation with power supplied from a telephone line in many countries as conditions warrant. A startup procedure uses country-specific register settings, which are powered and maintained from a low voltage side other than the telephone line. Thus, during low line power conditions a programmed state of the line powered codec can be maintained even after a power loss in the telephone line. In another aspect, a current and voltage detection module in the line powered codec is always powered from the telephone line. If sufficient power is not present, the line powered codec does not power up. In yet another aspect, a plurality of power rails may be provided.