Modem having an improved line interface circuit, in particular for a computer

Claim 2

Circuitry for providing a telephone line interface circuit of a MODEM for a computer with an AC impedance and DC voltage/current characteristics required by a given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network, wherein the given type telephone network provides an identification code representative of the required AC impedance and DC voltage/current characteristics, wherein the circuitry comprises: (A) a plurality of impedance components, wherein the plurality of impedance components, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit; (B) a plurality of terminals coupled to receive a plurality of control signals associated with the identification code; (C) a switching logic coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the required AC impedance and DC voltage/current characteristics; and (D) an identifying circuit coupled to the given type telephone network and the plurality of terminals for identifying the required AC impedance and DC voltage/current characteristics by receiving the identification code and converting the identification code into the plurality of control signals, wherein the identifying circuit automatically receives the identification code from a connector of the given type of telephone network absent of any control from a user of the MODEM when the MODEM is connected to the connector of the given type of telephone network, wherein the identification code is a hardware implemented value.

Claim 3

The circuitry of claim 1, wherein the plurality of impedance components comprise resistors, capacitors, inductors, diodes, Zener diodes, and transistors.

Claim 4

The circuitry of claim 2, wherein the plurality of impedance components further comprise a positive temperature coefficient thermistor.

Claim 5

The circuitry of claim 1, wherein the switching logic comprises semiconductor switches and optocouplers.

Claim 6

The circuitry of claim 1, wherein the identifying circuit receives the identification code from an electronic component in a connector that couples the telephone line interface circuit to the given type telephone network, wherein the value of the electronic component is associated with the identification code.

Claim 7

The circuitry of claim 5, wherein the electronic component is selected from a group of elements comprising resistors, capacitors, inductors, diodes, Zener diodes, and combinations thereof.

Claim 8

A MODEM for a computer, comprising: (A) a connector for coupling the MODEM to a given type telephone network, wherein the connector includes an identification code representative of an AC impedance and DC voltage/current characteristics required by the given type telephone network, wherein the identification code is a hardware implemented value in the connector; (B) a telephone line interface circuit coupled to the given type telephone network via the connector; (C) circuitry coupled to the telephone line interface circuit and the connector for providing the telephone line interface circuit with the AC impedance and DC voltage/current characteristics required by the given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network via the connector, wherein the circuitry further comprises (i) a plurality of impedance components, wherein the plurality of impedance components, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit; (ii) a plurality of terminals coupled to receive a plurality of control signals associated with the identification code; (iii) a switching logic coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the required AC impedance and DC voltage/current characteristics; and (iv) an identifying circuit coupled to the connector and the plurality of terminals for identifying the required AC impedance and DC voltage/current characteristics by receiving the identification code from the connector and converting the identification code into the plurality of control signals, wherein the identification circuit automatically receives the identification code from the connector absent of any control from a user of the MODEM when the circuitry is coupled to the connector.

Claim 9

A MODEM for a computer, comprising: (A) a connector for coupling the MODEM to a given type telephone network, wherein the connector includes an identification code representative of an AC impedance and DC voltage/current characteristics required by the given type telephone network, wherein the identification code is a hardware implemented value in the connector; (B) a telephone line interface circuit coupled to the given type telephone network via the connector; (C) circuitry coupled to the telephone line interface circuit and the connector for providing the telephone line interface circuit with the AC impedance and DC voltage/current characteristics required by the given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network via the connector, wherein the circuitry further comprises (i) a plurality of impedance components, wherein the plurality of impedance components, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit; (ii) a plurality of terminals coupled to receive a plurality of control signals associated with the identification code; (iii) a switching logic coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the required AC impedance and DC voltage/current characteristics; and (iv) an identifying circuit coupled to the connector and the plurality of terminals for identifying the required AC impedance and DC voltage/current characteristics by receiving the identification code from the connector and converting the identification code into the plurality of control signals, wherein the identification circuit automatically receives the identification code from the connector absent of any control from a user of the MODEM when the circuitry is coupled to the connector.

Claim 10

The MODEM of claim 7, wherein the connector further comprises a resistor the resistance of which determines the identification code.

Claim 11

The MODEM of claims 7, wherein the connector further comprises a capacitor the capacitance of which determines the identification code.

Claim 12

The MODEM of claim 7, wherein the connector further comprises an inductor the inductance of which determines the identification code.

Claim 13

The MODEM of claim 7, wherein the connector further comprises a diode the bias voltage of which determines the identification code.

Claim 14

The MODEM of claim 7, wherein the connector further comprises a filter the cut-off frequency of which determines the identification code.

Claim 15

The MODEM of claim 7, wherein the connector further comprises a plurality of jumps the presence of which determines the identification code.

Claim 16

A computer system, comprising: (A) a host computer circuit; (B) a MODEM coupled to the host computer circuit for coupling the host computer circuit to a given type of telephone network for data transmission, wherein the MODEM further comprises (a) a connector for coupling the MODEM to the given type telephone network, wherein the connector includes an identification code representative of an AC impedance and DC voltage/current characteristics required by the given type telephone network, wherein the identification code is a hardware implemented value in the connector; (b) a telephone line interface circuit coupled to the given type telephone network via the connector; (c) circuitry coupled to the telephone line interface circuit and the connector for providing the telephone line interface circuit with the AC impedance and DC voltage/current characteristics required by the given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network via the connector, wherein the circuitry further comprises (i) a plurality of impedance components, wherein the plurality of impedance components, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit; (ii) a plurality of terminals coupled to receive a plurality of control signals associated with the identification code; (iii) a switching logic coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the required AC impedance and DC voltage/current characteristics; and (iv) an identifying circuit coupled to the connector and the plurality of terminals for identifying the required AC impedance and DC voltage/current characteristics by receiving the identification code from the connector and converting the identification code into the plurality of control signals, wherein the identification circuit automatically receives the identification code from the connector absent of any control from a user of the MODEM when the circuitry is coupled to the connector.

Claim 17

A computer system, comprising: (A) a host computer circuit; (B) a MODEM coupled to the host computer circuit for coupling the host computer circuit to a given type of telephone network for data transmission, wherein the MODEM further comprises (a) a connector for coupling the MODEM to the given type telephone network, wherein the connector includes an identification code representative of an AC impedance and DC voltage/current characteristics required by the given type telephone network, wherein the identification code is a hardware implemented value in the connector; (b) a telephone line interface circuit coupled to the given type telephone network via the connector; (c) circuitry coupled to the telephone line interface circuit and the connector for providing the telephone line interface circuit with the AC impedance and DC voltage/current characteristics required by the given type telephone network such that the telephone line interface circuit can be matchingly connected with the given type telephone network via the connector, wherein the circuitry further comprises (i) a plurality of impedance components, wherein the plurality of impedance components, when connected to the telephone line interface circuit, determine the AC impedance and DC voltage/current characteristics of the telephone line interface circuit; (ii) a plurality of terminals coupled to receive a plurality of control signals associated with the identification code; (iii) a switching logic coupled (1) between the plurality of impedance components and the telephone line interfacing circuit and (2) to the plurality of terminals for selectively connecting the plurality of impedance components to the telephone line interface circuit under the control of the plurality of control signals so as to cause the telephone line interface circuit to have the required AC impedance and DC voltage/current characteristics; and (iv) an identifying circuit coupled to the connector and the plurality of terminals for identifying the required AC impedance and DC voltage/current characteristics by receiving the identification code from the connector and converting the identification code into the plurality of control signals, wherein the identification circuit automatically receives the identification code from the connector absent of any control from a user of the MODEM when the circuitry is coupled to the connector.

Claim 18

The computer system of claim 14, wherein the identifying circuit receives the identification code from an electronic component in the connector, wherein the value of the electronic component is associated with the identification code.

Claim 19

The computer system of claim 15, wherein the electronic component is selected from a group of elements comprising resistors, capacitors, inductors, diodes, Zener diodes, and combinations thereof.

Claim 20

The computer system of claim 14, wherein the plurality of impedance components comprise resistors, capacitors, inductors, diodes, Zener diodes, and transistors.

Claim 21

The computer system of claim 14, wherein the switching logic comprises semiconductor switches and optocouplers.