Line driver method and apparatus

• US 8,896,351 B2
• Filed: 03/19/2008
• Issued: 11/25/2014
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Intel Germany GmbH (Intel Corporation)
• Original Assignee: Lantiq Deutschland GMBH (Intel Corporation)
• Inventors: Wenske, Holger, Eichler, Thomas, Traber, Mario
• Primary Examiner(s): LUU, AN T
• Application Number:
  US12/051,254
• Publication Number:
  US 20090237122A1
• Time in Patent Office: 2,442 Days
• Field of Search: 327108-112, 327/379, 327/389, 327/391, 326 21- 24, 326 26- 27, 326/30, 326 82- 83, 326/87
• US Class Current: 327/108
• CPC Class Codes: H04L 25/0264 Arrangements for coupling to transmission lines duplexing arrangements H04L5/14; line equalisers, line build-out devices H04L25/03878

Abstract

According to one embodiment, a line driver circuit comprises a plurality of output stages each operable to produce an output signal and one or more pre-output stages operable to perform one or more common functions. The line driver circuit also comprises circuitry operable to selectively couple one or more of the output stages to the one or more pre-output stages based on a wireline communication technology implemented by the line driver circuit.

Claims

1. A line driver circuit, comprising:

a plurality of output stages each operable to produce an output signal in compliance with a wireline communication technology;

a pre-output stage operable to perform one or more functions common to the plurality of output stages; and

circuitry operable to determine which wireline communication technology is implemented by the line driver circuit based on a mode input provided to the circuitry, couple to the pre-output stage each output stage operable to produce an output signal that complies with the wireline communication technology indicated by the mode input, and decouple from the pre-output stage each output stage that is not operable to produce an output signal that complies with the wireline communication technology indicated by the mode input,

wherein each output stage comprises an amplifier and feedback and feed-forward impedances selectively coupled between the amplifier and the pre-output stage.

2. The line driver circuit of claim 1, wherein the mode input is programmable and the circuitry is operable to reconfigure which of the plurality of output stages are coupled to the pre-output stage and which of the plurality of output stages are decoupled from the pre-output stage responsive to a change in the mode input.

3. The line driver circuit of claim 1, wherein the circuitry comprises:

a first group of switches operable to selectively couple and decouple different ones of the plurality of output stages to the pre-output stage based on the mode input; and

a second group of switches operable to deactivate each output stage decoupled from the pre-output stage.

4. The line driver circuit of claim 1, wherein the pre-output stage comprises biasing circuitry operable to bias each output stage coupled to the pre-output stage.

5. The line driver circuit of claim 4, wherein the amount of bias provided by the biasing circuitry is programmable based on the number and performance requirements of the output stages coupled to the pre-output stage.

6. The line driver circuit of claim 1, wherein the mode input is hardwired.

7. The line driver circuit of claim 1, wherein the circuitry is operable to couple to the pre-output stage each output stage operable to produce an output signal which satisfies voltage and current conditions associated with the wireline communication technology indicated by the mode input.

8. The line driver circuit of claim 1, wherein one or more of the plurality of output stages are operable to meet signal requirements for a xDSL technology when coupled to the pre-output stage, and wherein one or more different ones of the plurality of output stages are operable to meet signal requirements for an E-carrier technology or T-carrier technology when coupled to the pre-output stage.

9. The line driver circuit of claim 1, wherein at least one of the plurality of output stages comprises:

a voltage-mode line driver having an input, an output and an output impedance;

a feedback impedance coupled between the output and the input of the voltage-mode line driver;

a feed-forward impedance coupled between the input and the output of the voltage-mode line driver;

a termination impedance coupled between the output of the voltage-mode line driver and a transmission line and operable to sense current and voltage output by the voltage-mode line driver;

wherein the output impedance of the voltage-mode line driver is synthesized based on the feedback and feed-forward impedances;

wherein a total output impedance of the output stage corresponds to the output impedance of the voltage-mode line driver and the termination impedance and approximately matches an impedance of the transmission line; and

wherein the magnitude of the termination impedance corresponds approximately to the difference between the transmission line impedance and the output impedance of the voltage-mode line driver.

10. A line driver circuit, comprising:

a plurality of output stages each operable to produce an output signal in compliance with a wireline communication technology;

a pre-output stage operable to perform one or more functions common to the plurality of output stages; and

circuitry operable to determine which wireline communication technology is implemented by the line driver circuit based on a mode input provided to the circuitry, couple to the pre-output stage each output stage operable to produce an output signal that complies with the wireline communication technology indicated by the mode input, and decouple from the pre-output stage each output stage that is not operable to produce an output signal that complies with the wireline communication technology indicated by the mode input,

wherein the plurality of output stages are operable to meet signal requirements for at

least two different ones of 1OBASE-T Ethernet, 1OOBASE-T Ethernet, Gigabit Ethernet, 10 Gigabit Ethernet and 100 Gigabit Ethernet when coupled to the pre-output stage, or

wherein one or more of the plurality of output stages are operable to meet signal requirements for a xDSL technology when coupled to the pre-output stage, and wherein one or more different ones of the plurality of output stages are operable to meet signal requirements for an E-carrier technology or T-carrier technology when coupled to the pre-output stage.

11. A method of configuring a line drive circuit, comprising:

providing a plurality of output stages each operable to produce an output signal in compliance with a wireline communication technology;

providing a pre-output stage operable to perform one or more functions common to the plurality of output stages;

determining which wireline communication technology is implemented by the line driver circuit based on a mode input;

coupling to the pre-output stage each output stage operable to produce an output signal that complies with the wireline communication indicated by the mode input; and

decoupling from the pre-output stage each output stage that is not operable to produce an output signal that complies with the wireline communication technology indicated by the mode input, and

programming an amount of bias provided to each output stage coupled to the pre-output stage based on the number of output stages coupled to the pre-output stage.

12. The method of claim 11, comprising selectively coupling one or more inverting amplifiers to the pre-output stage based on the mode input.

13. The method of claim 11, comprising reconfiguring which of the plurality output stages are coupled to the pre-output stage and which of the plurality of output stages are decoupled from the pre-output stage responsive to a change in the mode input.

14. The method of claim 13, comprising reconfiguring which of the plurality output stages are coupled to the pre-output stage and which of the plurality of output stages are decoupled from the pre-output stage responsive to the mode input indicating a change from one Ethernet technology to another Ethernet technology.

15. The method of claim 13, comprising reconfiguring which of the plurality output stages are coupled to the pre-output stage and which of the plurality of output stages are decoupled from the pre-output stage responsive to the mode input indicating a change from a digital subscriber loop technology to an E-carrier technology or T-carrier technology or from the E-carrier technology or the T-carrier technology to the digital subscriber loop technology.

16. The method of claim 11, comprising applying a ground potential to an n-FET transistor and a voltage potential to a p-FET transistor included in each inverting amplifier decoupled from the stage.